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http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#Fortran
Fortran
program main implicit none integer :: a integer :: f, g logical :: lresult interface integer function h(a,b,c) integer :: a, b integer, optional :: c end function end interface write(*,*) 'no arguments: ', f() write(*,*) '-----------------' write(*,*) 'fixed arguments: ', g(5,8,lresult) write(*,*) '-----------------' write(*,*) 'optional arguments: ', h(5,8), h(5,8,4) write(*,*) '-----------------' write(*,*) 'function with variable arguments: Does not apply!' write(*,*) 'An option is to pass arrays of variable lengths.' write(*,*) '-----------------' write(*,*) 'named arguments: ', h(c=4,b=8,a=5) write(*,*) '-----------------' write(*,*) 'function in statement context: Does not apply!' write(*,*) '-----------------' write(*,*) 'Fortran passes memory location of variables as arguments.' write(*,*) 'So an argument can hold the return value.' write(*,*) 'function result: ', g(5,8,lresult) , ' function successful? ', lresult write(*,*) '-----------------' write(*,*) 'Distinguish between built-in and user-defined functions: Does not apply!' write(*,*) '-----------------' write(*,*) 'Calling a subroutine: ' a = 30 call sub(a) write(*,*) 'Function call: ', f() write(*,*) '-----------------' write(*,*) 'All variables are passed as pointers.' write(*,*) 'Problems can arise if instead of sub(a), one uses sub(10).' write(*,*) '-----------------' end program   !no argument integer function f() f = 10 end function   !fixed number of arguments integer function g(a, b, lresult) integer :: a, b logical :: lresult g = a+b lresult = .TRUE. end function   !optional arguments integer function h(a, b, c) integer :: a, b integer, optional :: c   h = a+b if(present(c)) then h = h+10*c end if end function   !subroutine subroutine sub(a) integer :: a a = a*100 write(*,*) 'Output of subroutine: ', a end subroutine  
http://rosettacode.org/wiki/Catamorphism
Catamorphism
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value. Task Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language. See also Wikipedia article:   Fold Wikipedia article:   Catamorphism
#VBA
VBA
Public Sub reduce() s = [{1,2,3,4,5}] Debug.Print WorksheetFunction.Sum(s) Debug.Print WorksheetFunction.Product(s) End Sub
http://rosettacode.org/wiki/Catamorphism
Catamorphism
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value. Task Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language. See also Wikipedia article:   Fold Wikipedia article:   Catamorphism
#Vlang
Vlang
vfn main() { n := [1, 2, 3, 4, 5]   println(reduce(add, n)) println(reduce(sub, n)) println(reduce(mul, n)) }   fn add(a int, b int) int { return a + b } fn sub(a int, b int) int { return a - b } fn mul(a int, b int) int { return a * b }   fn reduce(rf fn(int, int) int, m []int) int { mut r := m[0] for v in m[1..] { r = rf(r, v) } return r }
http://rosettacode.org/wiki/Cartesian_product_of_two_or_more_lists
Cartesian product of two or more lists
Task Show one or more idiomatic ways of generating the Cartesian product of two arbitrary lists in your language. Demonstrate that your function/method correctly returns: {1, 2} × {3, 4} = {(1, 3), (1, 4), (2, 3), (2, 4)} and, in contrast: {3, 4} × {1, 2} = {(3, 1), (3, 2), (4, 1), (4, 2)} Also demonstrate, using your function/method, that the product of an empty list with any other list is empty. {1, 2} × {} = {} {} × {1, 2} = {} For extra credit, show or write a function returning the n-ary product of an arbitrary number of lists, each of arbitrary length. Your function might, for example, accept a single argument which is itself a list of lists, and return the n-ary product of those lists. Use your n-ary Cartesian product function to show the following products: {1776, 1789} × {7, 12} × {4, 14, 23} × {0, 1} {1, 2, 3} × {30} × {500, 100} {1, 2, 3} × {} × {500, 100}
#zkl
zkl
zkl: Walker.cproduct(List(1,2),List(3,4)).walk().println(); L(L(1,3),L(1,4),L(2,3),L(2,4)) zkl: foreach a,b in (List(1,2),List(3,4)){ print("(%d,%d) ".fmt(a,b)) } (1,3) (1,4) (2,3) (2,4)   zkl: Walker.cproduct(List(3,4),List(1,2)).walk().println(); L(L(3,1),L(3,2),L(4,1),L(4,2))
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#langur
langur
val .factorial = f if(.x < 2: 1; .x x self(.x - 1)) val .catalan = f(.n) .factorial(2 x .n) / .factorial(.n+1) / .factorial(.n)   for .i in 0..15 { writeln $"\.i:2;: \(.catalan(.i):10)" }   writeln "10000: ", .catalan(10000)
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#PHP
PHP
function getitem($s,$depth=0) { $out = ['']; while ($s) { $c = $s[0]; if ($depth && ($c == ',' || $c == '}')) { return [$out, $s]; } if ($c == '{') { $x = getgroup(substr($s, 1), $depth + 1); if($x) { $tmp = []; foreach($out as $a) { foreach($x[0] as $b) { $tmp[] = $a . $b; } } $out = $tmp; $s = $x[1]; continue; } } if ($c == '\\' && strlen($s) > 1) { list($s, $c) = [substr($s, 1), ($c . $s[1])]; }   $tmp = []; foreach($out as $a) { $tmp[] = $a . $c; } $out = $tmp; $s = substr($s, 1);   } return [$out, $s]; } function getgroup($s,$depth) { list($out, $comma) = [[], false]; while ($s) { list($g, $s) = getitem($s, $depth); if (!$s) { break; } $out = array_merge($out, $g); if ($s[0] == '}') { if ($comma) { return [$out, substr($s, 1)]; }   $tmp = []; foreach($out as $a) { $tmp[] = '{' . $a . '}'; } return [$tmp, substr($s, 1)]; } if ($s[0] == ',') { list($comma, $s) = [true, substr($s, 1)]; } } return null; }   $lines = <<< 'END' ~/{Downloads,Pictures}/*.{jpg,gif,png} It{{em,alic}iz,erat}e{d,}, please. {,{,gotta have{ ,\, again\, }}more }cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} END;   foreach( explode("\n", $lines) as $line ) { printf("\n%s\n", $line); foreach( getitem($line)[0] as $expansion ) { printf(" %s\n", $expansion); } }
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#Haskell
Haskell
import Data.Numbers.Primes (primes)   isBrazil :: Int -> Bool isBrazil n = 7 <= n && (even n || any (monoDigit n) [2 .. n - 2])   monoDigit :: Int -> Int -> Bool monoDigit n b = let (q, d) = quotRem n b in d == snd (until (uncurry (flip ((||) . (d /=)) . (0 ==))) ((`quotRem` b) . fst) (q, d))   main :: IO () main = mapM_ (\(s, xs) -> (putStrLn . concat) [ "First 20 " , s , " Brazilians:\n" , show . take 20 $ filter isBrazil xs , "\n" ]) [([], [1 ..]), ("odd", [1,3 ..]), ("prime", primes)]
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#FutureBasic
FutureBasic
window 1, @"Calendar", (0, 0, 520, 520 )   Str255 a   open "UNIX", 1,"cal 1969" do line input #1, a print a until eof(1) close 1   HandleEvents
http://rosettacode.org/wiki/Brownian_tree
Brownian tree
Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a   Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere within the field. Where is not particularly important; it could be randomized, or it could be a fixed point. Particles are injected into the field, and are individually given a (typically random) motion pattern. When a particle collides with the seed or tree, its position is fixed, and it's considered to be part of the tree. Because of the lax rules governing the random nature of the particle's placement and motion, no two resulting trees are really expected to be the same, or even necessarily have the same general shape.
#JavaScript
JavaScript
function brownian(canvasId, messageId) { var canvas = document.getElementById(canvasId); var ctx = canvas.getContext("2d");   // Options var drawPos = true; var seedResolution = 50; var clearShade = 0; // 0..255   // Static state var width = canvas.width; var height = canvas.height; var cx = width/2; var cy = height/2; var clearStyle = "rgba("+clearShade+", "+clearShade+", "+clearShade+", 1)";   // Utilities function radius(x,y) { return Math.sqrt((x-cx)*(x-cy)+(y-cx)*(y-cy)); } function test(x, y) { if (x < 0 || y < 0 || x >= width || y >= height) return false; var data = ctx.getImageData(x, y, 1, 1).data; return data[0] != clearShade || data[1] != clearShade || data[2] != clearShade; } var shade = 120; function setc(x, y, c) { //var imgd = ctx.createImageData(1, 1); //var pix = imgd.data; //pix[0] = pix[1] = pix[2] = c == 255 ? 255 : shade; //pix[3] = 255; //shade = (shade + 1) % 254; //ctx.putImageData(imgd, x, y); //ctx.fillStyle = "rgba("+c+", "+c+", "+c+", 1)"; shade = (shade + 0.02) % 360; if (c) { ctx.fillStyle = "hsl("+shade+", 100%, 50%)"; } else { ctx.fillStyle = clearStyle; } ctx.fillRect (x, y, 1, 1); } function set(x,y) { setc(x,y,true); } function clear(x,y) { setc(x,y,false); }   // Initialize canvas to blank opaque ctx.fillStyle = clearStyle; ctx.fillRect (0, 0, width, height);   // Current position var x; var y;   // Farthest distance from center a particle has yet been placed. var closeRadius = 1;   // Place seed set(cx, cy);   // Choose a new random position for a particle (not necessarily unoccupied) function newpos() { // Wherever particles are injected, the tree will tend to grow faster // toward it. Ideally, particles wander in from infinity; the best we // could do is to have them wander in from the edge of the field. // But in order to have the rendering occur in a reasonable time when // the seed is small, without too much visible bias, we instead place // the particles in a coarse grid. The final tree will cover every // point on the grid. // // There's probably a better strategy than this. x = Math.floor(Math.random()*(width/seedResolution))*seedResolution; y = Math.floor(Math.random()*(height/seedResolution))*seedResolution; } newpos();   var animation; animation = window.setInterval(function () { if (drawPos) clear(x,y); for (var i = 0; i < 10000; i++) { var ox = x; var oy = y;   // Changing this to use only the first four directions will result // in a denser tree. switch (Math.floor(Math.random()*8)) { case 0: x++; break; case 1: x--; break; case 2: y++; break; case 3: y--; break; case 4: x++; y++; break; case 5: x--; y++; break; case 6: x++; y--; break; case 7: x--; y--; break; } if (x < 0 || y < 0 || x >= width || y >= height || radius(x,y) > closeRadius+seedResolution+2) { // wandered out of bounds or out of interesting range of the // tree, so pick a new spot var progress = 1000; do { newpos(); progress--; } while ((test(x-1,y-1) || test(x,y-1) || test(x+1,y-1) || test(x-1,y ) || test(x,y ) || test(x+1,y ) || test(x-1,y+1) || test(x,y+1) || test(x+1,y+1)) && progress > 0); if (progress <= 0) { document.getElementById(messageId).appendChild( document.createTextNode("Stopped for lack of room.")); clearInterval(animation); break; } } if (test(x, y)) { // hit something, mark where we came from and pick a new spot set(ox,oy); closeRadius = Math.max(closeRadius, radius(ox,oy)); newpos(); } } if (drawPos) set(x,y); }, 1);   }
http://rosettacode.org/wiki/Bulls_and_cows
Bulls and cows
Bulls and Cows Task Create a four digit random number from the digits   1   to   9,   without duplication. The program should:   ask for guesses to this number   reject guesses that are malformed   print the score for the guess The score is computed as: The player wins if the guess is the same as the randomly chosen number, and the program ends. A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number. A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position. Related tasks   Bulls and cows/Player   Guess the number   Guess the number/With Feedback   Mastermind
#E
E
def Digit := 1..9 def Number := Tuple[Digit,Digit,Digit,Digit]   /** Choose a random number to be guessed. */ def pick4(entropy) { def digits := [1,2,3,4,5,6,7,8,9].diverge()   # Partial Fisher-Yates shuffle for i in 0..!4 { def other := entropy.nextInt(digits.size() - i) + i def t := digits[other] digits[other] := digits[i] digits[i] := t } return digits(0, 4) }   /** Compute the score of a guess. */ def scoreGuess(actual :Number, guess :Number) { var bulls := 0 var cows := 0 for i => digit in guess { if (digit == actual[i]) { bulls += 1 } else if (actual.indexOf1(digit) != -1) { cows += 1 } } return [bulls, cows] }   /** Parse a guess string into a list of digits (Number). */ def parseGuess(guessString, fail) :Number { if (guessString.size() != 4) { return fail(`I need four digits, not ${guessString.size()} digits.`) } else { var digits := [] for c in guessString { if (('1'..'9')(c)) { digits with= c - '0' } else { return fail(`I need a digit from 1 to 9, not "$c".`) } } return digits } }   /** The game loop: asking for guesses and reporting scores and win conditions. The return value is null or a broken reference if there was a problem. */ def bullsAndCows(askUserForGuess, tellUser, entropy) { def actual := pick4(entropy)   def gameTurn() { return when (def guessString := askUserForGuess <- ()) -> { escape tellAndContinue {   def guess := parseGuess(guessString, tellAndContinue) def [bulls, cows] := scoreGuess(actual, guess)   if (bulls == 4) { tellUser <- (`You got it! The number is $actual!`) null } else { tellAndContinue(`Your score for $guessString is $bulls bulls and $cows cows.`) }   } catch message { # The parser or scorer has something to say, and the game continues afterward when (tellUser <- (message)) -> { gameTurn() } } } catch p { # Unexpected problem of some sort tellUser <- ("Sorry, game crashed.") throw(p) } }   return gameTurn() }
http://rosettacode.org/wiki/Caesar_cipher
Caesar cipher
Task Implement a Caesar cipher, both encoding and decoding. The key is an integer from 1 to 25. This cipher rotates (either towards left or right) the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "mono-alphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys. Caesar cipher is identical to Vigenère cipher with a key of length 1. Also, Rot-13 is identical to Caesar cipher with key 13. Related tasks Rot-13 Substitution Cipher Vigenère Cipher/Cryptanalysis
#COBOL
COBOL
  identification division. program-id. caesar. data division. 1 msg pic x(50) value "The quick brown fox jumped over the lazy dog.". 1 offset binary pic 9(4) value 7. 1 from-chars pic x(52). 1 to-chars pic x(52). 1 tabl. 2 pic x(26) value "abcdefghijklmnopqrstuvwxyz". 2 pic x(26) value "ABCDEFGHIJKLMNOPQRSTUVWXYZ". 2 pic x(26) value "abcdefghijklmnopqrstuvwxyz". 2 pic x(26) value "ABCDEFGHIJKLMNOPQRSTUVWXYZ". procedure division. begin. display msg perform encrypt display msg perform decrypt display msg stop run .   encrypt. move tabl (1:52) to from-chars move tabl (1 + offset:52) to to-chars inspect msg converting from-chars to to-chars .   decrypt. move tabl (1 + offset:52) to from-chars move tabl (1:52) to to-chars inspect msg converting from-chars to to-chars . end program caesar.  
