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http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #HicEst | HicEst |
CHARACTER Fnam = "\HicEst\Rosetta\Align columns.txt"
OPEN(FIle=Fnam, Format="12$", LENgth=rows)
! call the DLG function in MatrixExplorer mode:
DLG(Edit=Fnam, Format='12A10') ! left adjusted, 12 columns, 10 spaces each
! or the standard way:
CALL Align( "LLLLLLLLLLL ", Fnam, rows) ! left align
CALL Align( "CCCCCCCCCCC ", Fnam, rows) ! center align
CALL Align( "RRRRRRRRRRR ", Fnam, rows) ! right align
END
SUBROUTINE Align(picture, filename, rows)
CHARACTER picture, filename
CHARACTER out*400, txt*20
W = LEN(picture)
DO i = 1, rows
out = " "
DO j = 0, 100
txt = filename(i, j+1, *9) ! on error branch to label 9
WRITE(Text=out(j*W+1 : ), Format=picture) txt
ENDDO
9 CONTINUE
WRITE() out
ENDDO
END |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Ruby | Ruby | require 'polynomial'
def x_minus_1_to_the(p)
return Polynomial.new(-1,1)**p
end
def prime?(p)
return false if p < 2
(x_minus_1_to_the(p) - Polynomial.from_string("x**#{p}-1")).coefs.all?{|n| n%p==0}
end
8.times do |n|
# the default Polynomial#to_s would be OK here; the substitutions just make the
# output match the other version below.
puts "(x-1)^#{n} = #{x_minus_1_to_the(n).to_s.gsub(/\*\*/,'^').gsub(/\*/,'')}"
end
puts "\nPrimes below 50:", 50.times.select {|n| prime? n}.join(',') |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Maxima | Maxima | read_file(name) := block([file, s, L], file: openr(name), L: [],
while stringp(s: readline(file)) do L: cons(s, L), close(file), L)$
u: read_file("C:/my/mxm/unixdict.txt")$
v: map(lambda([s], [ssort(s), s]), u)$
w: sort(v, lambda([x, y], orderlessp(x[1], y[1])))$
ana(L) := block([m, n, p, r, u, v, w],
L: endcons(["", ""], L),
n: length(L),
r: "",
m: 0,
v: [ ],
w: [ ],
for i from 1 thru n do (
u: L[i],
if r = u[1] then (
w: cons(u[2], w)
) else (
p: length(w),
if p >= m then (
if p > m then (m: p, v: []),
v: cons(w, v)
),
w: [u[2]],
r: u[1]
)
),
v)$
ana(w);
/* [["evil", "levi", "live", "veil", "vile"],
["elan", "lane", "lean", "lena", "neal"],
["alger", "glare", "lager", "large", "regal"],
["angel", "angle", "galen", "glean", "lange"],
["caret", "carte", "cater", "crate", "trace"],
["abel", "able", "bale", "bela", "elba"]] */ |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #Wart | Wart | def (fib n)
if (n >= 0)
(transform n :thru (afn (n)
(if (n < 2)
n
(+ (self n-1)
(self n-2))))) |
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #VBScript | VBScript | start = Now
Set nlookup = CreateObject("Scripting.Dictionary")
Set uniquepair = CreateObject("Scripting.Dictionary")
For i = 1 To 20000
sum = 0
For n = 1 To 20000
If n < i Then
If i Mod n = 0 Then
sum = sum + n
End If
End If
Next
nlookup.Add i,sum
Next
For j = 1 To 20000
sum = 0
For m = 1 To 20000
If m < j Then
If j Mod m = 0 Then
sum = sum + m
End If
End If
Next
If nlookup.Exists(sum) And nlookup.Item(sum) = j And j <> sum _
And uniquepair.Exists(sum) = False Then
uniquepair.Add j,sum
End If
Next
For Each key In uniquepair.Keys
WScript.Echo key & ":" & uniquepair.Item(key)
Next
WScript.Echo "Execution Time: " & DateDiff("s",Start,Now) & " seconds" |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a variable number of expressions (or values if that's simpler in the language) and yields a correct one which will satisfy a constraint in some future computation, thereby avoiding failure.
Problems whose solution the Amb operator naturally expresses can be approached with other tools, such as explicit nested iterations over data sets, or with pattern matching. By contrast, the Amb operator appears integrated into the language. Invocations of Amb are not wrapped in any visible loops or other search patterns; they appear to be independent.
Essentially Amb(x, y, z) splits the computation into three possible futures: a future in which the value x is yielded, a future in which the value y is yielded and a future in which the value z is yielded. The future which leads to a successful subsequent computation is chosen. The other "parallel universes" somehow go away. Amb called with no arguments fails.
For simplicity, one of the domain values usable with Amb may denote failure, if that is convenient. For instance, it is convenient if a Boolean false denotes failure, so that Amb(false) fails, and thus constraints can be expressed using Boolean expressions like Amb(x * y == 8) which unless x and y add to four.
A pseudo-code program which satisfies this constraint might look like:
let x = Amb(1, 2, 3)
let y = Amb(7, 6, 4, 5)
Amb(x * y = 8)
print x, y
The output is 2 4 because Amb(1, 2, 3) correctly chooses the future in which x has value 2, Amb(7, 6, 4, 5) chooses 4 and consequently Amb(x * y = 8) produces a success.
Alternatively, failure could be represented using strictly Amb():
unless x * y = 8 do Amb()
Or else Amb could take the form of two operators or functions: one for producing values and one for enforcing constraints:
let x = Ambsel(1, 2, 3)
let y = Ambsel(4, 5, 6)
Ambassert(x * y = 8)
print x, y
where Ambassert behaves like Amb() if the Boolean expression is false, otherwise it allows the future computation to take place, without yielding any value.
The task is to somehow implement Amb, and demonstrate it with a program which chooses one word from each of the following four sets of character strings to generate a four-word sentence:
"the" "that" "a"
"frog" "elephant" "thing"
"walked" "treaded" "grows"
"slowly" "quickly"
The constraint to be satisfied is that the last character of each word (other than the last) is the same as the first character of its successor.
The only successful sentence is "that thing grows slowly"; other combinations do not satisfy the constraint and thus fail.
The goal of this task isn't to simply process the four lists of words with explicit, deterministic program flow such as nested iteration, to trivially demonstrate the correct output. The goal is to implement the Amb operator, or a facsimile thereof that is possible within the language limitations.
| #VBScript | VBScript | class ambiguous
dim sRule
public property let rule( x )
sRule = x
end property
public default function amb(p1, p2)
amb = eval(sRule)
end function
end class |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #R | R | accumulatorFactory <- function(init) {
currentSum <- init
function(add) {
currentSum <<- currentSum + add
currentSum
}
} |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Racket | Racket | #lang racket
(define ((accumulator n) i)
(set! n (+ n i))
n)
|
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #Clay | Clay | ackermann(m, n) {
if(m == 0)
return n + 1;
if(n == 0)
return ackermann(m - 1, 1);
return ackermann(m - 1, ackermann(m, n - 1));
} |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #GFA_Basic | GFA Basic |
num_deficient%=0
num_perfect%=0
num_abundant%=0
'
FOR current%=1 TO 20000
sum_divisors%=@sum_proper_divisors(current%)
IF sum_divisors%<current%
num_deficient%=num_deficient%+1
ELSE IF sum_divisors%=current%
num_perfect%=num_perfect%+1
ELSE ! sum_divisors%>current%
num_abundant%=num_abundant%+1
ENDIF
NEXT current%
'
' Display results on a window
'
OPENW 1
CLEARW 1
PRINT "Number deficient ";num_deficient%
PRINT "Number perfect ";num_perfect%
PRINT "Number abundant ";num_abundant%
~INP(2)
CLOSEW 1
'
' Compute the sum of proper divisors of given number
'
FUNCTION sum_proper_divisors(n%)
LOCAL i%,sum%,root%
'
IF n%>1 ! n% must be 2 or higher
sum%=1 ! start with 1
root%=SQR(n%) ! note that root% is an integer
' check possible factors, up to sqrt
FOR i%=2 TO root%
IF n% MOD i%=0
sum%=sum%+i% ! i% is a factor
IF i%*i%<>n% ! check i% is not actual square root of n%
sum%=sum%+n%/i% ! so n%/i% will also be a factor
ENDIF
ENDIF
NEXT i%
ENDIF
RETURN sum%
ENDFUNC
|
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Icon_and_Unicon | Icon and Unicon | global width
procedure main(args)
lines := []
width := 0
format := left
match("left"|"right"|"center", format <- !args)
every put(lines,prepare(!&input))
display(lines, proc(format,3))
end
procedure prepare(lines)
line := []
lines ? {
while (not pos(0)) & (field := tab(upto('$')|0)) do {
put(line, field)
width <:= *field
move(1)
}
}
return line
end
procedure display(lines, format)
width +:= 1
every line := !lines do {
every writes(format(!line, width))
write()
}
end |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Rust | Rust | fn aks_coefficients(k: usize) -> Vec<i64> {
let mut coefficients = vec![0i64; k + 1];
coefficients[0] = 1;
for i in 1..(k + 1) {
coefficients[i] = -(1..i).fold(coefficients[0], |prev, j|{
let old = coefficients[j];
coefficients[j] = old - prev;
old
});
}
coefficients
}
fn is_prime(p: usize) -> bool {
if p < 2 {
false
} else {
let c = aks_coefficients(p);
(1..p / 2 + 1).all(|i| c[i] % p as i64 == 0)
}
}
fn main() {
for i in 0..8 {
println!("{}: {:?}", i, aks_coefficients(i));
}
for i in (1..=50).filter(|&i| is_prime(i)) {
print!("{} ", i);
}
} |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #MUMPS | MUMPS | Anagrams New ii,file,longest,most,sorted,word
Set file="unixdict.txt"
Open file:"r" Use file
For Quit:$ZEOF DO
. New char,sort
. Read word Quit:word=""
. For ii=1:1:$Length(word) Do
. . Set char=$ASCII(word,ii)
. . If char>64,char<91 Set char=char+32
. . Set sort(char)=$Get(sort(char))+1
. . Quit
. Set (sorted,char)="" For Set char=$Order(sort(char)) Quit:char="" Do
. . For ii=1:1:sort(char) Set sorted=sorted_$Char(char)
. . Quit
. Set table(sorted,word)=1
. Quit
Close file
Set sorted="" For Set sorted=$Order(table(sorted)) Quit:sorted="" Do
. Set ii=0,word="" For Set word=$Order(table(sorted,word)) Quit:word="" Set ii=ii+1
. Quit:ii<2
. Set most(ii,sorted)=1
. Quit
Write !,"The anagrams with the most variations:"
Set ii=$Order(most(""),-1)
Set sorted="" For Set sorted=$Order(most(ii,sorted)) Quit:sorted="" Do
. Write ! Set word="" For Set word=$Order(table(sorted,word)) Quit:word="" Write " ",word
. Quit
Write !,"The longest anagrams:"
Set ii=$Order(longest(""),-1)
Set sorted="" For Set sorted=$Order(longest(ii,sorted)) Quit:sorted="" Do
. Write ! Set word="" For Set word=$Order(table(sorted,word)) Quit:word="" Write " ",word
. Quit
Quit
Do Anagrams |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #WDTE | WDTE | let str => 'strings';
let fib n => switch n {
< 0 => str.format 'Bad argument: {q}' n;
default => n -> (@ memo s n => switch n {
== 0 => 0; == 1 => 1;
default => + (s (- n 1)) (s (- n 2));
});
}; |
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #Vlang | Vlang | fn pfac_sum(i int) int {
mut sum := 0
for p := 1;p <= i/2;p++{
if i%p == 0 {
sum += p
}
}
return sum
}
fn main(){
a := []int{len: 20000, init:pfac_sum(it)}
println('The amicable pairs below 20,000 are:')
for n in 2 .. a.len {
m := a[n]
if m > n && m < 20000 && n == a[m] {
println('${n:5} and ${m:5}')
}
}
} |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a variable number of expressions (or values if that's simpler in the language) and yields a correct one which will satisfy a constraint in some future computation, thereby avoiding failure.
Problems whose solution the Amb operator naturally expresses can be approached with other tools, such as explicit nested iterations over data sets, or with pattern matching. By contrast, the Amb operator appears integrated into the language. Invocations of Amb are not wrapped in any visible loops or other search patterns; they appear to be independent.
Essentially Amb(x, y, z) splits the computation into three possible futures: a future in which the value x is yielded, a future in which the value y is yielded and a future in which the value z is yielded. The future which leads to a successful subsequent computation is chosen. The other "parallel universes" somehow go away. Amb called with no arguments fails.