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Myrddin
Myrddin
use std   const main = { var f: uint64 = 1 var e: flt64 = 2.0 var e0: flt64 = 0.0 var n = 2   while e > e0 e0 = e f *= n e += 1.0 / (f : flt64) n++  ;; std.put("e: {}\n", e) }
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Nanoquery
Nanoquery
e0 = 0 e = 2 n = 0 fact = 1 while (e - e0) > 10^-15 e0 = e n += 1 fact *= 2*n*((2*n)+1) e += ((2.0*n)+2)/fact end   println "Computed e = " + e println "Number of iterations = " + n
http://rosettacode.org/wiki/Bulls_and_cows/Player
Bulls and cows/Player
Task Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts. One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list. Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring. Related tasks   Bulls and cows   Guess the number   Guess the number/With Feedback (Player)
#Raku
Raku
# we use the [] reduction meta operator along with the Cartesian Product # operator X to create the Cartesian Product of four times [1..9] and then get # all the elements where the number of unique digits is four. my @candidates = ([X] [1..9] xx 4).grep: *.unique == 4;   repeat { my $guess = @candidates.pick; my ($bulls, $cows) = read-score; @candidates .= grep: &score-correct;   # note how we declare our two subroutines within the repeat block. This # limits the scope in which the routines are known to the scope in which # they are needed and saves us a lot of arguments to our two routines. sub score-correct($a) { my $exact = [+] $a >>==<< $guess;   # number of elements of $a that match any element of $b my $loose = +$a.grep: any @$guess;   return $bulls == $exact && $cows == $loose - $exact; }   sub read-score() { loop { my $score = prompt "My guess: {$guess.join}.\n";   if $score ~~ m:s/^ $<bulls>=(\d) $<cows>=(\d) $/ and $<bulls> + $<cows> <= 4 { return +$<bulls>, +$<cows>; }   say "Please specify the number of bulls and cows"; } } } while @candidates > 1;   say @candidates ?? "Your secret number is {@candidates[0].join}!" !! "I think you made a mistake with your scoring.";
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers
Calendar - for "REAL" programmers
Task Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented   entirely without lowercase. Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide. (Hint: manually convert the code from the Calendar task to all UPPERCASE) This task also is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." Moreover this task is further inspired by the long lost corollary article titled: "Real programmers think in UPPERCASE"! Note: Whereas today we only need to worry about ASCII, UTF-8, UTF-16, UTF-32, UTF-7 and UTF-EBCDIC encodings, in the 1960s having code in UPPERCASE was often mandatory as characters were often stuffed into 36-bit words as 6 lots of 6-bit characters. More extreme words sizes include 60-bit words of the CDC 6000 series computers. The Soviets even had a national character set that was inclusive of all 4-bit, 5-bit, 6-bit & 7-bit depending on how the file was opened... And one rogue Soviet university went further and built a 1.5-bit based computer. Of course... as us Boomers have turned into Geezers we have become HARD OF HEARING, and suffer from chronic Presbyopia, hence programming in UPPERCASE is less to do with computer architecture and more to do with practically. :-) For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. FYI: a nice ASCII art file of Snoopy can be found at textfiles.com. Save with a .txt extension. Trivia: The terms uppercase and lowercase date back to the early days of the mechanical printing press. Individual metal alloy casts of each needed letter, or punctuation symbol, were meticulously added to a press block, by hand, before rolling out copies of a page. These metal casts were stored and organized in wooden cases. The more often needed minuscule letters were placed closer to hand, in the lower cases of the work bench. The less often needed, capitalized, majuscule letters, ended up in the harder to reach upper cases.
#Sidef
Sidef
-> DT { ('DATE'.("\LWC") + 'TIME'.("\LWC")).("\LREQUIRE") }   -> MONTHS_PER_COL { 6 } -> WEEK_DAY_NAMES { <MO TU WE TH FR SA SU> } -> MONTH_NAMES { <JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC> }   -> FMT_MONTH (YEAR, MONTH, STR="", WEEK_DAY=0) { STR = "%11\LS\E%9\LS\E\12".("\LSPRINTF")(MONTH_NAMES()[MONTH-1],'') STR += (WEEK_DAY_NAMES().("\LJOIN")(' ') + "\12")   -> DATE { DT().("\LNEW")("\LYEAR" => YEAR, "\LMONTH" => MONTH) }   WEEK_DAY = DATE().("\LDAY_OF_WEEK") STR += ([" "] * WEEK_DAY-1 -> ("\LJOIN")(" "))   -> LAST_DAY { DT().("\LLAST_DAY_OF_MONTH")( "\LYEAR" => YEAR, "\LMONTH" => MONTH ).("\LDAY") }   (DATE().("\LDAY") .. LAST_DAY()).("\LEACH")({ |DAY| (WEEK_DAY ~~ (2..7)) && (STR += " ")   (WEEK_DAY == 8) && ( STR += "\12" WEEK_DAY = 1 ) STR += ("%2\LD" % DAY) ++WEEK_DAY }) (WEEK_DAY < 8) && (STR += " ") STR += ([" "] * 8-WEEK_DAY -> ("\LJOIN")(" ")) STR += "\12" }   -> FMT_YEAR (YEAR, STR="", MONTH_STRS=[]) { MONTH_STRS = 12.("\LOF")({|I| FMT_MONTH(YEAR, I+1).("\LLINES") })   STR += (' '*(MONTHS_PER_COL()*10 + 2) + YEAR + "\12") (0..11 -> ("\LBY")(MONTHS_PER_COL())).("\LEACH")({ |MONTH| MONTH_STRS[MONTH] && ->() { { |I| MONTH_STRS[MONTH + I] && ( STR += MONTH_STRS[MONTH + I].("\LSHIFT") STR += ' '*2 ) } * MONTHS_PER_COL()   STR += "\12" MONTH_STRS[MONTH] && __FUNC__() }() STR += "\12" })   STR }   FMT_YEAR(ARGV ? ARGV[0].("\LTO_I") : 1969).("\LPRINT")
http://rosettacode.org/wiki/Call_a_foreign-language_function
Call a foreign-language function
Task Show how a foreign language function can be called from the language. As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can be copied if necessary. Get the result from strdup and print it using language means. Do not forget to free the result of strdup (allocated in the heap). Notes It is not mandated if the C run-time library is to be loaded statically or dynamically. You are free to use either way. C++ and C solutions can take some other language to communicate with. It is not mandatory to use strdup, especially if the foreign function interface being demonstrated makes that uninformative. See also   Use another language to call a function
#X86-64_Assembly
X86-64 Assembly
  option casemap:none   strdup proto :qword printf proto :qword, :vararg exit proto :dword   .data bstr db "String 1",0   .data? buff dq ?   .code main proc invoke printf, CSTR("Copying %s to buff with strdup using invoke....",10), addr bstr invoke strdup, addr bstr mov buff, rax invoke printf, CSTR("buff now = %s",10), buff invoke exit, 0 ret main endp end ;Now, we could target a specific ABI by assigning the call values to the registers like ;.code ;main proc ; lea rdi, bstr ; call strdup ; mov buff, rax ;main endp ;end  
http://rosettacode.org/wiki/Call_a_foreign-language_function
Call a foreign-language function
Task Show how a foreign language function can be called from the language. As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can be copied if necessary. Get the result from strdup and print it using language means. Do not forget to free the result of strdup (allocated in the heap). Notes It is not mandated if the C run-time library is to be loaded statically or dynamically. You are free to use either way. C++ and C solutions can take some other language to communicate with. It is not mandatory to use strdup, especially if the foreign function interface being demonstrated makes that uninformative. See also   Use another language to call a function
#Zig
Zig
const std = @import("std"); const c = @cImport({ @cInclude("stdlib.h"); // `free` @cInclude("string.h"); // `strdup` });   pub fn main() !void { const string = "Hello World!"; var copy = c.strdup(string);   try std.io.getStdOut().writer().print("{s}\n", .{copy}); c.free(copy); }
http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#Fortress
Fortress
  component call_a_function export Executable (* Declaring test functions that allow the various ways to call functions in Fortress to be demonstrated. *) addition(i:ZZ32, j:ZZ32): ZZ32 = i+j addition(i:ZZ32): ZZ32 = i+1   (* Strings are concatenated by using a space as an infix operator. *) addition(i:String, j:String): String = i j   printAString(s:String): () = println(s)   (* Functions can be passed to other functions as arguments. When passing a function as an argument, the argument's type should be represented as follows: "typeOfArgument(s)->returnType," which, in this case, is "String->()." You could also technically use the "Any" type, but that isn't type-safe. *) printAString(s:String, f:String->()) = f(s)   (* Defined functions can then be called as follows. *) var x:ZZ32 = addition(1, 2) var str:String = addition("This is ", "another string.")   run() = do (* You can call built-in functions the same way that you call functions that you define. *) println("x at start: " x)   x := addition(x, 2)   println("x at middle: " x)   printAString("This " "is " "a " "string.") printAString(str) printAString("\nThis is a string that is being printed by a function of the same name \nthat takes a function as an argument.\n", printAString)   x := addition(4)   println("x at end: " x) end end  
http://rosettacode.org/wiki/Catamorphism
Catamorphism
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value. Task Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language. See also Wikipedia article:   Fold Wikipedia article:   Catamorphism
#WDTE
WDTE
let a => import 'arrays'; let s => import 'stream'; let str => import 'strings';   # Sum of [1, 10]: let nums => [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]; a.stream nums -> s.reduce 0 + -- io.writeln io.stdout;   # As an alternative to an array, a range stream can be used. Here's the product of [1, 11): s.range 1 11 -> s.reduce 1 * -- io.writeln io.stdout;   # And here's a concatenation: s.range 1 11 -> s.reduce '' (str.format '{}{}') -- io.writeln io.stdout;
http://rosettacode.org/wiki/Catamorphism
Catamorphism
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value. Task Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language. See also Wikipedia article:   Fold Wikipedia article:   Catamorphism
#Wortel
Wortel
!/ ^+ [1 2 3] ; returns 6
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#Liberty_BASIC
Liberty BASIC
print "non-recursive version" print catNonRec(5) for i = 0 to 15 print i;" = "; catNonRec(i) next print   print "recursive version" print catRec(5) for i = 0 to 15 print i;" = "; catRec(i) next print   print "recursive with memoisation" redim cats(20) 'clear the array print catRecMemo(5) for i = 0 to 15 print i;" = "; catRecMemo(i) next print     wait   function catNonRec(n) 'non-recursive version catNonRec=1 for i=1 to n catNonRec=((2*((2*i)-1))/(i+1))*catNonRec next end function   function catRec(n) 'recursive version if n=0 then catRec=1 else catRec=((2*((2*n)-1))/(n+1))*catRec(n-1) end if end function   function catRecMemo(n) 'recursive version with memoisation if n=0 then catRecMemo=1 else if cats(n-1)=0 then 'call it recursively only if not already calculated prev = catRecMemo(n-1) else prev = cats(n-1) end if catRecMemo=((2*((2*n)-1))/(n+1))*prev end if cats(n) = catRecMemo 'memoisation for future use end function
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#PicoLisp
PicoLisp
(de braceExpand (Str) (let Lst (make (for (Lst (chop Str) Lst) (case (pop 'Lst) ("\\" (link (pop 'Lst))) ("{" (recur () (let L (make (while (case (pop 'Lst) ("\\" (link (pop 'Lst)) Lst) ("{" (recurse) Lst) ("}" NIL) ("," (link 0) Lst) # Replace commata with '0' (T (link @) Lst) ) ) ) (if (= "}" @) # Was closing brace (if (member 0 L) # Has comma(ta) (link (split L 0)) (chain (list "{") (replace L 0 ",") (list "}"))) (chain (list "{") (replace L 0 ",")) ) ) ) ) (T (link @)) ) ) ) (recur (Lst) (ifn (find pair Lst) (list (pack Lst)) (let R (recurse (cdr Lst)) (mapcan '((A) (mapcar '((B) (pack A B)) R)) (if (pair (car Lst)) (mapcan recurse (car Lst)) (list (car Lst)) ) ) ) ) ) ) )
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#Isabelle
Isabelle
theory Brazilian imports Main begin   function (sequential) base :: "nat ⇒ nat ⇒ nat list" where "base n 0 = undefined" | "base n (Suc 0) = replicate n 1" | "base n b = (if n < b then [n] else (base (n div b) b) @ [n mod b] )" by pat_completeness auto termination base apply(relation "measure (λ(n,b). n div b)", simp) using div_greater_zero_iff by auto   lemma base_simps: "b > 1 ⟹ base n b = (if n < b then [n] else base (n div b) b @ [n mod b])" by (metis One_nat_def base.elims nat_neq_iff not_less_zero)   lemma "base 123 10 = [1, 2, 3]" and "base 65536 2 = [1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]" and "base 65535 2 = [1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]" and "base 123 100 = [1, 23]" and "base 69 100 = [69]" and "base 255 16 = [15, 15]" by(simp add: base_simps)+   lemma "base 5 1 = [1, 1, 1, 1, 1]" by (simp add: eval_nat_numeral(3) numeral_Bit0)   lemma base_2_numbers: "a < b ⟹ c < b ⟹ a > 0 ⟹ base (a * b + c) b = [a, c]" apply(simp add: base_simps) using mult_eq_if by auto   lemma base_half_minus_one: "even n ⟹ n ≥ 8 ⟹ base n (n div 2 - 1) = [2, 2]" proof - assume "even n" and "n ≥ 8" have n: "(2 * (n div 2 - 1) + 2) = n" using ‹n ≥ 8› ‹even n› add.commute dvd_mult_div_cancel le_0_eq by auto from ‹n ≥ 8› base_2_numbers[where b="n div 2 - 1" and a=2 and c=2] have "base (2 * (n div 2 - 1) + 2) (n div 2 - 1) = [2, 2]" by simp with n show ?thesis by simp qed   lemma base_rs_numbers: "r > 0 ⟹ s - 1 > r ⟹ base (r*s) (s - 1) = [r, r]" proof - assume "r > 0" and "s - 1 > r" from ‹s - 1 > r› have "r*s = r*(s - 1) + r" by (metis add.commute gr_implies_not0 less_diff_conv mult.commute mult_eq_if) from base_2_numbers[where a=r and b="s - 1" and c=r] have "s - 1 > r ⟹ 0 < r ⟹ base (r * (s - 1) + r) (s - 1) = [r, r]" . with ‹s - 1 > r› ‹r > 0› have "base (r * (s - 1) + r) (s - 1) = [r, r]" by(simp) with ‹r * s = r * (s - 1) + r› show "base (r*s) (s - 1) = [r, r]" by (simp) qed   definition all_equal :: "nat list ⇒ bool" where "all_equal xs ≡ ∀x∈set xs. ∀y∈set xs. x = y"   lemma all_equal_alt: "all_equal xs ⟷ replicate (length xs) (hd xs) = xs" unfolding all_equal_def apply(induction xs) apply(simp) apply(simp) by (metis in_set_replicate replicate_eqI)   definition brazilian :: "nat set" where "brazilian ≡ {n. ∃b. 1 < b ∧ Suc b < n ∧ all_equal (base n b)}"     lemma "0 ∉ brazilian" and "1 ∉ brazilian" and "2 ∉ brazilian" and "3 ∉ brazilian" by (simp add: brazilian_def)+   lemma "4 ∉ brazilian" apply (simp add: brazilian_def all_equal_def) apply(intro allI impI) apply(case_tac "b = 1", simp) apply(case_tac "b = 2", simp add: base_simps, blast) by(simp)   lemma "5 ∉ brazilian" apply (simp add: brazilian_def all_equal_def) apply(intro allI impI) apply(case_tac "b = 1", simp) apply(case_tac "b = 2", simp add: base_simps, blast) apply(case_tac "b = 3", simp add: base_simps, blast) by(simp)   lemma "6 ∉ brazilian" apply (simp add: brazilian_def all_equal_def) apply(intro allI impI) apply(case_tac "b = 1", simp) apply(case_tac "b = 2", simp add: base_simps, blast) apply(case_tac "b = 3", simp add: base_simps, blast) apply(case_tac "b = 4", simp add: base_simps, blast) by(simp)   lemma "7 ∈ brazilian" apply(simp add: brazilian_def) apply(rule exI[where x=2]) by(simp add: base_simps all_equal_def)   lemma "8 ∈ brazilian" apply(simp add: brazilian_def) apply(rule exI[where x=3]) by(simp add: base_simps all_equal_def)   lemma "9 ∉ brazilian" apply (simp add: brazilian_def all_equal_def) apply(intro allI impI) apply(case_tac "b = 1", simp) apply(case_tac "b = 2", simp add: base_simps, blast) apply(case_tac "b = 3", simp add: base_simps, blast) apply(case_tac "b = 4", simp add: base_simps, blast) apply(case_tac "b = 5", simp add: base_simps, blast) apply(case_tac "b = 6", simp add: base_simps, blast) apply(case_tac "b = 7", simp add: base_simps, blast) by(simp)   theorem "even n ⟹ n ≥ 8 ⟹ n ∈ brazilian" apply(simp add: brazilian_def) apply(rule_tac x="n div 2 - 1" in exI) by(simp add: base_half_minus_one[simplified] all_equal_def)   (* The problem description on Rosettacode was broken. Fortunately, we found the error when proving it correct with Isabelle. Rosettacode claimed: "all integers, that factor decomposition is R*S >= 8, with S+1 > R, are Brazilian because R*S = R(S-1) + R, which is RR in base S-1" This is wrong. Here are some counterexamples:   r = 3 s = 3 r*s = 9 ≥ 8 s+1 = 4 > 3 = r But (s*r) = 9 ∉ brazilian   The correct precondition would be s-1>r instead of s+1>r.   But this is not enough.   Also, r > 1 is needed additionally, because r=1 s=9 r*s = 9 ≥ 8 s+1 = 10 > 1 = r or s-1 = 8 > 1 = r But (s*r) = 9 ∉ brazilian   Doing the proof, we also learn that the precondition r*s ≥ 8 is not required. *) theorem "r > 1 ⟹ s-1 > r ⟹ r*s ∈ brazilian" apply(simp add: brazilian_def) apply(rule_tac x="s - 1" in exI) apply(subst base_rs_numbers[of r s]) using not_numeral_le_zero apply fastforce apply(simp; fail) by(simp add: all_equal_def)     fun is_brazilian_for_base :: "nat ⇒ nat ⇒ bool" where "is_brazilian_for_base n 0 ⟷ False" | "is_brazilian_for_base n (Suc 0) ⟷ False" | "is_brazilian_for_base n (Suc b) ⟷ all_equal (base n (Suc b)) ∨ is_brazilian_for_base n b"   lemma "is_brazilian_for_base 7 2" and "is_brazilian_for_base 8 3" by code_simp+   lemma is_brazilian_for_base_Suc_simps: "is_brazilian_for_base n (Suc b) ⟷ b ≠ 0 ∧ (all_equal (base n (Suc b)) ∨ is_brazilian_for_base n b)" by(cases b)(simp)+   lemma is_brazilian_for_base: "is_brazilian_for_base n b ⟷ (∃w ∈ {2..b}. all_equal (base n w))" proof(induction b) case 0 show "is_brazilian_for_base n 0 = (∃w∈{2..0}. all_equal (base n w))" by simp next case (Suc b) assume IH: "is_brazilian_for_base n b = (∃w∈{2..b}. all_equal (base n w))" show "is_brazilian_for_base n (Suc b) = (∃w∈{2..Suc b}. all_equal (base n w))" apply(simp add: is_brazilian_for_base_Suc_simps IH) using le_Suc_eq by fastforce qed     lemma is_brazilian_for_base_is: "Suc (Suc n) ∈ brazilian ⟷ is_brazilian_for_base (Suc (Suc n)) n" apply(simp add: brazilian_def is_brazilian_for_base) using less_Suc_eq_le by force   definition brazilian_executable :: "nat ⇒ bool" where "brazilian_executable n ≡ n > 1 ∧ is_brazilian_for_base n (n - 2)"   lemma brazilian_executable[code_unfold]: "n ∈ brazilian ⟷ brazilian_executable n" apply(simp add: brazilian_executable_def) apply(cases "n = 0 ∨ n = 1") apply(simp add: brazilian_def) apply(blast) apply(simp) apply(case_tac n, simp, simp, rename_tac n2) apply(case_tac n2, simp, simp, rename_tac n3) apply(subst is_brazilian_for_base_is[symmetric]) apply(simp) done   text‹ In Isabelle/HOl, functions must be total, i.e. they must terminate. Therefore, we cannot simply write a function which enumerates the infinite set of natural numbers and stops when we found 20 Brazilian numbers, since it is not guaranteed that 20 Brazilian numbers exist and that the function will terminate. We could prove that and then write that function, but here is the lazy solution: ›   lemma "[n ← upt 0 34. n ∈ brazilian] = [7,8,10,12,13,14,15,16,18,20,21,22,24,26,27,28,30,31,32,33]" by(code_simp) lemma "[n ← upt 0 80. odd n ∧ n ∈ brazilian] = [7,13,15,21,27,31,33,35,39,43,45,51,55,57,63,65,69,73,75,77]" by code_simp   (*TODO: the first 20 prime Brazilian numbers*)   end
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#Gambas
Gambas
Public Sub Main()   Shell "cal 1969"   End
http://rosettacode.org/wiki/Brownian_tree
Brownian tree
Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a   Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere within the field. Where is not particularly important; it could be randomized, or it could be a fixed point. Particles are injected into the field, and are individually given a (typically random) motion pattern. When a particle collides with the seed or tree, its position is fixed, and it's considered to be part of the tree. Because of the lax rules governing the random nature of the particle's placement and motion, no two resulting trees are really expected to be the same, or even necessarily have the same general shape.