For simplicity, one of the domain values usable with Amb may denote failure, if that is convenient. For instance, it is convenient if a Boolean false denotes failure, so that Amb(false) fails, and thus constraints can be expressed using Boolean expressions like Amb(x * y == 8) which unless x and y add to four.
A pseudo-code program which satisfies this constraint might look like:
let x = Amb(1, 2, 3)
let y = Amb(7, 6, 4, 5)
Amb(x * y = 8)
print x, y
The output is 2 4 because Amb(1, 2, 3) correctly chooses the future in which x has value 2, Amb(7, 6, 4, 5) chooses 4 and consequently Amb(x * y = 8) produces a success.
Alternatively, failure could be represented using strictly Amb():
unless x * y = 8 do Amb()
Or else Amb could take the form of two operators or functions: one for producing values and one for enforcing constraints:
let x = Ambsel(1, 2, 3)
let y = Ambsel(4, 5, 6)
Ambassert(x * y = 8)
print x, y
where Ambassert behaves like Amb() if the Boolean expression is false, otherwise it allows the future computation to take place, without yielding any value.
The task is to somehow implement Amb, and demonstrate it with a program which chooses one word from each of the following four sets of character strings to generate a four-word sentence:
"the" "that" "a"
"frog" "elephant" "thing"
"walked" "treaded" "grows"
"slowly" "quickly"
The constraint to be satisfied is that the last character of each word (other than the last) is the same as the first character of its successor.
The only successful sentence is "that thing grows slowly"; other combinations do not satisfy the constraint and thus fail.
The goal of this task isn't to simply process the four lists of words with explicit, deterministic program flow such as nested iteration, to trivially demonstrate the correct output. The goal is to implement the Amb operator, or a facsimile thereof that is possible within the language limitations.
| #Wren | Wren | var finalRes = []
var amb // recursive closure
amb = Fn.new { |wordsets, res|
if (wordsets.count == 0) {
finalRes.addAll(res)
return true
}
var s = ""
var l = res.count
if (l > 0) s = res[l-1]
res.add("")
for (word in wordsets[0]) {
res[l] = word
if (l > 0 && s[-1] != res[l][0]) continue
if (amb.call(wordsets[1..-1], res.toList)) return true
}
return false
}
var wordsets = [
[ "the", "that", "a" ],
[ "frog", "elephant", "thing" ],
[ "walked", "treaded", "grows" ],
[ "slowly", "quickly" ]
}
if (amb.call(wordsets, [])) {
System.print(finalRes.join(" "))
} else {
System.print("No amb found")
} |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Raku | Raku | sub accum ($n is copy) { sub { $n += $^x } }
#Example use:
my $a = accum 5;
$a(4.5);
say $a(.5); # Prints "10".
# You can also use the "&" sigil to create a function that behaves syntactically
# like any other function (i.e. no sigil nor parentheses needed to call it):
my &b = accum 5;
say b 3; # Prints "8". |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #REBOL | REBOL | make-acc-gen: func [start-val] [
use [state] [
state: start-val
func [value] [
state: state + value
]
]
] |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #CLIPS | CLIPS | (deffunction ackerman
(?m ?n)
(if (= 0 ?m)
then (+ ?n 1)
else (if (= 0 ?n)
then (ackerman (- ?m 1) 1)
else (ackerman (- ?m 1) (ackerman ?m (- ?n 1)))
)
)
) |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #Go | Go | package main
import "fmt"
func pfacSum(i int) int {
sum := 0
for p := 1; p <= i/2; p++ {
if i%p == 0 {
sum += p
}
}
return sum
}
func main() {
var d, a, p = 0, 0, 0
for i := 1; i <= 20000; i++ {
j := pfacSum(i)
if j < i {
d++
} else if j == i {
p++
} else {
a++
}
}
fmt.Printf("There are %d deficient numbers between 1 and 20000\n", d)
fmt.Printf("There are %d abundant numbers between 1 and 20000\n", a)
fmt.Printf("There are %d perfect numbers between 1 and 20000\n", p)
} |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #J | J | 'LEFT CENTER RIGHT'=: i.3 NB. justification constants
NB.* alignCols v Format delimited text in justified columns
NB. y: text to format
NB. rows marked by last character in text
NB. columns marked by $
NB. optional x: justification. Default is LEFT
NB. result: text table
alignCols=: verb define
LEFT alignCols y NB. default
:
global=. dyad def'9!:x y'each
oldbox=. 6 16 global '';'' NB. save settings
7 17 global (11#' ');,~x NB. apply new settings
result=. _2{:\ ": <;._2 @:,&'$';._2 y NB. parse & format text
7 17 global oldbox NB. restore settings
result
) |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Scala | Scala | def powerMin1(n: BigInt) = if (n % 2 == 0) BigInt(1) else BigInt(-1)
val pascal = (( Vector(Vector(BigInt(1))) /: (1 to 50)) { (rows, i) =>
val v = rows.head
val newVector = ((1 until v.length) map (j =>
powerMin1(j+i) * (v(j-1).abs + v(j).abs))
).toVector
(powerMin1(i) +: newVector :+ powerMin1(i+v.length)) +: rows
}).reverse
def poly2String(poly: Vector[BigInt]) = ((0 until poly.length) map { i =>
(i, poly(i)) match {
case (0, c) => c.toString
case (_, c) =>
(if (c >= 0) "+" else "-") +
(if (c == 1) "x" else c.abs + "x") +
(if (i == 1) "" else "^" + i)
}
}) mkString ""
def isPrime(n: Int) = {
val poly = pascal(n)
poly.slice(1, poly.length - 1).forall(i => i % n == 0)
}
for(i <- 0 to 7) { println( f"(x-1)^$i = ${poly2String( pascal(i) )}" ) }
val primes = (2 to 50).filter(isPrime)
println
println(primes mkString " ") |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref symbols nobinary
class RAnagramsV01 public
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method runSample(arg) public signals MalformedURLException, IOException
parse arg localFile .
isr = Reader
if localFile = '' then do
durl = URL("http://wiki.puzzlers.org/pub/wordlists/unixdict.txt")
dictFrom = durl.toString()
isr = InputStreamReader(durl.openStream())
end
else do
dictFrom = localFile
isr = FileReader(localFile)
end
say 'Searching' dictFrom 'for anagrams'
dictionaryReader = BufferedReader(isr)
anagrams = Map HashMap()
aWord = String
count = 0
loop label w_ forever
aWord = dictionaryReader.readLine()
if aWord = null then leave w_
chars = aWord.toCharArray()
Arrays.sort(chars)
key = String(chars)
if (\anagrams.containsKey(key)) then do
anagrams.put(key, ArrayList())
end
(ArrayList anagrams.get(key)).add(Object aWord)
count = Math.max(count, (ArrayList anagrams.get(key)).size())
end w_
dictionaryReader.close
ani = anagrams.values().iterator()
loop label a_ while ani.hasNext()
ana = ani.next()
if (ArrayList ana).size() >= count then do
say ana
end
end a_
return
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
method main(args = String[]) public static
arg = Rexx(args)
Do
ra = RAnagramsV01()
ra.runSample(arg)
Catch ex = Exception
ex.printStackTrace()
End
return
|
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #Wren | Wren | class Fibonacci {
static compute(n) {
var fib
fib = Fn.new {|n|
if (n < 2) return n
return fib.call(n - 1) + fib.call(n - 2)
}
if (n < 0) return null
return fib.call(n)
}
}
System.print(Fibonacci.compute(36)) |
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #Wren | Wren | import "/fmt" for Fmt
import "/math" for Int, Nums
var a = List.filled(20000, 0)
for (i in 1...20000) a[i] = Nums.sum(Int.properDivisors(i))
System.print("The amicable pairs below 20,000 are:")
for (n in 2...19999) {
var m = a[n]
if (m > n && m < 20000 && n == a[m]) {
System.print(" %(Fmt.d(5, n)) and %(Fmt.d(5, m))")
}
} |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a variable number of expressions (or values if that's simpler in the language) and yields a correct one which will satisfy a constraint in some future computation, thereby avoiding failure.
Problems whose solution the Amb operator naturally expresses can be approached with other tools, such as explicit nested iterations over data sets, or with pattern matching. By contrast, the Amb operator appears integrated into the language. Invocations of Amb are not wrapped in any visible loops or other search patterns; they appear to be independent.
Essentially Amb(x, y, z) splits the computation into three possible futures: a future in which the value x is yielded, a future in which the value y is yielded and a future in which the value z is yielded. The future which leads to a successful subsequent computation is chosen. The other "parallel universes" somehow go away. Amb called with no arguments fails.
For simplicity, one of the domain values usable with Amb may denote failure, if that is convenient. For instance, it is convenient if a Boolean false denotes failure, so that Amb(false) fails, and thus constraints can be expressed using Boolean expressions like Amb(x * y == 8) which unless x and y add to four.
A pseudo-code program which satisfies this constraint might look like:
let x = Amb(1, 2, 3)
let y = Amb(7, 6, 4, 5)
Amb(x * y = 8)
print x, y
The output is 2 4 because Amb(1, 2, 3) correctly chooses the future in which x has value 2, Amb(7, 6, 4, 5) chooses 4 and consequently Amb(x * y = 8) produces a success.
Alternatively, failure could be represented using strictly Amb():
unless x * y = 8 do Amb()
Or else Amb could take the form of two operators or functions: one for producing values and one for enforcing constraints:
let x = Ambsel(1, 2, 3)
let y = Ambsel(4, 5, 6)
Ambassert(x * y = 8)
print x, y
where Ambassert behaves like Amb() if the Boolean expression is false, otherwise it allows the future computation to take place, without yielding any value.
The task is to somehow implement Amb, and demonstrate it with a program which chooses one word from each of the following four sets of character strings to generate a four-word sentence:
"the" "that" "a"
"frog" "elephant" "thing"
"walked" "treaded" "grows"
"slowly" "quickly"
The constraint to be satisfied is that the last character of each word (other than the last) is the same as the first character of its successor.
The only successful sentence is "that thing grows slowly"; other combinations do not satisfy the constraint and thus fail.
The goal of this task isn't to simply process the four lists of words with explicit, deterministic program flow such as nested iteration, to trivially demonstrate the correct output. The goal is to implement the Amb operator, or a facsimile thereof that is possible within the language limitations.
| #Yabasic | Yabasic | sub wordsOK(string1$, string2$)
return right$(string1$, 1) == left$(string2$, 1)
End sub
sub Amb$(A$(), B$(), C$(), D$())
local a2, b2, c2, d2
For a2 = 1 To arraysize(A$(), 1)
For b2 = 1 To arraysize(B$(), 1)
For c2 = 1 To arraysize(C$(), 1)
For d2 = 1 To arraysize(D$(), 1)
If wordsOK(A$(a2), B$(b2)) And wordsOK(B$(b2), C$(c2)) And wordsOK(C$(c2), D$(d2)) Then
Return A$(a2) + " " + B$(b2) + " " + C$(c2) + " " + D$(d2)
End If
Next
Next
Next
Next
Return ""
End sub
Dim set1$(1), set2$(1), set3$(1), set4$(1)
void = token("the that a", set1$())
void = token("frog elephant thing", set2$())
void = token("walked treaded grows", set3$())
void = token("slowly quickly", set4$())
result$ = Amb$(set1$(), set2$(), set3$(), set4$())
If result$ <> "" Then
Print "Correct sentence would be: ", result$
Else
Print "Failed to fine a correct sentence."
End If |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a variable number of expressions (or values if that's simpler in the language) and yields a correct one which will satisfy a constraint in some future computation, thereby avoiding failure.
Problems whose solution the Amb operator naturally expresses can be approached with other tools, such as explicit nested iterations over data sets, or with pattern matching. By contrast, the Amb operator appears integrated into the language. Invocations of Amb are not wrapped in any visible loops or other search patterns; they appear to be independent.
Essentially Amb(x, y, z) splits the computation into three possible futures: a future in which the value x is yielded, a future in which the value y is yielded and a future in which the value z is yielded. The future which leads to a successful subsequent computation is chosen. The other "parallel universes" somehow go away. Amb called with no arguments fails.
For simplicity, one of the domain values usable with Amb may denote failure, if that is convenient. For instance, it is convenient if a Boolean false denotes failure, so that Amb(false) fails, and thus constraints can be expressed using Boolean expressions like Amb(x * y == 8) which unless x and y add to four.