#Julia
Julia
using Images, FileIO   function main(h::Integer, w::Integer, side::Bool=false) W0 = w >> 1 H0 = h >> 1 @inline function motecolor(x::Integer, y::Integer) h = clamp(180 * (atan2(y - H0, x - W0) / π + 1.0), 0.0, 360.0) return HSV(h, 0.5, 0.5) end   img = zeros(RGB{N0f8}, h, w) img[H0, W0] = RGB(1, 1, 1) free = trues(h, w) free[H0, W0] = false for i in eachindex(img) x = rand(1:h) y = rand(1:w) free[x, y] || continue mc = motecolor(x, y) for j in 1:1000 xp = x + rand(-1:1) yp = y + rand(-1:1) contained = checkbounds(Bool, img, xp, yp) if contained && free[xp, yp] x, y = xp, yp continue else if side || (contained && !free[xp, yp]) free[x, y] = false img[x, y] = mc end break end end end return img end   imgnoside = main(256, 256) imgwtside = main(256, 256, true) save("data/browniantree_noside.jpg", imgnoside) save("data/browniantree_wtside.jpg", imgwtside)
http://rosettacode.org/wiki/Bulls_and_cows
Bulls and cows
Bulls and Cows Task Create a four digit random number from the digits   1   to   9,   without duplication. The program should:   ask for guesses to this number   reject guesses that are malformed   print the score for the guess The score is computed as: The player wins if the guess is the same as the randomly chosen number, and the program ends. A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number. A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position. Related tasks   Bulls and cows/Player   Guess the number   Guess the number/With Feedback   Mastermind
#EasyLang
EasyLang
dig[] = [ 1 2 3 4 5 6 7 8 9 ] for i range 4 h = i + random (9 - i) swap dig[i] dig[h] . # print dig[] len g[] 4 attempts = 0 repeat repeat ok = 0 s$[] = strchars input if len s$[] = 4 ok = 1 for i range 4 g[i] = number s$[i] if g[i] = 0 ok = 0 . . . until ok = 1 . print g[] attempts += 1 bulls = 0 cows = 0 for i range 4 if g[i] = dig[i] bulls += 1 else for j range 4 if dig[j] = g[i] cows += 1 . . . . print "bulls:" & bulls & " cows:" & cows until bulls = 4 . print "Well done! " & attempts & " attempts needed."
http://rosettacode.org/wiki/Caesar_cipher
Caesar cipher
Task Implement a Caesar cipher, both encoding and decoding. The key is an integer from 1 to 25. This cipher rotates (either towards left or right) the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "mono-alphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys. Caesar cipher is identical to Vigenère cipher with a key of length 1. Also, Rot-13 is identical to Caesar cipher with key 13. Related tasks Rot-13 Substitution Cipher Vigenère Cipher/Cryptanalysis
#CoffeeScript
CoffeeScript
cipher = (msg, rot) -> msg.replace /([a-z|A-Z])/g, ($1) -> c = $1.charCodeAt(0) String.fromCharCode \ if c >= 97 then (c + rot + 26 - 97) % 26 + 97 else (c + rot + 26 - 65) % 26 + 65   console.log cipher "Hello World", 2 console.log cipher "azAz %^&*()", 3
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Nim
Nim
const epsilon : float64 = 1.0e-15 var fact : int64 = 1 var e : float64 = 2.0 var e0 : float64 = 0.0 var n : int64 = 2   while abs(e - e0) >= epsilon: e0 = e fact = fact * n inc(n) e = e + 1.0 / fact.float64   echo e
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Pascal
Pascal
program Calculating_the_value_of_e; {$IFDEF FPC} {$MODE DELPHI} {$ENDIF}   {$IFDEF WINDOWS} {$APPTYPE CONSOLE} {$ENDIF} uses SysUtils;   const EPSILON = 1.0e-14;   function Get_E: Extended; var recfact: Extended; n: Integer; begin recfact := 1.0; Result := 2.0; n := 2; repeat recfact /= n; inc(n); Result := Result + recfact; until (recfact < EPSILON); end;   begin writeln(format('calc e = %.15f intern e= %.15f', [Get_E,exp(1.0)])); {$IFDEF WINDOWS}readln;{$ENDIF} end.  
http://rosettacode.org/wiki/Bulls_and_cows/Player
Bulls and cows/Player
Task Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts. One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list. Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring. Related tasks   Bulls and cows   Guess the number   Guess the number/With Feedback (Player)
#Red
Red
Red []   digits: charset [#"1" - #"9"]  ;; bitset for parse rule in valid function   check: function [s i ][  ;; returns string with bulls -B and cows - C found return sort append copy "" collect [ repeat pos 4 [ either ( v: pick i pos ) = pick s pos [ keep "B"][ if find s v [keep "C"] ] ] ] ]   valid: function [ i] [ all [ parse i [4 digits] "," 4 = length? unique i ] ]  ;; check if number/string is valid  ;; collect all possible permutations possible: collect [ repeat i 9876 [ if valid s: to-string i [ keep s ] ] ]  ;; should start at 1234, but for sake of brevity...   forever [  ;; read valid secret number from keyboard... while [ not valid secret: ask "^/Enter Number with 4 uniq digits (1 - 9 only, q-quit ) " ] [  ;; "^/" is character for newline either secret = "q" [print "Bye" halt ] [ print [ secret "invalid, Try again !" ] ] ]   results: copy #()  ;; map (key-value ) to store each guess and its result   foreach guess possible [ foreach [k v] body-of results [  ;; check guess against previous results if v <> check guess k [ guess: copy "" break ] ] if empty? guess [ continue ]  ;; check against previous results failed ? put results guess res: check guess secret  ;; store current guess and result in map if res = "BBBB" [break]  ;; number found  ? then break foreach loop ] foreach [k v] body-of results [ print [k "-" v]]  ;; display all guesses and their results print [CR "Found *" last k: keys-of results "* in " length? k " attempts" CR]  ;; cr - constant for newline / carriage return ] ;; forever loop  
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers
Calendar - for "REAL" programmers
Task Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented   entirely without lowercase. Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide. (Hint: manually convert the code from the Calendar task to all UPPERCASE) This task also is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." Moreover this task is further inspired by the long lost corollary article titled: "Real programmers think in UPPERCASE"! Note: Whereas today we only need to worry about ASCII, UTF-8, UTF-16, UTF-32, UTF-7 and UTF-EBCDIC encodings, in the 1960s having code in UPPERCASE was often mandatory as characters were often stuffed into 36-bit words as 6 lots of 6-bit characters. More extreme words sizes include 60-bit words of the CDC 6000 series computers. The Soviets even had a national character set that was inclusive of all 4-bit, 5-bit, 6-bit & 7-bit depending on how the file was opened... And one rogue Soviet university went further and built a 1.5-bit based computer. Of course... as us Boomers have turned into Geezers we have become HARD OF HEARING, and suffer from chronic Presbyopia, hence programming in UPPERCASE is less to do with computer architecture and more to do with practically. :-) For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. FYI: a nice ASCII art file of Snoopy can be found at textfiles.com. Save with a .txt extension. Trivia: The terms uppercase and lowercase date back to the early days of the mechanical printing press. Individual metal alloy casts of each needed letter, or punctuation symbol, were meticulously added to a press block, by hand, before rolling out copies of a page. These metal casts were stored and organized in wooden cases. The more often needed minuscule letters were placed closer to hand, in the lower cases of the work bench. The less often needed, capitalized, majuscule letters, ended up in the harder to reach upper cases.