A pseudo-code program which satisfies this constraint might look like:
let x = Amb(1, 2, 3)
let y = Amb(7, 6, 4, 5)
Amb(x * y = 8)
print x, y
The output is 2 4 because Amb(1, 2, 3) correctly chooses the future in which x has value 2, Amb(7, 6, 4, 5) chooses 4 and consequently Amb(x * y = 8) produces a success.
Alternatively, failure could be represented using strictly Amb():
unless x * y = 8 do Amb()
Or else Amb could take the form of two operators or functions: one for producing values and one for enforcing constraints:
let x = Ambsel(1, 2, 3)
let y = Ambsel(4, 5, 6)
Ambassert(x * y = 8)
print x, y
where Ambassert behaves like Amb() if the Boolean expression is false, otherwise it allows the future computation to take place, without yielding any value.
The task is to somehow implement Amb, and demonstrate it with a program which chooses one word from each of the following four sets of character strings to generate a four-word sentence:
"the" "that" "a"
"frog" "elephant" "thing"
"walked" "treaded" "grows"
"slowly" "quickly"
The constraint to be satisfied is that the last character of each word (other than the last) is the same as the first character of its successor.
The only successful sentence is "that thing grows slowly"; other combinations do not satisfy the constraint and thus fail.
The goal of this task isn't to simply process the four lists of words with explicit, deterministic program flow such as nested iteration, to trivially demonstrate the correct output. The goal is to implement the Amb operator, or a facsimile thereof that is possible within the language limitations.
| #zkl | zkl | fcn joins(a,b){ a[-1]==b[0] } // the constraint |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Retro | Retro | :acc (ns-)
d:create , [ [ fetch ] [ v:inc ] bi ] does ; |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #REXX | REXX | /*REXX program shows one method an accumulator factory could be implemented. */
x=.accumulator(1) /*initialize accumulator with a 1 value*/
x=call(5)
x=call(2.3)
say ' X value is now' x /*displays the current value of X. */
say 'Accumulator value is now' sum /*displays the current value of accum.*/
exit /*stick a fork in it, we're all done. */
/*──────────────────────────────────────────────────────────────────────────────────────*/
.accumulator: procedure expose sum; if symbol('SUM')=="LIT" then sum=0 /*1st time?*/
sum=sum + arg(1) /*add──►sum*/
return sum
/*──────────────────────────────────────────────────────────────────────────────────────*/
call: procedure expose sum; sum=sum+arg(1); return sum /*add arg1 ──► sum.*/ |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #Clojure | Clojure | (defn ackermann [m n]
(cond (zero? m) (inc n)
(zero? n) (ackermann (dec m) 1)
:else (ackermann (dec m) (ackermann m (dec n))))) |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #Groovy | Groovy | def dpaCalc = { factors ->
def n = factors.pop()
def fSum = factors.sum()
fSum < n
? 'deficient'
: fSum > n
? 'abundant'
: 'perfect'
}
(1..20000).inject([deficient:0, perfect:0, abundant:0]) { map, n ->
map[dpaCalc(factorize(n))]++
map
}
.each { e -> println e } |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Java | Java | import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.lang3.StringUtils;
/**
* Aligns fields into columns, separated by "|"
*/
public class ColumnAligner {
private List<String[]> words = new ArrayList<>();
private int columns = 0;
private List<Integer> columnWidths = new ArrayList<>();
/**
* Initialize columns aligner from lines in a single string
*
* @param s
* lines in a single string. Empty string does form a column.
*/
public ColumnAligner(String s) {
String[] lines = s.split("\\n");
for (String line : lines) {
processInputLine(line);
}
}
/**
* Initialize columns aligner from lines in a list of strings
*
* @param lines
* lines in a single string. Empty string does form a column.
*/
public ColumnAligner(List<String> lines) {
for (String line : lines) {
processInputLine(line);
}
}
private void processInputLine(String line) {
String[] lineWords = line.split("\\$");
words.add(lineWords);
columns = Math.max(columns, lineWords.length);
for (int i = 0; i < lineWords.length; i++) {
String word = lineWords[i];
if (i >= columnWidths.size()) {
columnWidths.add(word.length());
} else {
columnWidths.set(i, Math.max(columnWidths.get(i), word.length()));
}
}
}
interface AlignFunction {
String align(String s, int length);
}
/**
* Left-align all columns
*
* @return Lines, terminated by "\n" of columns, separated by "|"
*/
public String alignLeft() {
return align(new AlignFunction() {
@Override
public String align(String s, int length) {
return StringUtils.rightPad(s, length);
}
});
}
/**
* Right-align all columns
*
* @return Lines, terminated by "\n" of columns, separated by "|"
*/
public String alignRight() {
return align(new AlignFunction() {
@Override
public String align(String s, int length) {
return StringUtils.leftPad(s, length);
}
});
}
/**
* Center-align all columns
*
* @return Lines, terminated by "\n" of columns, separated by "|"
*/
public String alignCenter() {
return align(new AlignFunction() {
@Override
public String align(String s, int length) {
return StringUtils.center(s, length);
}
});
}
private String align(AlignFunction a) {
StringBuilder result = new StringBuilder();
for (String[] lineWords : words) {
for (int i = 0; i < lineWords.length; i++) {
String word = lineWords[i];
if (i == 0) {
result.append("|");
}
result.append(a.align(word, columnWidths.get(i)) + "|");
}
result.append("\n");
}
return result.toString();
}
public static void main(String args[]) throws IOException {
if (args.length < 1) {
System.out.println("Usage: ColumnAligner file [left|right|center]");
return;
}
String filePath = args[0];
String alignment = "left";
if (args.length >= 2) {
alignment = args[1];
}
ColumnAligner ca = new ColumnAligner(Files.readAllLines(Paths.get(filePath), StandardCharsets.UTF_8));
switch (alignment) {
case "left":
System.out.print(ca.alignLeft());
break;
case "right":
System.out.print(ca.alignRight());
break;
case "center":
System.out.print(ca.alignCenter());
break;
default:
System.err.println(String.format("Error! Unknown alignment: '%s'", alignment));
break;
}
}
} |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Scheme | Scheme |
;; implement mod m arithmetic with polnomials in x
;; as lists of coefficients, x^0 first.
;;
;; so x^3 + 5 is represented as (5 0 0 1)
(define (+/m m a b)
;; add two polynomials
(cond ((null? a) b)
((null? b) a)
(else (cons (modulo (+ (car a) (car b)) m)
(+/m m (cdr a) (cdr b))))))
(define (*c/m m c a)
;; multiplication by a constant
(map (lambda (v) (modulo (* c v) m)) a))
(define (*/m m a b)
;; multiply two polynomials
(let loop ((a a))
(if (null? a)
'()
(+/m m (*c/m m (car a) b)
(cons 0 (*/m m (cdr a) b))))))
(define (x^n/m m n)
(if (= n 0)
'(1)
(cons 0 (x^n/m m (- n 1)))))
(define (^n/m m a n)
;; calculate the n'th power of polynomial a
(cond ((= n 0) '(1))
((= n 1) a)
(else (*/m m a (^n/m m a (- n 1))))))
;; test case
;;
;; ? lift(Mod((x^3 + 5)*(4 + 3*x + x^2),6))
;; %13 = x^5 + 3*x^4 + 4*x^3 + 5*x^2 + 3*x + 2
;;
;; > (*/m 6 '(5 0 0 1) '(4 3 1))
;; '(2 3 5 4 3 1)
;;
;; working correctly
(define (rosetta-aks-test p)
(if (or (= p 0) (= p 1))
#f
;; u = (x - 1)^p
;; v = (x^p - 1)
(let ((u (^n/m p (list -1 1) p))
(v (+/m p (x^n/m p p) (list -1))))
(every zero? (+/m p u (*c/m p -1 v))))))
;; > (filter rosetta-aks-test (iota 50))
;; '(2 3 5 7 11 13 17 19 23 29 31 37 41 43 47)
|
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #NewLisp | NewLisp |
;;; Get the words as a list, splitting at newline
(setq data
(parse (get-url "http://wiki.puzzlers.org/pub/wordlists/unixdict.txt")
"\n"))
;
;;; Replace each word with a list of its key (list of sorted chars) and itself
;;; For example "hello" –> (("e" "h" "l" "l" "o") "hello")
(setq data (map (fn(x) (list (sort (explode x)) x)) data))
;
;;; Sort on the keys (data is modified); (x 0) is the same as (first x)
(sort data (fn(x y) (> (x 0)(y 0))))
;
;;; Return a list of lists of words with the same key
;;; An empty list at the head is inconsequential
(define (group-by-key)
(let (temp '() res '() oldkey '())
(dolist (x data)
(if (= (x 0) oldkey)
(push (x 1) temp)
(begin
(push temp res)
(setq temp (list (x 1)) oldkey (x 0)))))
(push temp res)
res))
;
;;; Print out only groups of more than 4 words
(map println (filter (fn(x) (> (length x) 4)) (group-by-key)))
|
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #x86_Assembly | x86 Assembly |
; Calculates and prints Fibonacci numbers (Fn)
; Prints numbers 1 - 47 (largest 32bit Fn that fits)
; Build:
; nasm -felf32 fib.asm
; ld -m elf32_i386 fib.o -o fib
global _start
section .text
_start:
mov ecx, 48 ; Initialize loop counter
.loop:
mov ebx, 48 ; Calculate which Fn will be computed
sub ebx, ecx ; Takes into account the reversed nature
push ebx ; Pass the parameter in on the stack
push .done ; Emulate a call but "return" to end of loop
; The return adress is manually set on the stack
; int fib (int n)
; Returns the n'th Fn
; fib(n) = 0 if n <= 0
; 1 if n == 1
; fib(n-1) + fib(n-2) otherwise
.fib:
push ebp ; Setup stack frame
mov ebp, esp
push ebx ; Save needed registers
xor eax, eax
mov ebx, [ebp + 8] ; Get the parameter
cmp ebx, 1 ; Test for base cases
jl .return
mov eax, 1
je .return
dec ebx ; Calculate fib(n-1)
push ebx
call .fib
mov [esp], eax ; Save result on top of parameter in stack
dec ebx ; Calculate fib(n-2)
push ebx
call .fib
add eax, [esp + 4] ; Add the first to the second
add esp, 8 ; Reset local stack
.return:
pop ebx ; Restore modified registers
mov esp, ebp ; Tear down stack frame and return
pop ebp
ret
.done:
mov [esp], ecx ; Save the counter between calls
push eax ; Print the number
call print_num
add esp, 4
pop ecx ; Restore the loop counter
loop .loop ; Loop until 0
mov eax, 0x01 ; sys_exit(int error)
xor ebx, ebx ; error = 0 (success)
int 0x80 ; syscall
; void print_num (int n)
; Prints an integer and newline
print_num:
push ebp
mov ebp, esp
sub esp, 11 ; Save space for digits and newline
lea ecx, [ebp - 1] ; Save a pointer to after the buffer
mov BYTE [ecx], 0x0A ; Set the newline at the end
mov eax, [ebp + 8] ; Get the parameter
mov ebx, DWORD 10 ; Divisor
.loop:
dec ecx ; Move pointer to next digit
xor edx, edx
div ebx ; Extract one digit, quot in eax, rem in edx