#Tcl
Tcl
  \146\157\162\145\141\143\150 42 [\151\156\146\157 \143\157\155\155\141\156\144\163] { \145\166\141\154 " \160\162\157\143 [\163\164\162\151\156\147 \164\157\165\160\160\145\162 $42] {\141\162\147\163} \{ \163\145\164 \151 1 \146\157\162\145\141\143\150 \141 \$\141\162\147\163 \{ \151\146 \[\163\164\162\151\156\147 \155\141\164\143\150 _ \$\141\] \{\151\156\143\162 \151; \143\157\156\164\151\156\165\145\} \151\146 \$\151%2 \{\154\141\160\160\145\156\144 \156\141\162\147\163 \[\163\164\162\151\156\147 \164\157\154\157\167\145\162 \$\141\]\} \{\154\141\160\160\145\156\144 \156\141\162\147\163 \$\141\} \} \165\160\154\145\166\145\154 \"$42 \$\156\141\162\147\163\" \} " }   PROC _ CPUTS {L S} { UPVAR _ CAL CAL APPEND _ CAL($L) $S } PROC _ CENTER {S LN} { SET _ C [STRING LENGTH $S] SET _ L [EXPR _ ($LN-$C)/2]; SET _ R [EXPR _ $LN-$L-$C] FORMAT "%${L}S%${C}S%${R}S" _ "" $S "" } PROC _ CALENDAR {{YEAR 1969} {WIDTH 80}} { ARRAY SET CAL "" SET _ YRS [EXPR $YEAR-1584] SET _ SDAY [EXPR (6+$YRS+(($YRS+3)/4)-(($YRS-17)/100+1)+(($YRS+383)/400))%7] CPUTS 0 [CENTER "(SNOOPY)" [EXPR $WIDTH/25*25]]; CPUTS 1 "" CPUTS 2 [CENTER "--- $YEAR ---" [EXPR $WIDTH/25*25]]; CPUTS 3 "" FOR _ {SET _ NR 0} {$NR<=11} {INCR _ NR} { SET _ LINE [EXPR ($NR/($WIDTH/25))*8+4] SET _ NAME [LINDEX _ "JANUARY FEBRUARY MARCH APRIL MAY JUNE JULY AUGUST SEPTEMBER OCTOBER NOVEMBER DECEMBER" $NR] SET _ DAYS [EXPR 31-((($NR)%7)%2)-($NR==1)*(2-((($YEAR%4==0)&&($YEAR%100>0))||($YEAR%400==0)))] CPUTS $LINE "[CENTER $NAME 20] " CPUTS [INCR _ LINE] "MO TU WE TH FR SA SU "; INCR _ LINE SET _ DAY [EXPR 1-$SDAY] FOR _ {SET _ X 0} {$X<42} {INCR _ X} { IF _ ($DAY>0)&&($DAY<=$DAYS) {CPUTS $LINE [FORMAT "%2d " $DAY]} {CPUTS $LINE " "} IF _ (($X+1)%7)==0 {CPUTS $LINE " "; INCR _ LINE} INCR _ DAY } SET _ SDAY [EXPR ($SDAY+($DAYS%7))%7] } FOR _ {SET _ X 0} {$X<[ARRAY SIZE _ CAL]} {INCR _ X} { PUTS _ $CAL($X) } }   CALENDAR  
http://rosettacode.org/wiki/Call_a_foreign-language_function
Call a foreign-language function
Task Show how a foreign language function can be called from the language. As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can be copied if necessary. Get the result from strdup and print it using language means. Do not forget to free the result of strdup (allocated in the heap). Notes It is not mandated if the C run-time library is to be loaded statically or dynamically. You are free to use either way. C++ and C solutions can take some other language to communicate with. It is not mandatory to use strdup, especially if the foreign function interface being demonstrated makes that uninformative. See also   Use another language to call a function
#zkl
zkl
//-*-c-*- // flf.c, Call a foreign-language function   // export zklRoot=/home/ZKL // clang -O -fPIC -I $zklRoot/VM -c -o flf.o flf.c // clang flf.o -L$zklRoot/Lib -lzkl -shared -Wl,-soname,flf.so -o flf.so   #include <string.h>   #include "zklObject.h" #include "zklMethod.h" #include "zklString.h" #include "zklImports.h"   // strlen(str) static Instance *zkl_strlen(Instance *_,pArglist arglist,pVM vm) { Instance *s = arglistGetString(arglist,0,"strlen",vm); size_t sz = strlen(stringText(s)); return intCreate(sz,vm); }   static int one;   DllExport void *construct(void *vm) { if (!vm) return (void *)ZKLX_PROTOCOL; // handshake // If this is reloaded, nothing happens except // construct() is called again so don't reinitialize if (!one) // static items are zero { // do some one time initialization one = 1; } return methodCreate(Void,0,zkl_strlen,vm); }
http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#FreeBASIC
FreeBASIC
  Sub Saludo() Print "Hola mundo!" End Sub   Function Copialo(txt As String, siNo As Short, final As String = "") As String Dim nuevaCadena As String   For cont As Short = 1 To siNo nuevaCadena &= txt Next   Return Trim(nuevaCadena) & final End Function   Sub testNumeros(a As Integer, b As Integer, c As Integer = 0) Print a, b, c End Sub   Sub testCadenas(txt As String) For cont As Byte = 0 To Len(txt) Print Chr(txt[cont]); ""; Next cont End Sub   Saludo Print Copialo("Saludos ", 6) Print Copialo("Saludos ", 3, "!!") ? testNumeros(1, 2, 3) testNumeros(1, 2) ? testCadenas("1, 2, 3, 4, cadena, 6, 7, 8, \'incluye texto\'")  
http://rosettacode.org/wiki/Catamorphism
Catamorphism
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value. Task Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language. See also Wikipedia article:   Fold Wikipedia article:   Catamorphism
#Wren
Wren
var a = [1, 2, 3, 4, 5] var sum = a.reduce { |acc, i| acc + i } var prod = a.reduce { |acc, i| acc * i } var sumSq = a.reduce { |acc, i| acc + i*i } System.print(a) System.print("Sum is %(sum)") System.print("Product is %(prod)") System.print("Sum of squares is %(sumSq)")
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#Logo
Logo
to factorial :n output ifelse [less? :n 1] 1 [product :n factorial difference :n 1] end to choose :n :r output quotient factorial :n product factorial :r factorial difference :n :r end to catalan :n output product (quotient sum :n 1) choose product 2 :n :n end   repeat 15 [print catalan repcount]
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#PowerShell
PowerShell
  function Expand-Braces ( [string]$String ) { $Escaped = $False $Stack = New-Object System.Collections.Stack $ClosedBraces = $BracesToParse = $Null   ForEach ( $i in 0..($String.Length-1) ) { Switch ( $String[$i] ) { '\' { $Escaped = -not $Escaped break }   '{' { If ( -not $Escaped ) { $Stack.Push( [pscustomobject]@{ Delimiters = @( $i ) } ) } }   ',' { If ( -not $Escaped -and $Stack.Count ) { $Stack.Peek().Delimiters += $i } }   '}' { If ( -not $Escaped -and $Stack.Count ) { $Stack.Peek().Delimiters += $i $ClosedBraces = $Stack.Pop() If ( $ClosedBraces.Delimiters.Count -gt 2 ) { $BracesToParse = $ClosedBraces } } }   default { $Escaped = $False } } }   If ( $BracesToParse ) { $Start = $String.Substring( 0, $BracesToParse.Delimiters[0] ) $End = $String.Substring( $BracesToParse.Delimiters[-1] + 1 )   ForEach ( $i in 0..($BracesToParse.Delimiters.Count-2) ) { $Option = $String.Substring( $BracesToParse.Delimiters[$i] + 1, $BracesToParse.Delimiters[$i+1] - $BracesToParse.Delimiters[$i] - 1 ) Expand-Braces ( $Start + $Option + $End ) } } Else { $String } }  
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#J
J
  Doc=: conjunction def 'u :: (n"_)'   brazilian=: (1 e. (#@~.@(#.^:_1&>)~ (2 + [: (i.) _3&+)))&> Doc 'brazilian y NB. is 1 if y is brazilian, else 0'   Filter=: (#~`)(`:6)     B=: brazilian Filter 4 + i. 300 NB. gather Brazilion numbers less than 304   20 {. B NB. first 20 Brazilion numbers 7 8 10 12 13 14 15 16 18 20 21 22 24 26 27 28 30 31 32 33   odd =: 1 = 2&|   20 {. odd Filter B NB. first 20 odd Brazilion numbers 7 13 15 21 27 31 33 35 39 43 45 51 55 57 63 65 69 73 75 77   prime=: 1&p:   20 {. prime Filter B NB. uh oh need a new technique 7 13 31 43 73 127 157 211 241 0 0 0 0 0 0 0 0 0 0 0   NB. p: y is the yth prime, with 2 being prime 0 20 {. brazilian Filter p: 2 + i. 500 7 13 31 43 73 127 157 211 241 307 421 463 601 757 1093 1123 1483 1723 2551 2801  
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#Go
Go
package main   import ( "fmt" "time" )   const pageWidth = 80   func main() { printCal(1969) }   func printCal(year int) { thisDate := time.Date(year, 1, 1, 1, 1, 1, 1, time.UTC) var ( dayArr [12][7][6]int // month, weekday, week month, lastMonth time.Month weekInMonth, dayInMonth int ) for thisDate.Year() == year { if month = thisDate.Month(); month != lastMonth { weekInMonth = 0 dayInMonth = 1 } weekday := thisDate.Weekday() if weekday == 0 && dayInMonth > 1 { weekInMonth++ } dayArr[int(month)-1][weekday][weekInMonth] = thisDate.Day() lastMonth = month dayInMonth++ thisDate = thisDate.Add(time.Hour * 24) } centre := fmt.Sprintf("%d", pageWidth/2) fmt.Printf("%"+centre+"s\n\n", "[SNOOPY]") centre = fmt.Sprintf("%d", pageWidth/2-2) fmt.Printf("%"+centre+"d\n\n", year) months := [12]string{ " January ", " February", " March ", " April ", " May ", " June ", " July ", " August ", "September", " October ", " November", " December"} days := [7]string{"Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"} for qtr := 0; qtr < 4; qtr++ { for monthInQtr := 0; monthInQtr < 3; monthInQtr++ { // Month names fmt.Printf("  %s ", months[qtr*3+monthInQtr]) } fmt.Println() for monthInQtr := 0; monthInQtr < 3; monthInQtr++ { // Day names for day := 0; day < 7; day++ { fmt.Printf(" %s", days[day]) } fmt.Printf(" ") } fmt.Println() for weekInMonth = 0; weekInMonth < 6; weekInMonth++ { for monthInQtr := 0; monthInQtr < 3; monthInQtr++ { for day := 0; day < 7; day++ { if dayArr[qtr*3+monthInQtr][day][weekInMonth] == 0 { fmt.Printf(" ") } else { fmt.Printf("%3d", dayArr[qtr*3+monthInQtr][day][weekInMonth]) } } fmt.Printf(" ") } fmt.Println() } fmt.Println() } }
http://rosettacode.org/wiki/Brownian_tree
Brownian tree
Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a   Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere within the field. Where is not particularly important; it could be randomized, or it could be a fixed point. Particles are injected into the field, and are individually given a (typically random) motion pattern. When a particle collides with the seed or tree, its position is fixed, and it's considered to be part of the tree. Because of the lax rules governing the random nature of the particle's placement and motion, no two resulting trees are really expected to be the same, or even necessarily have the same general shape.