add dl, 0x30 ; Convert remainder to ascii
mov [ecx], dl ; Save the ascii form
cmp eax, 0 ; Loop until all digits have been converted
jg .loop
mov eax, 0x04 ; sys_write(int fd, char **buf, int len)
mov ebx, 1 ; stdout
mov edx, ebp ; Calculate the length
sub edx, ecx ; address after newline - address of first digit
int 0x80
mov esp, ebp
pop ebp
ret
|
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #XPL0 | XPL0 | func SumDiv(Num); \Return sum of proper divisors of Num
int Num, Div, Sum, Quot;
[Div:= 2;
Sum:= 0;
loop [Quot:= Num/Div;
if Div > Quot then quit;
if rem(0) = 0 then
[Sum:= Sum + Div;
if Div # Quot then Sum:= Sum + Quot;
];
Div:= Div+1;
];
return Sum+1;
];
def Limit = 20000;
int Tbl(Limit), N, M;
[for N:= 0 to Limit-1 do
Tbl(N):= SumDiv(N);
for N:= 1 to Limit-1 do
[M:= Tbl(N);
if M<Limit & N=Tbl(M) & M>N then
[IntOut(0, N); ChOut(0, 9\tab\);
IntOut(0, M); CrLf(0);
];
];
] |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Ring | Ring | oGenerator = new Generator
Func main
oGenerator {
accumulator = generator(1)
see call accumulator(5)
see nl
generator(3)
see call accumulator(2.3)
}
Class Generator
aN = []
func generator i
aN + i
return eval(substr("return func d {
oGenerator {
aN[#id#] += d
return aN[#id#]
}
}","#id#",string(len(aN)))) |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Ruby | Ruby | def accumulator(sum)
lambda {|n| sum += n}
end
# mixing Integer and Float
x = accumulator(1)
x.call(5)
accumulator(3)
puts x.call(2.3) # prints 8.3 |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #CLU | CLU | % Ackermann function
ack = proc (m, n: int) returns (int)
if m=0 then return(n+1)
elseif n=0 then return(ack(m-1, 1))
else return(ack(m-1, ack(m, n-1)))
end
end ack
% Print a table of ack( 0..3, 0..8 )
start_up = proc ()
po: stream := stream$primary_output()
for m: int in int$from_to(0, 3) do
for n: int in int$from_to(0, 8) do
stream$putright(po, int$unparse(ack(m,n)), 8)
end
stream$putl(po, "")
end
end start_up |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #Haskell | Haskell | divisors :: (Integral a) => a -> [a]
divisors n = filter ((0 ==) . (n `mod`)) [1 .. (n `div` 2)]
classOf :: (Integral a) => a -> Ordering
classOf n = compare (sum $ divisors n) n
main :: IO ()
main = do
let classes = map classOf [1 .. 20000 :: Int]
printRes w c = putStrLn $ w ++ (show . length $ filter (== c) classes)
printRes "deficient: " LT
printRes "perfect: " EQ
printRes "abundant: " GT |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #JavaScript | JavaScript |
var justification="center",
input=["Given$a$text$file$of$many$lines,$where$fields$within$a$line$",
"are$delineated$by$a$single$'dollar'$character,$write$a$program",
"that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$",
"column$are$separated$by$at$least$one$space.",
"Further,$allow$for$each$word$in$a$column$to$be$either$left$",
"justified,$right$justified,$or$center$justified$within$its$column."],
x,y,cols,max,cols=0,diff,left,right
String.prototype.repeat=function(n){return new Array(1 + parseInt(n)).join(this);}
for(x=0;x<input.length;x++) {
input[x]=input[x].split("$");
if(input[x].length>cols) cols=input[x].length;
}
for(x=0;x<cols;x++) {
max=0;
for(y=0;y<input.length;y++) if(input[y][x]&&max<input[y][x].length) max=input[y][x].length;
for(y=0;y<input.length;y++)
if(input[y][x]) {
diff=(max-input[y][x].length)/2;
left=" ".repeat(Math.floor(diff));
right=" ".repeat(Math.ceil(diff));
if(justification=="left") {right+=left;left=""}
if(justification=="right") {left+=right;right=""}
input[y][x]=left+input[y][x]+right;
}
}
for(x=0;x<input.length;x++) input[x]=input[x].join(" ");
input=input.join("\n");
document.write(input); |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Scilab | Scilab |
clear
xdel(winsid())
stacksize('max')
sz=stacksize();
n=7; //For the expansion up to power of n
g=50; //For test of primes up to g
function X = pascal(g) //Pascal´s triangle
X(1,1)=1; //Zeroth power
X(2,1)=1; //First power
X(2,2)=1;
for q=3:1:g+1 //From second power use this loop
X(q,1)=1;
X(q,q)=1;
for p=2:1:q-1
X(q,p)=X(q-1,p-1)+X(q-1,p);
end
end
endfunction
Z=pascal(g); //Generate Pascal's triangle up to g
Q(0+1)="(x-1)^0 = 1"; //For nicer display
Q(1+1)="(x-1)^1 = x^1-1"; //For nicer display
disp(Q(1))
disp(Q(2))
function cf=coef(Z,q,p) //Return coeffiecents for nicer display of expansion without "ones"
if Z(q,p)==1 then
cf="";
else
cf=string(Z(q,p));
end
endfunction
for q=3:n+1 //Generate and display the expansions
Q(q)=strcat(["(x-1)^",string(q-1)," = "]);
sing=""; //Sign of coeff.
for p=1:q-1 //Number of coefficients equals power minus 1
Q(q)=strcat([Q(q),sing,coef(Z,q,p),"x^",string(q-p)]);
if sing=="-" then sing="+"; else sing="-"; end
end
Q(q)=strcat([Q(q),sing,string(1)]);
disp(Q(q))
clear Q
end
function prime=prime(Z,g)
prime="true";
for p=2:g
if abs(floor(Z(g+1,p)/g)-Z(g+1,p)/g)>0 then
prime="false";
break;
end
end
endfunction
R="2"; //For nicer display
for r=3:g
if prime(Z,r)=="true" then
R=strcat([R, ", ",string(r)]);
end
end
disp(R)
|
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Seed7 | Seed7 | $ include "seed7_05.s7i";
const func array integer: expand_x_1 (in integer: p) is func
result
var array integer: ex is [] (1);
local
var integer: i is 0;
begin
for i range 0 to p - 1 do
ex := [] (ex[1] * -(p - i) div (i + 1)) & ex;
end for;
end func;
const func boolean: aks_test (in integer: p) is func
result
var boolean: aks_test is FALSE;
local
var array integer: ex is 0 times 0;
var integer: idx is 0;
begin
if p >= 2 then
ex := expand_x_1(p);
ex[1] +:= 1;
for idx range 1 to pred(length(ex)) until ex[idx] rem p <> 0 do
noop;
end for;
aks_test := idx = length(ex);
end if;
end func;
const proc: main is func
local
var integer: p is 0;
var integer: n is 0;
var integer: e is 0;
begin
writeln("# p: (x-1)^p for small p");
for p range 0 to 11 do
write(p lpad 3 <& ": ");
for n key e range expand_x_1(p) do
write(" ");
if n >= 0 then
write("+");
end if;
write(n);
if e > 1 then
write("x^" <& pred(e));
end if;
end for;
writeln;
end for;
writeln;
writeln("# small primes using the aks test");
for p range 0 to 61 do
if aks_test(p) then
write(p <& " ");
end if;
end for;
writeln;
end func; |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Nim | Nim |
import tables, strutils, algorithm
proc main() =
var
count = 0
anagrams = initTable[string, seq[string]]()
for word in "unixdict.txt".lines():
var key = word
key.sort(cmp[char])
anagrams.mgetOrPut(key, newSeq[string]()).add(word)
count = max(count, anagrams[key].len)
for _, v in anagrams:
if v.len == count:
v.join(" ").echo
main()
|
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #XPL0 | XPL0 | include c:\cxpl\codes;
func Fib(X);
int X;
func ActualFib(N);
int N;
[if N<2 then return N
else return ActualFib(N-1) + ActualFib(N-2);
]; \ActualFib;
[if X<0 then [Text(0, "Error "); return 0]
else return ActualFib(X);
]; \Fib;
[IntOut(0, Fib(8)); CrLf(0);
IntOut(0, Fib(-2)); CrLf(0);
] |
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #Yabasic | Yabasic | sub sumDivs(n)
local sum, d
sum = 1
for d = 2 to sqrt(n)
if not mod(n, d) then
sum = sum + d
sum = sum + n / d
end if
next
return sum
end sub
for n = 2 to 20000
m = sumDivs(n)
if m > n then
if sumDivs(m) = n print n, "\t", m
end if
next
print : print peek("millisrunning"), " ms" |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Rust | Rust | // rustc 1.26.0 or later
use std::ops::Add;
fn foo<Num>(n: Num) -> impl FnMut(Num) -> Num
where Num: Add<Output=Num> + Copy + 'static {
let mut acc = n;
move |i: Num| {
acc = acc + i;
acc
}
}
fn main() {
let mut x = foo(1.);
x(5.);
foo(3.);
println!("{}", x(2.3));
} |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Scala | Scala | def AccumulatorFactory[N](n: N)(implicit num: Numeric[N]) = {
import num._
var acc = n
(inc: N) => {
acc = acc + inc
acc
}
} |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #COBOL | COBOL | IDENTIFICATION DIVISION.
PROGRAM-ID. Ackermann.
DATA DIVISION.
LINKAGE SECTION.
01 M USAGE UNSIGNED-LONG.
01 N USAGE UNSIGNED-LONG.
01 Return-Val USAGE UNSIGNED-LONG.
PROCEDURE DIVISION USING M N Return-Val.
EVALUATE M ALSO N
WHEN 0 ALSO ANY
ADD 1 TO N GIVING Return-Val
WHEN NOT 0 ALSO 0
SUBTRACT 1 FROM M
CALL "Ackermann" USING BY CONTENT M BY CONTENT 1
BY REFERENCE Return-Val
WHEN NOT 0 ALSO NOT 0
SUBTRACT 1 FROM N
CALL "Ackermann" USING BY CONTENT M BY CONTENT N
BY REFERENCE Return-Val
SUBTRACT 1 FROM M
CALL "Ackermann" USING BY CONTENT M
BY CONTENT Return-Val BY REFERENCE Return-Val
END-EVALUATE
GOBACK
. |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #J | J | factors=: [: /:~@, */&>@{@((^ i.@>:)&.>/)@q:~&__
properDivisors=: factors -. ] |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #jq | jq | # transpose a possibly jagged matrix
def transpose:
if . == [] then []
else (.[1:] | transpose) as $t
| .[0] as $row
| reduce range(0; [($t|length), (.[0]|length)] | max) as $i
([]; . + [ [ $row[$i] ] + $t[$i] ])
end;
# left/right/center justification of strings:
def ljust(width): . + " " * (width - length);
def rjust(width): " " * (width - length) + .;
def center(width):
(width - length) as $pad
| if $pad <= 0 then .
else ($pad / 2 | floor) as $half
| $half * " " + . + ($pad-$half) * " "
end ;
# input: a single string, which includes newlines to separate lines, and $ to separate phrases;
# method must be "left" "right" or anything else for central justification.
def format(method):
def justify(width):
if method == "left" then ljust(width)
elif method == "right" then rjust(width)
else center(width)
end;
# max_widths: input: an array of strings, each with "$" as phrase-separator;
# return the appropriate column-wise maximum lengths
def max_widths:
map(split("$") | map(length))
| transpose | map(max) ;
split("\n") as $input
| $input
| (max_widths | map(.+1)) as $widths
| map( split("$") | . as $line | reduce range(0; length) as $i
(""; . + ($line[$i]|justify($widths[$i])) ))
| join("\n")
; |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Sidef | Sidef | func binprime(p) {
p >= 2 || return false
for i in (1 .. p>>1) {
(binomial(p, i) % p) && return false
}
return true
}
func coef(n, e) {
(e == 0) && return "#{n}"
(n == 1) && (n = "")
(e == 1) ? "#{n}x" : "#{n}x^#{e}"
}
func binpoly(p) {
join(" ", coef(1, p), ^p -> map {|i|
join(" ", %w(+ -)[(p-i)&1], coef(binomial(p, i), i))
}.reverse...)