#Kotlin
Kotlin
// version 1.1.2   import java.awt.Graphics import java.awt.image.BufferedImage import java.util.* import javax.swing.JFrame   class BrownianTree : JFrame("Brownian Tree"), Runnable { private val img: BufferedImage private val particles = LinkedList<Particle>()   private companion object { val rand = Random() }   private inner class Particle { private var x = rand.nextInt(img.width) private var y = rand.nextInt(img.height)   /* returns true if either out of bounds or collided with tree */ fun move(): Boolean { val dx = rand.nextInt(3) - 1 val dy = rand.nextInt(3) - 1 if ((x + dx < 0) || (y + dy < 0) || (y + dy >= img.height) || (x + dx >= img.width)) return true x += dx y += dy if ((img.getRGB(x, y) and 0xff00) == 0xff00) { img.setRGB(x - dx, y - dy, 0xff00) return true } return false } }   init { setBounds(100, 100, 400, 300) defaultCloseOperation = EXIT_ON_CLOSE img = BufferedImage(width, height, BufferedImage.TYPE_INT_RGB) img.setRGB(img.width / 2, img.height / 2, 0xff00) }   override fun paint(g: Graphics) { g.drawImage(img, 0, 0, this) }   override fun run() { (0 until 20000).forEach { particles.add(Particle()) }   while (!particles.isEmpty()) { val iter = particles.iterator() while (iter.hasNext()) { if (iter.next().move()) iter.remove() } repaint() } } }   fun main(args: Array<String>) { val b = BrownianTree() b.isVisible = true Thread(b).start() }
http://rosettacode.org/wiki/Bulls_and_cows
Bulls and cows
Bulls and Cows Task Create a four digit random number from the digits   1   to   9,   without duplication. The program should:   ask for guesses to this number   reject guesses that are malformed   print the score for the guess The score is computed as: The player wins if the guess is the same as the randomly chosen number, and the program ends. A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number. A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position. Related tasks   Bulls and cows/Player   Guess the number   Guess the number/With Feedback   Mastermind
#Eiffel
Eiffel
  class BULLS_AND_COWS   create execute   feature   execute -- Initiate game. do io.put_string ("Let's play bulls and cows.%N") create answer.make_empty play end   feature {NONE}   play -- Plays bulls ans cows. local count, seed: INTEGER guess: STRING do from until seed > 0 loop io.put_string ("Enter a positive integer.%NYour play will be generated from it.%N") io.read_integer seed := io.last_integer end generate_answer (seed) io.put_string ("Your game has been created.%N Try to guess the four digit number.%N") create guess.make_empty from until guess ~ answer loop io.put_string ("Guess: ") io.read_line guess := io.last_string if guess.count = 4 and guess.is_natural and not guess.has ('0') then io.put_string (score (guess) + "%N") count := count + 1 else io.put_string ("Your input does not have the correct format.") end end io.put_string ("Congratulations! You won with " + count.out + " guesses.") end   answer: STRING   generate_answer (s: INTEGER) -- Answer with 4-digits between 1 and 9 stored in 'answer'. require positive_seed: s > 0 local random: RANDOM ran: INTEGER do create random.set_seed (s) from until answer.count = 4 loop ran := (random.double_item * 10).floor if ran > 0 and not answer.has_substring (ran.out) then answer.append (ran.out) end random.forth end ensure answer_not_void: answer /= Void correct_length: answer.count = 4 end   score (g: STRING): STRING -- Score for the guess 'g' depending on 'answer'. require same_length: answer.count = g.count local k: INTEGER a, ge: STRING do Result := "" a := answer.twin ge := g.twin across 1 |..| a.count as c loop if a [c.item] ~ ge [c.item] then Result := Result + "BULL " a [c.item] := ' ' ge [c.item] := ' ' end end across 1 |..| a.count as c loop if a [c.item] /= ' ' then k := ge.index_of (a [c.item], 1) if k > 0 then Result := Result + "COW " ge [k] := ' ' end end end end   end  
http://rosettacode.org/wiki/Caesar_cipher
Caesar cipher
Task Implement a Caesar cipher, both encoding and decoding. The key is an integer from 1 to 25. This cipher rotates (either towards left or right) the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "mono-alphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys. Caesar cipher is identical to Vigenère cipher with a key of length 1. Also, Rot-13 is identical to Caesar cipher with key 13. Related tasks Rot-13 Substitution Cipher Vigenère Cipher/Cryptanalysis
#Commodore_BASIC
Commodore BASIC
1 rem caesar cipher 2 rem rosetta code 10 print chr$(147);chr$(14); 15 input "Enter a key value from 1 to 25";kv 20 if kv<1 or kv>25 then print "Out of range.":goto 15 25 gosub 1000 30 print chr$(147);"Enter a message to translate." 35 print:print "Press CTRL-Z when finished.":print 40 mg$="":gosub 2000 45 print chr$(147);"Processing...":gosub 3000 50 print chr$(147);"The translated message is:" 55 print:print cm$ 100 print:print "Do another one? "; 110 get k$:if k$<>"y" and k$<>"n" then 110 120 print k$:if k$="y" then goto 10 130 end   1000 rem generate encoding table 1010 ec$="" 1015 rem lower case 1020 for i=kv to 26:ec$=ec$+chr$(i+64):next i 1021 for i=1 to kv-1:ec$=ec$+chr$(i+64):next i 1025 rem upper case 1030 for i=kv to 26:ec$=ec$+chr$(i+192):next i 1031 for i=1 to kv-1:ec$=ec$+chr$(i+192):next i 1099 return   2000 rem get user input routine 2005 print chr$(18);" ";chr$(146);chr$(157); 2010 get k$:if k$="" then 2010 2012 if k$=chr$(13) then print " ";chr$(157); 2015 print k$; 2020 if k$=chr$(20) then mg$=left$(mg$,len(mg$)-1):goto 2040 2025 if len(mg$)=255 or k$=chr$(26) then return 2030 mg$=mg$+k$ 2040 goto 2005   3000 rem translate message 3005 cm$="" 3010 for i=1 to len(mg$) 3015 c=asc(mid$(mg$,i,1)) 3020 if c<65 or (c>90 and c<193) or c>218 then cm$=cm$+chr$(c):goto 3030 3025 if c>=65 and c<=90 then c=c-64 3030 if c>=193 and c<=218 then c=(c-192)+26 3035 cm$=cm$+mid$(ec$,c,1) 3040 next i 3050 return
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Perl
Perl
use bignum qw(e);   $e = 2; $f = 1; do { $e0 = $e; $n++; $f *= 2*$n * (1 + 2*$n); $e += (2*$n + 2) / $f; } until ($e-$e0) < 1.0e-39;   print "Computed " . substr($e, 0, 41), "\n"; print "Built-in " . e, "\n";
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Phix
Phix
with javascript_semantics atom e0 = 0, e = 2, n = 0, fact = 1 while abs(e-e0)>=1e-15 do e0 = e n += 1 fact *= 2*n*(2*n+1) e += (2*n+2)/fact end while printf(1,"Computed e = %.15f\n",e) printf(1," Real e = %.15f\n",E) printf(1," Error = %g\n",E-e) printf(1,"Number of iterations = %d\n",n)
http://rosettacode.org/wiki/Bulls_and_cows/Player
Bulls and cows/Player
Task Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts. One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list. Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring. Related tasks   Bulls and cows   Guess the number   Guess the number/With Feedback (Player)
#REXX
REXX
/*REXX program plays the Bulls & Cows game with CBLFs (Carbon Based Life Forms). */ parse arg ? .; if datatype(?,'W') then call random ,,? /*Random seed? Make repeatable*/ L=1234; H=9876; call gen@ /*generate all possibilities. */ do forever; g=random(L,H); if @.g\==. then leave /*obtain a random 1st guess. */ end /*forever*/ /* [↑] obtain rand 1st guess.*/ $$1= '───── How many bulls and cows were guessed with '; $$2=" ? [─── or QUIT]" do until #()<2 | bull==4; say; call ask /*examine @ list; get answer.*/ do ?=L to H; if @.?==. then iterate /*is this already eliminated ?*/ call bull#  ?,g /*obtain bulls and cows count.*/ if bull\==bulls | cow\==cows then @.?=. /*eliminate this possibility. */ end /*?*/ end /*until*/   if #==0 then do; call serr "At least one of your responses was invalid."; exit; end say; say " ╔═════════════════════════════════════════════════╗" say " ║ ║" say " ║ Your secret Bulls and Cows number is: " g " ║" say " ║ ║" say " ╚═════════════════════════════════════════════════╝"; say exit /*stick a fork in it, we're all done. */ /*──────────────────────────────────────────────────────────────────────────────────────*/ #: #=0; do k=L to H; if @.k==. then iterate; #=#+1; g=k; end; return # gen@: @.=.; do j=L to H; if \rep() & pos(0, j)==0 then @.j=j; end; return rep: do k=1 for 3; if pos(substr(j, k, 1), j, k+1)\==0 then return 1; end; return 0 serr: say; say '───── ***error*** '  ! arg(1); return /*──────────────────────────────────────────────────────────────────────────────────────*/ bull#: parse arg n,q; w=length(n); bulls=0 /*W: # digits in N; bull cntr=0 */ do j=1 for w; if substr(n, j, 1) \== substr(q, j, 1) then iterate bulls=bulls+1; q=overlay(., q, j) /*bump counter; disallow for cow*/ end /*j*/ /* [↑] bull count═══════════════*/ cows=0 /*set the number of cows to zero.*/ do k=1 for w; _=substr(n, k, 1); if pos(_, q)==0 then iterate cows=cows + 1; q=translate(q, , _) /*bump counter; allow multiple #*/ end /*k*/ /* [↑] cow count═══════════════*/ return /*──────────────────────────────────────────────────────────────────────────────────────*/ ask: do forever; say $$1 g $$2; pull x 1 bull cow . /*display prompt; obtain answer.*/ select /* [↑] PULL capitalizes the args*/ when abbrev('QUIT', x, 1) then exit /*the user wants to quit playing.*/ when bull == '' then != "no numbers were entered." when cow == '' then != "not enough numbers were entered." when words(x) > 2 then != "too many numbers entered: " x when \datatype(bull, 'W') then != "1st number (bulls) not an integer: " bull when \datatype(cow , 'W') then != "2nd number (cows) not an integer: " cow when bull <0 | bull >4 then != "1st number (bulls) not 0 ──► 4: " bull when cow <0 | cow >4 then != "2nd number (cows) not 0 ──► 4: " cow when bull + cow > 4 then != "sum of bulls and cows can't be > 4: " x otherwise  != end /*select*/ if !\=='' then do; call serr; iterate; end /*prompt the user and try again. */ bull=bull/1; cow=cow/1; return /*normalize bulls & cows numbers.*/ end /*forever*/
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers
Calendar - for "REAL" programmers
Task Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented   entirely without lowercase. Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide. (Hint: manually convert the code from the Calendar task to all UPPERCASE) This task also is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." Moreover this task is further inspired by the long lost corollary article titled: "Real programmers think in UPPERCASE"! Note: Whereas today we only need to worry about ASCII, UTF-8, UTF-16, UTF-32, UTF-7 and UTF-EBCDIC encodings, in the 1960s having code in UPPERCASE was often mandatory as characters were often stuffed into 36-bit words as 6 lots of 6-bit characters. More extreme words sizes include 60-bit words of the CDC 6000 series computers. The Soviets even had a national character set that was inclusive of all 4-bit, 5-bit, 6-bit & 7-bit depending on how the file was opened... And one rogue Soviet university went further and built a 1.5-bit based computer. Of course... as us Boomers have turned into Geezers we have become HARD OF HEARING, and suffer from chronic Presbyopia, hence programming in UPPERCASE is less to do with computer architecture and more to do with practically. :-) For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. FYI: a nice ASCII art file of Snoopy can be found at textfiles.com. Save with a .txt extension. Trivia: The terms uppercase and lowercase date back to the early days of the mechanical printing press. Individual metal alloy casts of each needed letter, or punctuation symbol, were meticulously added to a press block, by hand, before rolling out copies of a page. These metal casts were stored and organized in wooden cases. The more often needed minuscule letters were placed closer to hand, in the lower cases of the work bench. The less often needed, capitalized, majuscule letters, ended up in the harder to reach upper cases.
#UNIX_Shell
UNIX Shell
CAL=CAL TR=TR A=A Z=Z LANG=C ${CAL,,} 1969 | ${TR,,} ${A,}-${Z,} A-Z
http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#Free_Pascal
Free Pascal
Public Sub Main()   Hello Print CopyIt("Hello ", 6) Print CopyIt("Hello ", 3, "!!")   End '_____________________________________________________________________________________ Public Sub CopyIt(sString As String, siNo As Short, Optional sEnd As String) As String Dim siCount As Short Dim sNewString As String   For siCount = 1 To siNo sNewString &= sString Next   Return Trim(sNewString) & sEnd   End '_____________________________________________________________________________________ Public Sub Hello()   Print "Hello world!"   End
http://rosettacode.org/wiki/Catamorphism
Catamorphism
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value. Task Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language. See also Wikipedia article:   Fold Wikipedia article:   Catamorphism
#zkl
zkl
T("foo","bar").reduce(fcn(p,n){p+n}) //--> "foobar" "123four5".reduce(fcn(p,c){p+(c.matches("[0-9]") and c or 0)}, 0) //-->11 File("foo.zkl").reduce('+(1).fpM("0-"),0) //->5 (lines in file)
http://rosettacode.org/wiki/Catamorphism
Catamorphism
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value. Task Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language. See also Wikipedia article:   Fold Wikipedia article:   Catamorphism
#ZX_Spectrum_Basic
ZX Spectrum Basic
10 DIM a(5) 20 FOR i=1 TO 5 30 READ a(i) 40 NEXT i 50 DATA 1,2,3,4,5 60 LET o$="+": GO SUB 1000: PRINT tmp 70 LET o$="-": GO SUB 1000: PRINT tmp 80 LET o$="*": GO SUB 1000: PRINT tmp 90 STOP 1000 REM Reduce 1010 LET tmp=a(1) 1020 FOR i=2 TO 5 1030 LET tmp=VAL ("tmp"+o$+"a(i)") 1040 NEXT i 1050 RETURN
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#Lua
Lua
-- recursive with memoization catalan = {[0] = 1} setmetatable(catalan, { __index = function(c, n) c[n] = c[n-1]*2*(2*n-1)/(n+1) return c[n] end } )   for i=0,14 do print(catalan[i]) end
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#Prolog
Prolog
  sym(',', commalist) --> ['\\',','], !. sym(H, Context) --> [H], { not(H = '{'; H = '}'), (Context = commalist -> not(H = ','); true) }. syms([H|T], Context) --> sym(H, Context), !, syms(T, Context). syms([], _) --> []. symbol(Symbol, Context) --> syms(Syms,Context), {atom_chars(Symbol, Syms)}.   braces(Member) --> ['{'], commalist(List), ['}'], {length(List, Len), Len > 1, member(Member, List)}.   commalist([H|T]) --> sym_braces(H, commalist), [','], commalist(T). commalist([H]) --> sym_braces(H, commalist).   sym_braces(String, Context) --> symbol(S1, Context), braces(S2), sym_braces(S3, Context), {atomics_to_string([S1,S2,S3],String)}. sym_braces(String, Context) --> braces(S1), symbol(S2, Context), sym_braces(S3, Context), {atomics_to_string([S1,S2,S3],String)}. sym_braces(String, Context) --> symbol(String, Context). sym_braces(String, _) --> braces(String). sym_braces(String, Context) --> ['{'], sym_braces(S2, Context), {atomics_to_string(['{',S2],String)}. sym_braces(String, Context) --> ['}'], sym_braces(S2, Context), {atomics_to_string(['}',S2],String)}.   grammar(String) --> sym_braces(String, braces).   brace_expansion(In, Out) :- atom_chars(In, Chars), findall(Out,grammar(Out, Chars, []), List), list_to_set(List, Out).  