}
say "expansions of (x-1)^p:"
for i in ^10 { say binpoly(i) }
say "Primes to 80: [#{2..80 -> grep { binprime(_) }.join(' ')}]" |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Oberon-2 | Oberon-2 |
MODULE Anagrams;
IMPORT Files,Out,In,Strings;
CONST
MAXPOOLSZ = 1024;
TYPE
String = ARRAY 80 OF CHAR;
Node = POINTER TO NodeDesc;
NodeDesc = RECORD;
count: INTEGER;
word: String;
desc: Node;
next: Node;
END;
Pool = POINTER TO PoolDesc;
PoolDesc = RECORD
capacity,max: INTEGER;
words: POINTER TO ARRAY OF Node;
END;
PROCEDURE InitNode(n: Node);
BEGIN
n^.count := 0;
n^.word := "";
n^.desc := NIL;
n^.next := NIL;
END InitNode;
PROCEDURE Index(s: ARRAY OF CHAR;cap: INTEGER): INTEGER;
VAR
i,sum: INTEGER;
BEGIN
sum := 0;
FOR i := 0 TO Strings.Length(s) DO
INC(sum,ORD(s[i]))
END;
RETURN sum MOD cap
END Index;
PROCEDURE ISort(VAR s: ARRAY OF CHAR);
VAR
i, j: INTEGER;
t: CHAR;
BEGIN
FOR i := 0 TO Strings.Length(s) - 1 DO
j := i;
t := s[j];
WHILE (j > 0) & (s[j -1] > t) DO
s[j] := s[j - 1];
DEC(j)
END;
s[j] := t
END
END ISort;
PROCEDURE SameLetters(x,y: ARRAY OF CHAR): BOOLEAN;
BEGIN
ISort(x);ISort(y);
RETURN (Strings.Compare(x,y) = 0)
END SameLetters;
PROCEDURE InitPool(p:Pool);
BEGIN
InitPoolWith(p,MAXPOOLSZ);
END InitPool;
PROCEDURE InitPoolWith(p:Pool;cap: INTEGER);
VAR
i: INTEGER;
BEGIN
p^.capacity := cap;
p^.max := 0;
NEW(p^.words,cap);
i := 0;
WHILE i < p^.capacity DO
p^.words^[i] := NIL;
INC(i);
END;
END InitPoolWith;
PROCEDURE (p: Pool) Add(w: ARRAY OF CHAR);
VAR
idx: INTEGER;
iter,n: Node;
BEGIN
idx := Index(w,p^.capacity);
iter := p^.words^[idx];
NEW(n);InitNode(n);COPY(w,n^.word);
WHILE(iter # NIL) DO
IF SameLetters(w,iter^.word) THEN
INC(iter^.count);
IF iter^.count > p^.max THEN p^.max := iter^.count END;
n^.desc := iter^.desc;
iter^.desc := n;
RETURN
END;
iter := iter^.next
END;
ASSERT(iter = NIL);
n^.next := p^.words^[idx];p^.words^[idx] := n
END Add;
PROCEDURE ShowAnagrams(l: Node);
VAR
iter: Node;
BEGIN
iter := l;
WHILE iter # NIL DO
Out.String(iter^.word);Out.String(" ");
iter := iter^.desc
END;
Out.Ln
END ShowAnagrams;
PROCEDURE (p: Pool) ShowMax();
VAR
i: INTEGER;
iter: Node;
BEGIN
FOR i := 0 TO LEN(p^.words^) - 1 DO
IF p^.words^[i] # NIL THEN
iter := p^.words^[i];
WHILE iter # NIL DO
IF iter^.count = p^.max THEN
ShowAnagrams(iter);
END;
iter := iter^.next
END
END
END
END ShowMax;
PROCEDURE DoProcess(fnm: ARRAY OF CHAR);
VAR
stdinBck,istream: Files.File;
line: String;
p: Pool;
BEGIN
istream := Files.Open(fnm,"r");
stdinBck := Files.stdin;
Files.stdin := istream;
NEW(p);InitPool(p);
WHILE In.Done DO
In.Line(line);
p.Add(line);
END;
Files.stdin := stdinBck;
Files.Close(istream);
p^.ShowMax();
END DoProcess;
BEGIN
DoProcess("unixdict.txt");
END Anagrams.
|
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #Yabasic | Yabasic | print Fibonacci(-10)
print Fibonacci(10)
sub Fibonacci(number)
If number < 0 print "Invalid argument: "; : return number
If number < 2 Then
Return number
Else
Return Fibonacci(number - 1) + Fibonacci(number - 2)
EndIf
end sub |
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #zkl | zkl | fcn properDivs(n){ [1.. (n + 1)/2 + 1].filter('wrap(x){ n%x==0 and n!=x }) }
const N=20000;
sums:=[1..N].pump(T(-1),fcn(n){ properDivs(n).sum(0) });
[0..].zip(sums).filter('wrap([(n,s)]){ (n<s<=N) and sums[s]==n }).println(); |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Scheme | Scheme | (define (accumulator sum)
(lambda (n)
(set! sum (+ sum n))
sum))
;; or:
(define ((accumulator sum) n)
(set! sum (+ sum n))
sum)
(define x (accumulator 1))
(x 5)
(display (accumulator 3)) (newline)
(display (x 2.3)) (newline) |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Sidef | Sidef | class Accumulator(sum) {
method add(num) {
sum += num;
}
}
var x = Accumulator(1);
x.add(5);
Accumulator(3);
say x.add(2.3); # prints: 8.3 |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #CoffeeScript | CoffeeScript | ackermann = (m, n) ->
if m is 0 then n + 1
else if m > 0 and n is 0 then ackermann m - 1, 1
else ackermann m - 1, ackermann m, n - 1 |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #Java | Java | import java.util.stream.LongStream;
public class NumberClassifications {
public static void main(String[] args) {
int deficient = 0;
int perfect = 0;
int abundant = 0;
for (long i = 1; i <= 20_000; i++) {
long sum = properDivsSum(i);
if (sum < i)
deficient++;
else if (sum == i)
perfect++;
else
abundant++;
}
System.out.println("Deficient: " + deficient);
System.out.println("Perfect: " + perfect);
System.out.println("Abundant: " + abundant);
}
public static long properDivsSum(long n) {
return LongStream.rangeClosed(1, (n + 1) / 2).filter(i -> n != i && n % i == 0).sum();
}
} |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Jsish | Jsish | /* Align columns, in Jsish */
function alignColumns(phrases:array, just:string) {
var x, y, max, diff, left, right, cols=0;
for(x=0; x<phrases.length; x++) {
phrases[x] = phrases[x].split("$");
if (phrases[x].length>cols) cols=phrases[x].length;
}
for (x=0; x<cols; x++) {
max = 0;
for (y=0; y<phrases.length; y++) if (phrases[y][x] && max<phrases[y][x].length) max = phrases[y][x].length;
for (y=0; y<phrases.length; y++) {
if (phrases[y][x]) {
diff = (max-phrases[y][x].length)/2;
left = " ".repeat(Math.floor(diff));
right = " ".repeat(Math.ceil(diff));
if (just == "left") { right += left; left=""; }
if (just == "right") { left += right; right=""; }
phrases[y][x] = left + phrases[y][x] + right;
}
}
}
for (x=0; x<phrases.length; x++) phrases[x] = phrases[x].join(" ");
phrases = phrases.join("\n");
return phrases;
}
if (Interp.conf('unitTest')) {
var phrases = ["Given$a$text$file$of$many$lines,$where$fields$within$a$line$",
"are$delineated$by$a$single$'dollar'$character,$write$a$program",
"that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$",
"column$are$separated$by$at$least$one$space.",
"Further,$allow$for$each$word$in$a$column$to$be$either$left$",
"justified,$right$justified,$or$center$justified$within$its$column."];
for (var just of ['left', 'center', 'right']) {
var trial = phrases.slice(0);
puts(just);
puts(alignColumns(trial, just), '\n');
}
} |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Stata | Stata | mata
function pol(n) {
a=J(1,n+1,1)
r=1
s=1
for (k=0; k<n; k++) {
s=-s
r=(r*(n-k))/(k+1)
a[k+2]=r*s
}
return(a)
}
for (n=0; n<=7; n++) mm_matlist(pol(n))
1
+-------------+
1 | 1 |
+-------------+
1 2
+-------------------------+
1 | 1 -1 |
+-------------------------+
1 2 3
+-------------------------------------+
1 | 1 -2 1 |
+-------------------------------------+
1 2 3 4
+-------------------------------------------------+
1 | 1 -3 3 -1 |
+-------------------------------------------------+
1 2 3 4 5
+-------------------------------------------------------------+
1 | 1 -4 6 -4 1 |
+-------------------------------------------------------------+
1 2 3 4 5 6
+-------------------------------------------------------------------------+
1 | 1 -5 10 -10 5 -1 |
+-------------------------------------------------------------------------+
1 2 3 4 5 6 7
+-------------------------------------------------------------------------------------+
1 | 1 -6 15 -20 15 -6 1 |
+-------------------------------------------------------------------------------------+
1 2 3 4 5 6 7 8
+-------------------------------------------------------------------------------------------------+
1 | 1 -7 21 -35 35 -21 7 -1 |
+-------------------------------------------------------------------------------------------------+
function isprime(n) {
a=pol(n)
for (k=2; k<=n; k++) {
if (mod(a[k],n)) return(0)
}
return(1)
}
for (n=2; n<=50; n++) {
if (isprime(n)) printf("%f ",n)
}
2 3 5 7 11 13 17 19 23 29 31 37 41 43 47
end |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Swift | Swift | func polynomialCoeffs(n: Int) -> [Int] {
var result = [Int](count : n+1, repeatedValue : 0)
result[0]=1
for i in 1 ..< n/2+1 { //Progress up, until reaching the middle value
result[i] = result[i-1] * (n-i+1)/i;
}
for i in n/2+1 ..< n+1 { //Copy the inverse of the first part
result[i] = result[n-i];
}
// Take into account the sign
for i in stride(from: 1, through: n, by: 2) {
result[i] = -result[i]
}
return result
}
func isPrime(n: Int) -> Bool {
var coeffs = polynomialCoeffs(n)
coeffs[0]--
coeffs[n]++
for i in 1 ... n {
if coeffs[i]%n != 0 {
return false
}
}
return true
}
for i in 0...10 {
let coeffs = polynomialCoeffs(i)
print("(x-1)^\(i) = ")
if i == 0 {
print("1")
} else {
if i == 1 {
print("x")
} else {
print("x^\(i)")
if i == 2 {
print("\(coeffs[i-1])x")
} else {
for j in 1...(i - 2) {
if j%2 == 0 {
print("+\(coeffs[j])x^\(i-j)")
} else {
print("\(coeffs[j])x^\(i-j)")
}
}
if (i-1)%2 == 0 {
print("+\(coeffs[i-1])x")
} else {
print("\(coeffs[i-1])x")
}
}
}
if i%2 == 0 {
print("+\(coeffs[i])")
} else {
print("\(coeffs[i])")
}
}
println()
}
println()
print("Primes under 50 : ")
for i in 1...50 {
if isPrime(i) {
print("\(i) ")
}
}
|
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Objeck | Objeck | use HTTP;
use Collection;
class Anagrams {
function : Main(args : String[]) ~ Nil {
lines := HttpClient->New()->Get("http://wiki.puzzlers.org/pub/wordlists/unixdict.txt");
anagrams := StringMap->New();
count := 0;
if(lines->Size() = 1) {
line := lines->Get(0)->As(String);
words := line->Split("\n");
each(i : words) {
word := words[i]->Trim();
key := String->New(word->ToCharArray()->Sort());
list := anagrams->Find(key)->As(Vector);
if(list = Nil) {
list := Vector->New();
anagrams->Insert(key, list);
};
list->AddBack(word);
count := count->Max(list->Size());
};
lists := anagrams->GetValues();
each(i : lists) {
list := lists->Get(i)->As(Vector);
if(list->Size() >= count) {
'['->Print();
each(j : list) {
list->Get(j)->As(String)->Print();
if(j + 1 < list->Size()) {
','->Print();
};
};
']'->PrintLine();
};
};
};
}
}
|
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #zkl | zkl | fcn fib(n){
if (n<0) throw(Exception.ValueError);
fcn(n){
if (n < 2) return(1);
else return(self.fcn(n-1) + self.fcn(n-2));
}(n);
}
fib(8) .println();
fib(-8).println();
|
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #Zig | Zig | const MAXIMUM: u32 = 20_000;
// Fill up a given array with arr[n] = sum(propDivs(n))
pub fn calcPropDivs(divs: []u32) void {
for (divs) |*d| d.* = 1;
var i: u32 = 2;
while (i <= divs.len/2) : (i += 1) {
var j = i * 2;
while (j < divs.len) : (j += i)
divs[j] += i;
}
}
// Are (A, B) an amicable pair?
pub fn amicable(divs: []const u32, a: u32, b: u32) bool {
return divs[a] == b and a == divs[b];
}
pub fn main() !void {
const stdout = @import("std").io.getStdOut().writer();
var divs: [MAXIMUM + 1]u32 = undefined;
calcPropDivs(divs[0..]);
var a: u32 = 1;
while (a < divs.len) : (a += 1) {
var b = a+1;
while (b < divs.len) : (b += 1) {
if (amicable(divs[0..], a, b))
try stdout.print("{d}, {d}\n", .{a, b});
}
}
} |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Simula | Simula | BEGIN
! ABSTRACTION FOR SIMULA'S TWO NUMERIC TYPES ;
CLASS NUMBER;
VIRTUAL:
PROCEDURE OUT IS PROCEDURE OUT;;
BEGIN
END NUMBER;
NUMBER CLASS INTEGERNUMBER(INTVAL); INTEGER INTVAL;
BEGIN
PROCEDURE OUT; OUTINT(INTVAL, 10);
END INTEGERNUMBER;
NUMBER CLASS REALNUMBER(REALVAL); REAL REALVAL;
BEGIN
PROCEDURE OUT; OUTFIX(REALVAL, 4, 10);
END REALNUMBER;
! SIMULA CANNOT RETURN FUNCTIONS - SIMULATE FUNCTIONS WITH CLASSES ;
CLASS ACCUMULATOR(ACC); REF(NUMBER) ACC;
BEGIN
PROCEDURE SWITCHTOREAL(Y); REAL Y;
BEGIN
REF(REALNUMBER) NEWACC;
NEWACC :- NEW REALNUMBER(ACC QUA INTEGERNUMBER.INTVAL);
NEWACC.REALVAL:= NEWACC.REALVAL + Y;
ACC :- NEWACC;
END SWITCHTOREAL;
REF(NUMBER) PROCEDURE ACCUMULATE(OTHERNUM); REF(NUMBER) OTHERNUM;
BEGIN
INSPECT ACC
WHEN INTEGERNUMBER DO
BEGIN
INSPECT OTHERNUM
WHEN INTEGERNUMBER DO
ACC QUA INTEGERNUMBER.INTVAL
:= ACC QUA INTEGERNUMBER.INTVAL + INTVAL
WHEN REALNUMBER DO
SWITCHTOREAL(REALVAL)
END
WHEN REALNUMBER DO
BEGIN
INSPECT OTHERNUM
WHEN INTEGERNUMBER DO
ACC QUA REALNUMBER.REALVAL
:= ACC QUA REALNUMBER.REALVAL + INTVAL
WHEN REALNUMBER DO
ACC QUA REALNUMBER.REALVAL
:= ACC QUA REALNUMBER.REALVAL + REALVAL
END;
ACCUMULATE :- ACC;
END ACCUMULATE;
PROCEDURE OUT; ACC.OUT;
END FOO;
REF(ACCUMULATOR) FOO;
FOO :- NEW ACCUMULATOR(NEW INTEGERNUMBER(1)); FOO.OUT; OUTIMAGE;
FOO.ACCUMULATE(NEW INTEGERNUMBER(5)); FOO.OUT; OUTIMAGE;
NEW ACCUMULATOR(NEW INTEGERNUMBER(3));
FOO.ACCUMULATE(NEW REALNUMBER(2.3)); FOO.OUT; OUTIMAGE;
END.
|
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Smalltalk | Smalltalk | Object subclass: AccumulatorFactory [
AccumulatorFactory class >> new: aNumber [
|r sum|
sum := aNumber.
r := [ :a |
sum := sum + a.
sum
].
^r
]
]
|x y|
x := AccumulatorFactory new: 1.
x value: 5.
y := AccumulatorFactory new: 3.
(x value: 2.3) displayNl.
"x inspect."
"de-comment the previous line to show that x is a block closure" |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #Comal | Comal | 0010 //
0020 // Ackermann function
0030 //
0040 FUNC a#(m#,n#)
0050 IF m#=0 THEN RETURN n#+1
0060 IF n#=0 THEN RETURN a#(m#-1,1)
0070 RETURN a#(m#-1,a#(m#,n#-1))
0080 ENDFUNC a#
0090 //
0100 // Print table of Ackermann values
0110 //
0120 ZONE 5
0130 FOR m#:=0 TO 3 DO
0140 FOR n#:=0 TO 4 DO PRINT a#(m#,n#),
0150 PRINT
0160 ENDFOR m#
0170 END |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #JavaScript | JavaScript | for (var dpa=[1,0,0], n=2; n<=20000; n+=1) {
for (var ds=0, d=1, e=n/2+1; d<e; d+=1) if (n%d==0) ds+=d
dpa[ds<n ? 0 : ds==n ? 1 : 2]+=1
}
document.write('Deficient:',dpa[0], ', Perfect:',dpa[1], ', Abundant:',dpa[2], '<br>' ) |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Julia | Julia | txt = """Given\$a\$txt\$file\$of\$many\$lines,\$where\$fields\$within\$a\$line\$
are\$delineated\$by\$a\$single\$'dollar'\$character,\$write\$a\$program
that\$aligns\$each\$column\$of\$fields\$by\$ensuring\$that\$words\$in\$each\$
column\$are\$separated\$by\$at\$least\$one\$space.
Further,\$allow\$for\$each\$word\$in\$a\$column\$to\$be\$either\$left\$
justified,\$right\$justified,\$or\$center\$justified\$within\$its\$column."""
# left/right/center justification of strings:
ljust(s, width) = s * " "^max(0, width - length(s))
rjust(s, width) = " "^max(0, width - length(s)) * s
function center(s, width)
pad = width - length(s)
if pad <= 0
return s
else
pad2 = div(pad, 2)
return " "^pad2 * s * " "^(pad - pad2)
end
end
parts = [split(rstrip(line, '$'), '$') for line in split(txt, '\n')]
max_widths = zeros(Int, maximum(length, parts))
for line in parts
for (i, word) in enumerate(line)
max_widths[i] = max(max_widths[i], length(word))
end
end
max_widths += 1 # separate cols by at least one space
for (label, justify) in (("Left", ljust), ("Right",rjust), ("Center",center))
println(label, " column-aligned output:")
for line in parts
for (j, word) in enumerate(line)
print(justify(word, max_widths[j]))
end
println()
end
println("-"^sum(max_widths))
end |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Tcl | Tcl | proc coeffs {p {signs 1}} {
set clist 1
for {set i 0} {$i < $p} {incr i} {
set clist [lmap x [list 0 {*}$clist] y [list {*}$clist 0] {
expr {$x + $y}
}]
}
if {$signs} {
set s -1
set clist [lmap c $clist {expr {[set s [expr {-$s}]] * $c}}]
}
return $clist
}
proc aksprime {p} {
if {$p < 2} {
return false
}
foreach c [coeffs $p 0] {
if {$c == 1} continue
if {$c % $p} {
return false
}
}
return true
}
for {set i 0} {$i <= 7} {incr i} {
puts -nonewline "(x-1)^$i ="
set j $i
foreach c [coeffs $i] {
puts -nonewline [format " %+dx^%d" $c $j]
incr j -1
}
puts ""
}
set sub35primes {}
for {set i 1} {$i < 35} {incr i} {
if {[aksprime $i]} {
lappend sub35primes $i
}
}
puts "primes under 35: [join $sub35primes ,]"
set sub50primes {}
for {set i 1} {$i < 50} {incr i} {
if {[aksprime $i]} {
lappend sub50primes $i
}
}
puts "primes under 50: [join $sub50primes ,]" |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #OCaml | OCaml | let explode str =
let l = ref [] in
let n = String.length str in
for i = n - 1 downto 0 do
l := str.[i] :: !l
done;
(!l)
let implode li =
let n = List.length li in
let s = String.create n in
let i = ref 0 in
List.iter (fun c -> s.[!i] <- c; incr i) li;
(s)
let () =
let h = Hashtbl.create 3571 in
let ic = open_in "unixdict.txt" in
try while true do
let w = input_line ic in
let k = implode (List.sort compare (explode w)) in
let l =
try Hashtbl.find h k
with Not_found -> []
in
Hashtbl.replace h k (w::l);
done with End_of_file -> ();
let n = Hashtbl.fold (fun _ lw n -> max n (List.length lw)) h 0 in
Hashtbl.iter (fun _ lw ->
if List.length lw >= n then
( List.iter (Printf.printf " %s") lw;
print_newline () )
) h |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the function doesn't have the right arguments and/or return values.
So we end up inventing some silly name like foo2 or foo_helper. I have always found it painful to come up with a proper name, and see some disadvantages:
You have to think up a name, which then pollutes the namespace
Function is created which is called from nowhere else
The program flow in the source code is interrupted
Some languages allow you to embed recursion directly in-place. This might work via a label, a local gosub instruction, or some special keyword.
Anonymous recursion can also be accomplished using the Y combinator.
Task
If possible, demonstrate this by writing the recursive version of the fibonacci function (see Fibonacci sequence) which checks for a negative argument before doing the actual recursion.
| #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 INPUT "Enter a number: ";n
20 LET t=0
30 GO SUB 60
40 PRINT t
50 STOP
60 LET nold1=1: LET nold2=0
70 IF n<0 THEN PRINT "Positive argument required!": RETURN
80 IF n=0 THEN LET t=nold2: RETURN
90 IF n=1 THEN LET t=nold1: RETURN
100 LET t=nold2+nold1
110 IF n>2 THEN LET n=n-1: LET nold2=nold1: LET nold1=t: GO SUB 100
120 RETURN
|
http://rosettacode.org/wiki/Amicable_pairs | Amicable pairs | Two integers
N
{\displaystyle N}
and
M
{\displaystyle M}
are said to be amicable pairs if
N
≠
M
{\displaystyle N\neq M}
and the sum of the proper divisors of
N
{\displaystyle N}
(
s
u
m
(
p
r
o
p
D
i
v
s
(
N
)
)
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))}
)
=
M
{\displaystyle =M}
as well as
s
u
m
(
p
r
o
p
D
i
v
s
(
M
)
)
=
N
{\displaystyle \mathrm {sum} (\mathrm {propDivs} (M))=N}
.
Example
1184 and 1210 are an amicable pair, with proper divisors:
1, 2, 4, 8, 16, 32, 37, 74, 148, 296, 592 and
1, 2, 5, 10, 11, 22, 55, 110, 121, 242, 605 respectively.
Task
Calculate and show here the Amicable pairs below 20,000; (there are eight).
Related tasks
Proper divisors
Abundant, deficient and perfect number classifications
Aliquot sequence classifications and its amicable classification.
| #ZX_Spectrum_Basic | ZX Spectrum Basic | 10 LET limit=20000
20 PRINT "Amicable pairs < ";limit
30 FOR n=1 TO limit
40 LET num=n: GO SUB 1000
50 LET m=num
60 GO SUB 1000
70 IF n=num AND n<m THEN PRINT n;" ";m
80 NEXT n
90 STOP
1000 REM sumprop
1010 IF num<2 THEN LET num=0: RETURN
1020 LET sum=1
1030 LET root=SQR num
1040 FOR i=2 TO root-.01
1050 IF num/i=INT (num/i) THEN LET sum=sum+i+num/i
1060 NEXT i
1070 IF num/root=INT (num/root) THEN LET sum=sum+root
1080 LET num=sum
1090 RETURN |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Standard_ML | Standard ML | fun accumulator (sum0:real) : real -> real = let
val sum = ref sum0
in
fn n => (
sum := !sum + n;
!sum)
end;
let
val x = accumulator 1.0
val _ = x 5.0
val _ = accumulator 3.0
in
print (Real.toString (x 2.3) ^ "\n")
end; |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Swift | Swift | func makeAccumulator(var sum: Double) -> Double -> Double {
return {
sum += $0
return sum
}
}
let x = makeAccumulator(1)
x(5)
let _ = makeAccumulator(3)
println(x(2.3)) |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #Common_Lisp | Common Lisp | (defun ackermann (m n)
(cond ((zerop m) (1+ n))
((zerop n) (ackermann (1- m) 1))
(t (ackermann (1- m) (ackermann m (1- n)))))) |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #jq | jq | # unordered
def proper_divisors:
. as $n
| if $n > 1 then 1,
( range(2; 1 + (sqrt|floor)) as $i
| if ($n % $i) == 0 then $i,
(($n / $i) | if . == $i then empty else . end)
else empty
end)
else empty
end; |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #Jsish | Jsish | /* Classify Deficient, Perfect and Abdundant integers */
function classifyDPA(stop:number, start:number=0, step:number=1):array {
var dpa = [1, 0, 0];
for (var n=start; n<=stop; n+=step) {
for (var ds=0, d=1, e=n/2+1; d<e; d+=1) if (n%d == 0) ds += d;
dpa[ds < n ? 0 : ds==n ? 1 : 2] += 1;
}
return dpa;
}
var dpa = classifyDPA(20000, 2);
printf('Deficient: %d, Perfect: %d, Abundant: %d\n', dpa[0], dpa[1], dpa[2]); |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Kotlin | Kotlin | import java.nio.charset.StandardCharsets
import java.nio.file.Files
import java.nio.file.Paths
enum class AlignFunction {
LEFT { override fun invoke(s: String, l: Int) = ("%-" + l + 's').format(("%" + s.length + 's').format(s)) },
RIGHT { override fun invoke(s: String, l: Int) = ("%-" + l + 's').format(("%" + l + 's').format(s)) },
CENTER { override fun invoke(s: String, l: Int) = ("%-" + l + 's').format(("%" + ((l + s.length) / 2) + 's').format(s)) };
abstract operator fun invoke(s: String, l: Int): String
}
/** Aligns fields into columns, separated by "|".
* @constructor Initializes columns aligner from lines in a list of strings.
* @property lines Lines in a single string. Empty string does form a column.