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#Java
Java
import java.math.BigInteger; import java.util.List;   public class Brazilian { private static final List<Integer> primeList = List.of( 2, 3, 5, 7, 9, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 169, 173, 179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 233, 239, 241, 247, 251, 257, 263, 269, 271, 277, 281, 283, 293, 299, 307, 311, 313, 317, 331, 337, 347, 349, 353, 359, 367, 373, 377, 379, 383, 389, 397, 401, 403, 409, 419, 421, 431, 433, 439, 443, 449, 457, 461, 463, 467, 479, 481, 487, 491, 499, 503, 509, 521, 523, 533, 541, 547, 557, 559, 563, 569, 571, 577, 587, 593, 599, 601, 607, 611, 613, 617, 619, 631, 641, 643, 647, 653, 659, 661, 673, 677, 683, 689, 691, 701, 709, 719, 727, 733, 739, 743, 751, 757, 761, 767, 769, 773, 787, 793, 797, 809, 811, 821, 823, 827, 829, 839, 853, 857, 859, 863, 871, 877, 881, 883, 887, 907, 911, 919, 923, 929, 937, 941, 947, 949, 953, 967, 971, 977, 983, 991, 997 );   public static boolean isPrime(int n) { if (n < 2) { return false; }   for (Integer prime : primeList) { if (n == prime) { return true; } if (n % prime == 0) { return false; } if (prime * prime > n) { return true; } }   BigInteger bi = BigInteger.valueOf(n); return bi.isProbablePrime(10); }   private static boolean sameDigits(int n, int b) { int f = n % b; while ((n /= b) > 0) { if (n % b != f) { return false; } } return true; }   private static boolean isBrazilian(int n) { if (n < 7) return false; if (n % 2 == 0) return true; for (int b = 2; b < n - 1; ++b) { if (sameDigits(n, b)) { return true; } } return false; }   public static void main(String[] args) { for (String kind : List.of("", "odd ", "prime ")) { boolean quiet = false; int bigLim = 99_999; int limit = 20; System.out.printf("First %d %sBrazilian numbers:\n", limit, kind); int c = 0; int n = 7; while (c < bigLim) { if (isBrazilian(n)) { if (!quiet) System.out.printf("%d ", n); if (++c == limit) { System.out.println("\n"); quiet = true; } } if (quiet && !"".equals(kind)) continue; switch (kind) { case "": n++; break; case "odd ": n += 2; break; case "prime ": do { n += 2; } while (!isPrime(n)); break; default: throw new AssertionError("Oops"); } } if ("".equals(kind)) { System.out.printf("The %dth Brazilian number is: %d\n\n", bigLim + 1, n); } } } }
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#Haskell
Haskell
import qualified Data.Text as T import Data.Time import Data.Time.Calendar import Data.Time.Calendar.WeekDate import Data.List.Split (chunksOf) import Data.List   data Day = Su | Mo | Tu | We | Th | Fr | Sa deriving (Show, Eq, Ord, Enum)   data Month = January | February | March | April | May | June | July | August | September | October | November | December deriving (Show, Eq, Ord, Enum)   monthToInt :: Month -> Int monthToInt = (+ 1) . fromEnum   dayFromDate :: Integer -> Month -> Int -> Int dayFromDate year month day = day' `mod` 7 where (_, _, day') = toWeekDate $ fromGregorian year (monthToInt month) day   nSpaces :: Int -> T.Text nSpaces n = T.replicate n (T.pack " ")   space :: T.Text space = nSpaces 1   calMarginWidth = 3   calMargin :: T.Text calMargin = nSpaces calMarginWidth   calWidth = 20   listMonth :: Integer -> Month -> [T.Text] listMonth year month = [monthHeader, weekHeader] ++ weeks' where monthHeader = (T.center calWidth ' ') . T.pack $ show month   weekHeader = (T.intercalate space) $ map (T.pack . show) [(Su)..]   monthLength = toInteger $ gregorianMonthLength year $ monthToInt month   firstDay = dayFromDate year month 1   days = replicate firstDay (nSpaces 2) ++ map ((T.justifyRight 2 ' ') . T.pack . show) [1..monthLength]   weeks = map (T.justifyLeft calWidth ' ') $ map (T.intercalate space) $ chunksOf 7 days   weeks' = weeks ++ replicate (6 - length weeks) (nSpaces calWidth)   listCalendar :: Integer -> Int -> [[[T.Text]]] listCalendar year calColumns = (chunksOf calColumns) . (map (listMonth year)) $ enumFrom January   calColFromCol :: Int -> Int calColFromCol columns = c + if r >= calWidth then 1 else 0 where (c, r) = columns `divMod` (calWidth + calMarginWidth)   colFromCalCol :: Int -> Int colFromCalCol calCol = calCol * calWidth + ((calCol - 1) * calMarginWidth)   center :: Int -> String -> String center i a = T.unpack . (T.center i ' ') $ T.pack a   printCal :: [[[T.Text]]] -> IO () printCal = mapM_ f where f c = mapM_ (putStrLn . T.unpack) rows where rows = map (T.intercalate calMargin) $ transpose c   printCalendar :: Integer -> Int -> IO () printCalendar year columns = if columns < 20 then putStrLn $ "Cannot print less than 20 columns" else do putStrLn $ center columns' "[Maybe Snoopy]" putStrLn $ center columns' $ show year putStrLn "" printCal $ listCalendar year calcol' where calcol' = calColFromCol columns   columns' = colFromCalCol calcol'
http://rosettacode.org/wiki/Brownian_tree
Brownian tree
Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a   Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere within the field. Where is not particularly important; it could be randomized, or it could be a fixed point. Particles are injected into the field, and are individually given a (typically random) motion pattern. When a particle collides with the seed or tree, its position is fixed, and it's considered to be part of the tree. Because of the lax rules governing the random nature of the particle's placement and motion, no two resulting trees are really expected to be the same, or even necessarily have the same general shape.
#Liberty_BASIC
Liberty BASIC
'[RC]Brownian motion tree nomainwin dim screen(600,600) WindowWidth = 600 WindowHeight = 600 open "Brownian" for graphics_nsb_nf as #1 #1 "trapclose [quit]" #1 "down ; fill blue" rad=57.29577951 particles=500   'draw starting circle and mid point for n= 1 to 360 x=300-(200*sin(n/rad)) y=300-(200*cos(n/rad)) #1, "color white ; set ";x;" ";y screen(x,y)=1 next n #1, "color white ; set 300 300" screen(300,300)=1   'set up initial particles dim particle(particles,9)'x y deltax deltay rotx roty for n = 1 to particles gosub [randomparticle] next   'start timed drawing loop timer 17, [draw] wait     [draw] #1 "discard" scan for n = 1 to particles oldx=particle(n,1) oldy=particle(n,2)   'erase particle if not(screen(oldx,oldy)) then #1 "color blue ; set ";oldx;" ";oldy end if   'move particle x particle(n,1)=particle(n,1)+int((sin(particle(n,6)/rad)*10)+particle(n,3)) particle(n,5)=particle(n,5)+6 mod 360 if particle(n,1)>599 or particle(n,1)<1 then gosub [randomparticle]   'move particle y particle(n,2)=particle(n,2)+int((sin(particle(n,5)/rad)*10)+particle(n,4)) particle(n,6)=particle(n,6)+6 mod 360 if particle(n,2)>599 or particle(n,2)<1 then gosub [randomparticle]   'checkhit x=particle(n,1) y=particle(n,2) if screen(x-1,y-1) or screen(x-1,y) or screen(x-1,y+1)_ or screen(x,y-1) or screen(x,y) or screen(x,y+1)_ or screen(x+1,y-1) or screen(x+1,y) or screen(x+1,y+1) then #1 "color white ; set ";particle(n,1);" ";particle(n,2) screen(particle(n,1),particle(n,2))=1 else #1 "color red ; set ";particle(n,1);" ";particle(n,2) end if next wait       [randomparticle] particle(n,1)=int(rnd(0)*599)+1 particle(n,2)=int(rnd(0)*599)+1 particle(n,3)=int(2-rnd(0)*4) particle(n,4)=int(2-rnd(0)*4) particle(n,5)=int(rnd(0)*360) particle(n,6)=int(rnd(0)*360) return   [quit] timer 0 close #1 end
http://rosettacode.org/wiki/Bulls_and_cows
Bulls and cows
Bulls and Cows Task Create a four digit random number from the digits   1   to   9,   without duplication. The program should:   ask for guesses to this number   reject guesses that are malformed   print the score for the guess The score is computed as: The player wins if the guess is the same as the randomly chosen number, and the program ends. A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number. A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position. Related tasks   Bulls and cows/Player   Guess the number   Guess the number/With Feedback   Mastermind
#Elena
Elena
import system'routines; import extensions;   class GameMaster { object theNumbers; object theAttempt;   constructor() { // generate secret number var randomNumbers := new int[]{1,2,3,4,5,6,7,8,9}.randomize(9);   theNumbers := randomNumbers.Subarray(0, 4); theAttempt := new Integer(1); }   ask() { var row := console.print("Your Guess #",theAttempt," ?").readLine();   ^ row.toArray() }   proceed(guess) { int cows := 0; int bulls := 0;   if (guess.Length != 4) { bulls := -1 } else { try { for (int i := 0, i < 4, i+=1) { var ch := guess[i]; var number := ch.toString().toInt();   // check range ifnot (number > 0 && number < 10) { InvalidArgumentException.raise() };   // check duplicates var duplicate := guess.seekEach:(x => (x == ch)&&(x.equalReference(ch).Inverted)); if (nil != duplicate) { InvalidArgumentException.raise() };   if (number == theNumbers[i]) { bulls += 1 } else { if (theNumbers.ifExists(number)) { cows += 1 } } } } catch(Exception e) { bulls := -1 } };   bulls => -1 { console.printLine:"Not a valid guess."; ^ true } 4 { console.printLine:"Congratulations! You have won!"; ^ false }  : { theAttempt.append(1);   console.printLine("Your Score is ",bulls," bulls and ",cows," cows");   ^ true } } }   public program() { var gameMaster := new GameMaster();   (lazy:gameMaster.proceed(gameMaster.ask())).doWhile();   console.readChar() }
http://rosettacode.org/wiki/Caesar_cipher
Caesar cipher
Task Implement a Caesar cipher, both encoding and decoding. The key is an integer from 1 to 25. This cipher rotates (either towards left or right) the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "mono-alphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys. Caesar cipher is identical to Vigenère cipher with a key of length 1. Also, Rot-13 is identical to Caesar cipher with key 13. Related tasks Rot-13 Substitution Cipher Vigenère Cipher/Cryptanalysis
#Common_Lisp
Common Lisp
(defun encipher-char (ch key) (let* ((c (char-code ch)) (la (char-code #\a)) (ua (char-code #\A)) (base (cond ((<= la c (char-code #\z)) la) ((<= ua c (char-code #\Z)) ua) (nil)))) (if base (code-char (+ (mod (+ (- c base) key) 26) base)) ch)))   (defun caesar-cipher (str key) (map 'string #'(lambda (c) (encipher-char c key)) str))   (defun caesar-decipher (str key) (caesar-cipher str (- key)))   (let* ((original-text "The five boxing wizards jump quickly") (key 3) (cipher-text (caesar-cipher original-text key)) (recovered-text (caesar-decipher cipher-text key))) (format t " Original: ~a ~%" original-text) (format t "Encrypted: ~a ~%" cipher-text) (format t "Decrypted: ~a ~%" recovered-text))