*/
class ColumnAligner(val lines: List<String>) {
operator fun invoke(a: AlignFunction) : String {
var result = ""
for (lineWords in words) {
for (i in lineWords.indices) {
if (i == 0)
result += '|'
result += a(lineWords[i], column_widths[i])
result += '|'
}
result += '\n'
}
return result
}
private val words = arrayListOf<Array<String>>()
private val column_widths = arrayListOf<Int>()
init {
lines.forEach {
val lineWords = java.lang.String(it).split("\\$")
words += lineWords
for (i in lineWords.indices) {
if (i >= column_widths.size) {
column_widths += lineWords[i].length
} else {
column_widths[i] = Math.max(column_widths[i], lineWords[i].length)
}
}
}
}
}
fun main(args: Array<String>) {
if (args.isEmpty()) {
println("Usage: ColumnAligner file [L|R|C]")
return
}
val ca = ColumnAligner(Files.readAllLines(Paths.get(args[0]), StandardCharsets.UTF_8))
val alignment = if (args.size >= 2) args[1] else "L"
when (alignment) {
"L" -> print(ca(AlignFunction.LEFT))
"R" -> print(ca(AlignFunction.RIGHT))
"C" -> print(ca(AlignFunction.CENTER))
else -> System.err.println("Error! Unknown alignment: " + alignment)
}
} |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Transd | Transd |
#lang transd
MainModule: {
poly: (λ n Long()
(with v Vector<Long>([1])
(for i in Range(n) do
(append v (/ (* (get v -1) (- (- n i))) (to-Long (+ i 1))))
)
(reverse v)
(ret v)
)
),
aks_test: (λ n Long() -> Bool()
(if (< n 2) (ret false))
(with v (poly n)
(set-el v 0 (+ (get v 0) 1))
(ret (not (any Range(in: v 0 -1) (λ (mod @it n)))))
)
),
_start: (λ (with v Vector<Long>()
(for p in Seq( 12 ) do
(set v (poly p))
(textout "(x - 1)^" p " = ")
(for i in v do (textout :sign i "x^" @idx " "))
(textout "\n")
)
(textout "\nList of primes in 2-62 interval:\n")
(for p in Seq( 2 62 ) do
(if (aks_test p) (textout p " "))
)
))
} |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Oforth | Oforth | import: mapping
import: collect
import: quicksort
: anagrams
| m |
"unixdict.txt" File new groupBy( #sort )
dup sortBy( #[ second size] ) last second size ->m
filter( #[ second size m == ] )
apply ( #[ second .cr ] )
; |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Tcl | Tcl | package require Tcl 8.6
# make the creation of coroutines without procedures simpler
proc coro {name arguments body args} {
coroutine $name apply [list $arguments $body] {*}$args
}
# Wrap the feeding of values in and out of a generator
proc coloop {var body} {
set val [info coroutine]
upvar 1 $var v
while 1 {
set v [yield $val]
if {$v eq "stop"} break
set val [uplevel 1 $body]
}
}
# The outer coroutine is the accumulator factory
# The inner coroutine is the particular accumulator
coro accumulator {} {
coloop n {
coro accumulator.[incr counter] n {
coloop i {
set n [expr {$n + $i}]
}
} $n
}
} |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #TXR | TXR | (defun accumulate (sum)
(lambda (n)
(inc sum n)))
;; test
(for ((f (accumulate 0)) num)
((set num (iread : : nil)))
((format t "~s -> ~s\n" num [f num])))
(exit 0) |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #Component_Pascal | Component Pascal |
MODULE NpctAckerman;
IMPORT StdLog;
VAR
m,n: INTEGER;
PROCEDURE Ackerman (x,y: INTEGER):INTEGER;
BEGIN
IF x = 0 THEN RETURN y + 1
ELSIF y = 0 THEN RETURN Ackerman (x - 1 , 1)
ELSE
RETURN Ackerman (x - 1 , Ackerman (x , y - 1))
END
END Ackerman;
PROCEDURE Do*;
BEGIN
FOR m := 0 TO 3 DO
FOR n := 0 TO 6 DO
StdLog.Int (Ackerman (m, n));StdLog.Char (' ')
END;
StdLog.Ln
END;
StdLog.Ln
END Do;
END NpctAckerman.
|
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #Julia | Julia |
function pcontrib(p::Int64, a::Int64)
n = one(p)
pcon = one(p)
for i in 1:a
n *= p
pcon += n
end
return pcon
end
function divisorsum(n::Int64)
dsum = one(n)
for (p, a) in factor(n)
dsum *= pcontrib(p, a)
end
dsum -= n
end
|
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Lambdatalk | Lambdatalk |
{def txt
Given$a$text$file$of$many$lines,$where$fields$within$a$line\$are$delineated$by$a$single$'dollar'$character,$write$a$program\$that$aligns$each$column$of$fields$by$ensuring$that$words$in$each\$column$are$separated$by$at$least$one$space.\$Further,$allow$for$each$word$in$a$column$to$be$either$left\$justified,$right$justified,$or$center$justified$within$its$column.}
-> txt
{def columns // function's name
{def columns.r // loop function
{lambda {:just :a :b}
{if {A.empty? :a} // end of loop
then :b // return the string
else {columns.r :just // justification
{A.rest :a}. // loop on next char
{if {W.equal? {A.first :a} \} // if end of line
then < tr> :b // open a table row
else {if {W.equal? {A.first :a} $} // if space between words
then < td style="text-align::just;">:b // open a table data with justif
else {A.first :a}:b }} } }}} // else add character
{lambda {:just :txt} // main function
{table // open an HTML table
{columns.r // call the loop function
:just // justification
{A.reverse {A.split ${:txt}}} // split and reverse
. // end point
}}}}
-> columns
{columns left txt}
-> Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column..
{columns center txt} and {columns right txt} outputs can be seen in this website: http://lambdaway.free.fr/lambdawalks/?view=align_columns
|
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #uBasic.2F4tH | uBasic/4tH | For n = 0 To 9
Push n : Gosub _coef : Gosub _drop
Print "(x-1)^";n;" = ";
Push n : Gosub _show
Print
Next
Print
Print "primes (never mind the 1):";
For n = 1 To 34
Push n : Gosub _isprime
If Pop() Then Print " ";n;
Next
Print
End
' show polynomial expansions
_show ' ( n --)
Do
If @(Tos()) > -1 Then Print "+";
Print @(Tos());"x^";Tos();
While (Tos())
Push Pop() - 1
Loop
Gosub _drop
Return
' test whether number is a prime
_isprime ' ( n --)
Gosub _coef
i = Tos()
@(0) = @(0) + 1
@(i) = @(i) - 1
Do While (i) * ((@(i) % Tos()) = 0)
i = i - 1
Loop
Gosub _drop
Push (i = 0)
Return
' generate coefficients
_coef ' ( n -- n)
If (Tos() < 0) + (Tos() > 34) Then End
' gracefully deal with range issue
i = 0
@(i) = 1
Do While i < Tos()
j = i
@(j+1) = 1
Do While j > 0
@(j) = @(j-1) - @(j)
j = j - 1
Loop
@(0) = -@(0)
i = i + 1
Loop
Return
' drop a value from the stack
_drop ' ( n --)
If Pop() Endif
Return |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #VBA | VBA |
'-- Does not work for primes above 97, which is actually beyond the original task anyway.
'-- Translated from the C version, just about everything is (working) out-by-1, what fun.
'-- This updated VBA version utilizes the Decimal datatype to handle numbers requiring
'-- more than 32 bits.
Const MAX = 99
Dim c(MAX + 1) As Variant
Private Sub coef(n As Integer)
'-- out-by-1, ie coef(1)==^0, coef(2)==^1, coef(3)==^2 etc.
c(n) = CDec(1) 'converts c(n) from Variant to Decimal, a 12 byte data type
For i = n - 1 To 2 Step -1
c(i) = c(i) + c(i - 1)
Next i
End Sub
Private Function is_prime(fn As Variant) As Boolean
fn = CDec(fn)
Call coef(fn + 1) '-- (I said it was out-by-1)
For i = 2 To fn - 1 '-- (technically "to n" is more correct)
If c(i) - fn * Int(c(i) / fn) <> 0 Then 'c(i) Mod fn <> 0 Then --Mod works upto 32 bit numbers
is_prime = False: Exit Function
End If
Next i
is_prime = True
End Function
Private Sub show(n As Integer)
'-- (As per coef, this is (working) out-by-1)
Dim ci As Variant
For i = n To 1 Step -1
ci = c(i)
If ci = 1 Then
If (n - i) Mod 2 = 0 Then
If i = 1 Then
If n = 1 Then
ci = "1"
Else
ci = "+1"
End If
Else
ci = ""
End If
Else
ci = "-1"
End If
Else
If (n - i) Mod 2 = 0 Then
ci = "+" & ci
Else
ci = "-" & ci
End If
End If
If i = 1 Then '-- ie ^0
Debug.Print ci
Else
If i = 2 Then '-- ie ^1
Debug.Print ci & "x";
Else
Debug.Print ci & "x^" & i - 1;
End If
End If
Next i
End Sub
Public Sub AKS_test_for_primes()
Dim n As Integer
For n = 1 To 10 '-- (0 to 9 really)
coef n
Debug.Print "(x-1)^" & n - 1 & " = ";
show n
Next n
Debug.Print "primes (<="; MAX; "):"
coef 2 '-- (needed to reset c, if we want to avoid saying 1 is prime...)
For n = 2 To MAX
If is_prime(n) Then
Debug.Print n;
End If
Next n
End Sub
|
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #ooRexx | ooRexx |
-- This assumes you've already downloaded the following file and placed it
-- in the current directory: http://wiki.puzzlers.org/pub/wordlists/unixdict.txt
-- There are several different ways of reading the file. I chose the
-- supplier method just because I haven't used it yet in any other examples.
source = .stream~new('unixdict.txt')~supplier
-- this holds our mappings of the anagrams
anagrams = .directory~new
count = 0 -- this is used to keep track of the maximums
loop while source~available
word = source~item
-- this produces a string consisting of the characters in sorted order
-- Note: the ~~ used to invoke sort makes that message return value be
-- the target array. The sort method does not normally have a return value.
key = word~makearray('')~~sort~tostring("l", "")
-- make sure we have an accumulator collection for this key
list = anagrams[key]
if list == .nil then do
list = .array~new
anagrams[key] = list
end
-- this word is now associate with this key
list~append(word)
-- and see if this is a new highest count
count = max(count, list~items)
source~next
end
loop letters over anagrams
list = anagrams[letters]
if list~items >= count then
say letters":" list~makestring("l", ", ")
end
|
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #Unicon | Unicon | procedure main()
a := genAcc(3)
b := genAcc(5)
write(" " ,center("a",5), " ", center("b", 5))
write("genAcc: ", right(a(4),5), " ", right(b(4), 5))
write("genAcc: ", right(a(2),5), " ", right(b(3),5))
write("genAcc: ", right(a(4.5),5)," ", right(b(1.3),5))
end
procedure genAcc(n) # The generator factory
return makeProc { while i := (n@&source)[1] do n +:= i }
end
procedure makeProc(A) # A Programmer-Defined Control Operation
return (@A[1],A[1])
end |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #Coq | Coq | Require Import Arith.
Fixpoint A m := fix A_m n :=
match m with
| 0 => n + 1
| S pm =>
match n with
| 0 => A pm 1
| S pn => A pm (A_m pn)
end
end. |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n) == n then n is classed as perfect (OEIS A000396).
if P(n) > n then n is classed as abundant (OEIS A005101).
Example
6 has proper divisors of 1, 2, and 3.
1 + 2 + 3 = 6, so 6 is classed as a perfect number.
Task
Calculate how many of the integers 1 to 20,000 (inclusive) are in each of the three classes.
Show the results here.
Related tasks
Aliquot sequence classifications. (The whole series from which this task is a subset.)
Proper divisors
Amicable pairs
| #K | K |
/Classification of numbers into abundant, perfect and deficient
/ numclass.k
/return 0,1 or -1 if perfect or abundant or deficient respectively
numclass: {s:(+/&~x!'!1+x)-x; :[s>x;:1;:[s<x;:-1;:0]]}
/classify numbers from 1 to 20000 into respective groups
c: =numclass' 1+!20000
/print statistics
`0: ,"Deficient = ", $(#c[0])
`0: ,"Perfect = ", $(#c[1])
`0: ,"Abundant = ", $(#c[2])
|
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, or center justified within its column.
Use the following text to test your programs:
Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
Note that:
The example input texts lines may, or may not, have trailing dollar characters.
All columns should share the same alignment.
Consecutive space characters produced adjacent to the end of lines are insignificant for the purposes of the task.
Output text will be viewed in a mono-spaced font on a plain text editor or basic terminal.
The minimum space between columns should be computed from the text and not hard-coded.
It is not a requirement to add separating characters between or around columns.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Lasso | Lasso | #!/usr/bin/lasso9
local(text = "Given$a$text$file$of$many$lines,$where$fields$within$a$line$
are$delineated$by$a$single$'dollar'$character,$write$a$program
that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$
column$are$separated$by$at$least$one$space.
Further,$allow$for$each$word$in$a$column$to$be$either$left$
justified,$right$justified,$or$center$justified$within$its$column.
")
define go_left(text::array, width::integer) => {
local(output = string)
with row in #text do {
with word in #row do {
#output -> append(string(#word) -> padtrailing(#width + 1)&)
}
#output -> append('\n')
}
return #output
}
define go_right(text::array, width::integer) => {
local(output = string)
with row in #text do {
with word in #row do {
#output -> append(string(#word) -> padleading(#width + 1)&)
}
#output -> append('\n')
}
return #output
}
define go_center(text::array, width::integer) => {
local(output = string)
with row in #text do {
with word in #row do {
local(
padlength = (#width + 1 - #word -> size),
padleft = (' ' * (#padlength / 2)),
padright = (' ' * (#padlength - #padleft -> size))
)
#output -> append(#padleft + string(#word) + #padright)
}
#output -> append('\n')
}
return #output
}
define prepcols(text::string) => {
local(
result = array,
maxwidth = 0
)
with row in #text -> split('\n') do {
#row -> removetrailing('$')
#result -> insert(#row -> split('$'))
}
with word in delve(#result) do {
#word -> size > #maxwidth ? #maxwidth = #word -> size
}
stdoutnl('Left aligned result: \n' + go_left(#result, #maxwidth))
stdoutnl('Right aligned result: \n' + go_right(#result, #maxwidth))
stdoutnl('Centered result: \n' + go_center(#result, #maxwidth))
}
prepcols(#text) |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Vlang | Vlang | fn bc(p int) []i64 {
mut c := []i64{len: p+1}
mut r := i64(1)
for i, half := 0, p/2; i <= half; i++ {
c[i] = r
c[p-i] = r
r = r * i64(p-i) / i64(i+1)
}
for i := p - 1; i >= 0; i -= 2 {
c[i] = -c[i]
}
return c
}
fn main() {
for p := 0; p <= 7; p++ {
println("$p: ${pp(bc(p))}")
}
for p := 2; p < 50; p++ {
if aks(p) {
print("$p ")
}
}
println('')
}
const e = [`²`,`³`,`⁴`,`⁵`,`⁶`,`⁷`]
fn pp(c []i64) string {
mut s := ''
if c.len == 1 {
return c[0].str()
}
p := c.len - 1
if c[p] != 1 {
s = c[p].str()
}
for i := p; i > 0; i-- {
s += "x"
if i != 1 {
s += e[i-2].str()
}
d := c[i-1]
if d < 0 {
s += " - ${-d}"
} else {
s += " + $d"
}
}
return s
}
fn aks(p int) bool {
mut c := bc(p)
c[p]--
c[0]++
for d in c {
if d%i64(p) != 0 {
return false
}
}
return true
} |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial expansion of
(
x
−
1
)
p
−
(
x
p
−
1
)
{\displaystyle (x-1)^{p}-(x^{p}-1)}
are divisible by
p
{\displaystyle p}
.
Example
Using
p
=
3
{\displaystyle p=3}
:
(x-1)^3 - (x^3 - 1)
= (x^3 - 3x^2 + 3x - 1) - (x^3 - 1)
= -3x^2 + 3x
And all the coefficients are divisible by 3, so 3 is prime.
Note:
This task is not the AKS primality test. It is an inefficient exponential time algorithm discovered in the late 1600s and used as an introductory lemma in the AKS derivation.
Task
Create a function/subroutine/method that given
p
{\displaystyle p}
generates the coefficients of the expanded polynomial representation of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
.
Use the function to show here the polynomial expansions of
(
x
−
1
)
p
{\displaystyle (x-1)^{p}}
for
p
{\displaystyle p}
in the range 0 to at least 7, inclusive.
Use the previous function in creating another function that when given
p
{\displaystyle p}
returns whether
p
{\displaystyle p}
is prime using the theorem.
Use your test to generate a list of all primes under 35.
As a stretch goal, generate all primes under 50 (needs integers larger than 31-bit).
References
Agrawal-Kayal-Saxena (AKS) primality test (Wikipedia)
Fool-Proof Test for Primes - Numberphile (Video). The accuracy of this video is disputed -- at best it is an oversimplification.
| #Wren | Wren | var bc = Fn.new { |p|
var c = List.filled(p+1, 0)
var r = 1
var half = (p/2).floor
for (i in 0..half) {
c[i] = r
c[p-i] = r
r = (r * (p-i) / (i+1)).floor
}
var j = p - 1
while (j >= 0) {
c[j] = -c[j]
j = j - 2
}
return c
}
var e = "²³⁴⁵⁶⁷".codePoints.toList
var pp = Fn.new { |c|
if (c.count == 1) return "%(c[0])"
var p = c.count - 1
var s = ""
if (c[p] != 1) s = "%(c[p])"
if (p == 0) return s
for (i in p..1) {
s = s + "x"
if (i != 1) s = s + String.fromCodePoint(e[i-2])
var d = c[i-1]
s = s + ((d < 0) ? " - %(-d)" : " + %(d)")
}
return s
}
var aks = Fn.new { |p|
var c = bc.call(p)
c[p] = c[p] - 1
c[0] = c[0] + 1
for (d in c) {
if (d%p != 0) return false
}
return true
}
for (p in 0..7) System.print("%(p): %(pp.call(bc.call(p)))")
System.print("\nAll primes under 50:")
for (p in 2..49) if (aks.call(p)) System.write("%(p) ")
System.print() |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
Ordered words
Palindrome detection
Semordnilap
Anagrams
Anagrams/Deranged anagrams
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurrences of a substring
Count how many vowels and consonants occur in a string
Remove/replace
XXXX redacted
Conjugate a Latin verb
Remove vowels from a string
String interpolation (included)
Strip block comments
Strip comments from a string
Strip a set of characters from a string
Strip whitespace from a string -- top and tail
Strip control codes and extended characters from a string
Anagrams/Derangements/shuffling
Word wheel
ABC problem
Sattolo cycle
Knuth shuffle
Ordered words
Superpermutation minimisation
Textonyms (using a phone text pad)
Anagrams
Anagrams/Deranged anagrams
Permutations/Derangements
Find/Search/Determine
ABC words
Odd words
Word ladder
Semordnilap
Word search
Wordiff (game)
String matching
Tea cup rim text
Alternade words
Changeable words
State name puzzle
String comparison
Unique characters
Unique characters in each string
Extract file extension
Levenshtein distance
Palindrome detection
Common list elements
Longest common suffix
Longest common prefix
Compare a list of strings
Longest common substring
Find common directory path
Words from neighbour ones
Change e letters to i in words
Non-continuous subsequences
Longest common subsequence
Longest palindromic substrings
Longest increasing subsequence
Words containing "the" substring
Sum of the digits of n is substring of n
Determine if a string is numeric
Determine if a string is collapsible
Determine if a string is squeezable
Determine if a string has all unique characters
Determine if a string has all the same characters
Longest substrings without repeating characters
Find words which contains all the vowels
Find words which contains most consonants
Find words which contains more than 3 vowels
Find words which first and last three letters are equals
Find words which odd letters are consonants and even letters are vowels or vice_versa
Formatting
Substring
Rep-string
Word wrap
String case
Align columns
Literals/String
Repeat a string
Brace expansion
Brace expansion using ranges
Reverse a string
Phrase reversals
Comma quibbling
Special characters
String concatenation
Substring/Top and tail
Commatizing numbers
Reverse words in a string
Suffixation of decimal numbers
Long literals, with continuations
Numerical and alphabetical suffixes
Abbreviations, easy
Abbreviations, simple
Abbreviations, automatic
Song lyrics/poems/Mad Libs/phrases
Mad Libs
Magic 8-ball
99 Bottles of Beer
The Name Game (a song)
The Old lady swallowed a fly
The Twelve Days of Christmas
Tokenize
Text between
Tokenize a string
Word break problem
Tokenize a string with escaping
Split a character string based on change of character
Sequences
Show ASCII table
De Bruijn sequences
Self-referential sequences
Generate lower case ASCII alphabet
| #Oz | Oz | declare
%% Helper function
fun {ReadLines Filename}
File = {New class $ from Open.file Open.text end init(name:Filename)}
in
for collect:C break:B do
case {File getS($)} of false then {File close} {B}
[] Line then {C Line}
end
end
end
%% Groups anagrams by using a mutable dictionary
%% with sorted words as keys
WordDict = {Dictionary.new}
for Word in {ReadLines "unixdict.txt"} do
Keyword = {String.toAtom {Sort Word Value.'<'}}
in
WordDict.Keyword := Word|{CondSelect WordDict Keyword nil}
end
Sets = {Dictionary.items WordDict}
%% Filter such that only the largest sets remain
MaxSetSize = {FoldL {Map Sets Length} Max 0}
LargestSets = {Filter Sets fun {$ S} {Length S} == MaxSetSize end}
in
%% Display result (make sure strings are shown as string, not as number lists)
{Inspector.object configureEntry(widgetShowStrings true)}
{Inspect LargestSets} |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #UNIX_Shell | UNIX Shell | #!/bin/sh
accumulator() {
# Define a global function named $1
# with a global variable named ${1}_sum.
eval "${1}_sum=\$2"
eval "$1() {
${1}_sum=\$(echo \"(\$${1}_sum) + (\$2)\" | bc)
eval \"\$1=\\\$${1}_sum\" # Provide the current sum.
}"
}
accumulator x 1
x r 5
accumulator y 3
x r 2.3
echo $r
y r -3000
echo $r |
http://rosettacode.org/wiki/Accumulator_factory | Accumulator factory | A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulator (including the initial value passed when the accumulator was created).
Rules
The detailed rules are at http://paulgraham.com/accgensub.html and are reproduced here for simplicity (with additions in small italic text).
Before you submit an example, make sure the function
Takes a number n and returns a function (lets call it g), that takes a number i, and returns n incremented by the accumulation of i from every call of function g(i).
Although these exact function and parameter names need not be used
Works for any numeric type-- i.e. can take both ints and floats and returns functions that can take both ints and floats. (It is not enough simply to convert all input to floats. An accumulator that has only seen integers must return integers.) (i.e., if the language doesn't allow for numeric polymorphism, you have to use overloading or something like that)
Generates functions that return the sum of every number ever passed to them, not just the most recent. (This requires a piece of state to hold the accumulated value, which in turn means that pure functional languages can't be used for this task.)
Returns a real function, meaning something that you can use wherever you could use a function you had defined in the ordinary way in the text of your program. (Follow your language's conventions here.)
Doesn't store the accumulated value or the returned functions in a way that could cause them to be inadvertently modified by other code. (No global variables or other such things.)
E.g. if after the example, you added the following code (in a made-up language) where the factory function is called foo:
x = foo(1);
x(5);
foo(3);
print x(2.3);
It should print 8.3. (There is no need to print the form of the accumulator function returned by foo(3); it's not part of the task at all.)
Task
Create a function that implements the described rules.
It need not handle any special error cases not described above. The simplest way to implement the task as described is typically to use a closure, providing the language supports them.
Where it is not possible to hold exactly to the constraints above, describe the deviations.
| #VBScript | VBScript | class accumulator
dim A
public default function acc(x)
A = A + x
acc = A
end function
public property get accum
accum = A
end property
end class |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
−
1
,
1
)
if
m
>
0
and
n
=
0
A
(
m
−
1
,
A
(
m
,
n
−
1
)
)
if
m
>
0
and
n
>
0.
{\displaystyle A(m,n)={\begin{cases}n+1&{\mbox{if }}m=0\\A(m-1,1)&{\mbox{if }}m>0{\mbox{ and }}n=0\\A(m-1,A(m,n-1))&{\mbox{if }}m>0{\mbox{ and }}n>0.\end{cases}}}
Its arguments are never negative and it always terminates.
Task
Write a function which returns the value of
A
(
m
,
n
)
{\displaystyle A(m,n)}
. Arbitrary precision is preferred (since the function grows so quickly), but not required.
See also
Conway chained arrow notation for the Ackermann function.
| #Crystal | Crystal | def ack(m, n)
if m == 0
n + 1
elsif n == 0
ack(m-1, 1)
else
ack(m-1, ack(m, n-1))
end
end
#Example:
(0..3).each do |m|
puts (0..6).map { |n| ack(m, n) }.join(' ')
end
|
Subsets and Splits