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Phixmonti
Phixmonti
0 var e0 2 var e 0 var n 1 var fact 1e-15 var v   def printOp swap print print nl enddef   def test e e0 - abs v >= enddef   test while e var e0 n 1 + var n 2 n * 2 n * 1 + * fact * var fact 2 n * 2 + fact / e + var e test endwhile   2.718281828459045 var rE   "Computed e = " e tostr printOp "Real e = " rE tostr printOp "Error = " rE e - printOp "Number of iterations = " n printOp
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#PicoLisp
PicoLisp
(scl 15) (let (F 1 E 2.0 E0 0 N 2) (while (> E E0) (setq E0 E F (* F N)) (inc 'E (*/ 1.0 F)) (inc 'N) ) (prinl "e = " (format E *Scl)) )
http://rosettacode.org/wiki/Bulls_and_cows/Player
Bulls and cows/Player
Task Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts. One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list. Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring. Related tasks   Bulls and cows   Guess the number   Guess the number/With Feedback (Player)
#Ring
Ring
  # Project : Bulls and cows/Player   secret = "" while len(secret) != 4 c = char(48 + random(9)) if substr(secret, c) = 0 secret = secret + c ok end see "secret = " + secret + nl   possible = "" for i = 1234 to 9876 possible = possible + string(i) next   see "guess a four-digit number with no digit used twice." + nl guesses = 0 while true bulls = 0 cows = 0 if len(possible) = 4 guess = possible else guess = substr(possible, 4*random(len(possible) / 4) - 3, 4) ok see "computer guesses " + guess + nl guesses = guesses + 1 if guess = secret see "correctly guessed after " + guesses + " guesses!" + nl exit ok if len(guess) = 4 count(secret, guess, bulls, cows) ok i = 1 testbulls = 0 testcows = 0 while i <= len(possible) temp = substr(possible, i, 4) if len(guess) = 4 count(temp, guess, testbulls, testcows) ok if bulls=testbulls if cows=testcows i = i + 4 ok else possible = left(possible, i-1) + substr(possible, i+4) ok end if substr(possible, secret) = 0 exit ok end   func count(secret, guess, bulls, cows) bulls = 0 cows = 0 for nr = 1 to 4 c = secret[nr] if guess != 0 if guess[nr] = c bulls = bulls + 1 if substr(guess, c) > 0 cows = cows + 1 ok ok ok next see "giving " + bulls + " bull(s) and " + cows + " cow(s)." + nl return [bulls, cows]  
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers
Calendar - for "REAL" programmers
Task Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented   entirely without lowercase. Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide. (Hint: manually convert the code from the Calendar task to all UPPERCASE) This task also is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." Moreover this task is further inspired by the long lost corollary article titled: "Real programmers think in UPPERCASE"! Note: Whereas today we only need to worry about ASCII, UTF-8, UTF-16, UTF-32, UTF-7 and UTF-EBCDIC encodings, in the 1960s having code in UPPERCASE was often mandatory as characters were often stuffed into 36-bit words as 6 lots of 6-bit characters. More extreme words sizes include 60-bit words of the CDC 6000 series computers. The Soviets even had a national character set that was inclusive of all 4-bit, 5-bit, 6-bit & 7-bit depending on how the file was opened... And one rogue Soviet university went further and built a 1.5-bit based computer. Of course... as us Boomers have turned into Geezers we have become HARD OF HEARING, and suffer from chronic Presbyopia, hence programming in UPPERCASE is less to do with computer architecture and more to do with practically. :-) For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. FYI: a nice ASCII art file of Snoopy can be found at textfiles.com. Save with a .txt extension. Trivia: The terms uppercase and lowercase date back to the early days of the mechanical printing press. Individual metal alloy casts of each needed letter, or punctuation symbol, were meticulously added to a press block, by hand, before rolling out copies of a page. These metal casts were stored and organized in wooden cases. The more often needed minuscule letters were placed closer to hand, in the lower cases of the work bench. The less often needed, capitalized, majuscule letters, ended up in the harder to reach upper cases.
#Vedit_macro_language
Vedit macro language
BS(BF) CFT(22) #3 = 6 // NUMBER OF MONTHS PER LINE #2 = 1969 // YEAR #1 = 1 // STARTING MONTH IC(' ', COUNT, #3*9) IT("[SNOOPY]") IN(2) IC(' ', COUNT, #3*9+1) NI(#2) IN REPEAT(12/#3) { REPEAT (#3) { BS(BF) CALL("DRAW_CALENDAR") RCB(10, 1, EOB_POS, COLSET, 1, 21) BQ(OK) #5 = CP RI(10) GP(#5) EOL IC(9) #1++ } EOF IN(2) } RETURN   :DRAW_CALENDAR: NUM_PUSH(4,20) #20 = RF BOF DC(ALL)   NI(#1, LEFT+NOCR) IT("/1/") NI(#2, LEFT+NOCR) RCB(#20, BOL_POS, EOL_POS, DELETE) #10 = JDATE(@(#20))   #4 = #2+(#1==12) NI(#1%12+1, LEFT+NOCR) IT("/1/") NI(#4, LEFT+NOCR) RCB(#20, BOL_POS, CP, DELETE) #11 = JDATE(@(#20)) - #10 #7 = (#10-1) % 7   IF (#1==1) { RS(#20," JANUARY ") } IF (#1==2) { RS(#20," FEBRUARY") } IF (#1==3) { RS(#20," MARCH ") } IF (#1==4) { RS(#20," APRIL ") } IF (#1==5) { RS(#20," MAY ") } IF (#1==6) { RS(#20," JUNE ") } IF (#1==7) { RS(#20," JULY ") } IF (#1==8) { RS(#20," AUGUST ") } IF (#1==9) { RS(#20,"SEPTEMBER") } IF (#1==10) { RS(#20," OCTOBER ") } IF (#1==11) { RS(#20," NOVEMBER") } IF (#1==12) { RS(#20," DECEMBER") }   IT(" ") RI(#20) IN IT(" MO TU WE TH FR SA SU") IN IT(" --------------------") IN IC(' ', COUNT, #7*3) FOR (#8 = 1; #8 <= #11; #8++) { NI(#8, COUNT, 3) #5 = (#8+#10+5) % 7 IF (#5 == 6) { IN } } IT(" ")   REG_EMPTY(#20) NUM_POP(4,20) RETURN
http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#Gambas
Gambas
Public Sub Main()   Hello Print CopyIt("Hello ", 6) Print CopyIt("Hello ", 3, "!!")   End '_____________________________________________________________________________________ Public Sub CopyIt(sString As String, siNo As Short, Optional sEnd As String) As String Dim siCount As Short Dim sNewString As String   For siCount = 1 To siNo sNewString &= sString Next   Return Trim(sNewString) & sEnd   End '_____________________________________________________________________________________ Public Sub Hello()   Print "Hello world!"   End
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#MAD
MAD
NORMAL MODE IS INTEGER DIMENSION C(15)   C(0) = 1 THROUGH CALC, FOR N=1, 1, N.GE.15 CALC C(N) = ((4*N-2)*C(N-1))/(N+1)   THROUGH SHOW, FOR N=0, 1, N.GE.15 SHOW PRINT FORMAT CFMT,N,C(N)   VECTOR VALUES CFMT=$2HC(,I2,4H) = ,I7*$ END OF PROGRAM
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#Python
Python
def getitem(s, depth=0): out = [""] while s: c = s[0] if depth and (c == ',' or c == '}'): return out,s if c == '{': x = getgroup(s[1:], depth+1) if x: out,s = [a+b for a in out for b in x[0]], x[1] continue if c == '\\' and len(s) > 1: s, c = s[1:], c + s[1]   out, s = [a+c for a in out], s[1:]   return out,s   def getgroup(s, depth): out, comma = [], False while s: g,s = getitem(s, depth) if not s: break out += g   if s[0] == '}': if comma: return out, s[1:] return ['{' + a + '}' for a in out], s[1:]   if s[0] == ',': comma,s = True, s[1:]   return None   # stolen cowbells from Raku example for s in '''~/{Downloads,Pictures}/*.{jpg,gif,png} It{{em,alic}iz,erat}e{d,}, please. {,{,gotta have{ ,\, again\, }}more }cowbell! {}} some }{,{\\\\{ edge, edge} \,}{ cases, {here} \\\\\\\\\}'''.split('\n'): print "\n\t".join([s] + getitem(s)[0]) + "\n"
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#jq
jq
# Output: a stream of digits, least significant digit first def to_base($base): def butlast(s): label $out | foreach (s,null) as $x ({}; if $x == null then break $out else .emit = .prev | .prev = $x end; select(.emit).emit);   if . == 0 then 0 else butlast(recurse( if . == 0 then empty else ./$base | floor end ) % $base) end ;     def sameDigits($n; $b): ($n % $b) as $f | all( ($n | to_base($b)); . == $f)  ;   def isBrazilian: . as $n | if . < 7 then false elif (.%2 == 0 and . >= 8) then true else any(range(2; $n-1); sameDigits($n; .) ) end;   def brazilian_numbers($m; $n; $step): range($m; $n; $step) | select(isBrazilian);   def task($n): "First \($n) Brazilian numbers:", limit($n; brazilian_numbers(7; infinite; 1)), "First \($n) odd Brazilian numbers:", limit($n; brazilian_numbers(7; infinite; 2)), "First \($n) prime Brazilian numbers:", limit($n; brazilian_numbers(7; infinite; 2) | select(is_prime)) ;   task(20)    
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#Huginn
Huginn
import DateTime as dt; import Algorithms as algo; import Text as text;   class Calendar { _monthNames_ = none; _dayNames_ = none; constructor() { t = dt.now(); _monthNames_ = algo.materialize( algo.map( algo.range( 1, 13 ), @[t]( m ) { dt.format( "%B", t.set_date( 1, m, 1 ) ); } ), tuple ); _dayNames_ = algo.materialize( algo.map( algo.range( 1, 8 ), @[t]( d ) { dt.format( "%a", t.set_date( 1, 1, d ) )[:2]; } ), tuple ); } print_year( year_, cols_ ) { t = dt.now(); print( "{:^66d}\n".format( year_ ) ); for ( rm : algo.range( 12 / cols_ ) ) { m = rm * cols_; print( text.repeat( "{:^22s}", cols_ ).format( _monthNames_[m:m + cols_]... ) + "\n" ); day = []; daysInMonth = []; for ( mc : algo.range( cols_ ) ) { print( " {} {} {} {} {} {} {} ".format( _dayNames_... ) ); t.set_date( year_, m + mc + 1, 1 ); day.push( - t.get_day_of_week() + 1 ); daysInMonth.push( t.get_days_in_month() ); } print( "\n" ); haveDay = true; while ( haveDay ) { haveDay = false; for ( mc : algo.range( cols_ ) ) { for ( d : algo.range( 7 ) ) { if ( ( day[mc] > 0 ) && ( day[mc] <= daysInMonth[mc] ) ) { print( " {:2d}".format( day[mc] ) ); haveDay = true; } else { print( " " ); } day[mc] += 1; } print( " " ); } print( "\n" ); } } } }   main( argv_ ) { cal = Calendar(); cols = size( argv_ ) > 2 ? integer( argv_[2] ) : 3; if ( 12 % cols != 0 ) { cols = 3; } cal.print_year( size( argv_ ) > 1  ? integer( argv_[1] )  : dt.now().get_year(), cols ); }
http://rosettacode.org/wiki/Brownian_tree
Brownian tree
Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a   Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere within the field. Where is not particularly important; it could be randomized, or it could be a fixed point. Particles are injected into the field, and are individually given a (typically random) motion pattern. When a particle collides with the seed or tree, its position is fixed, and it's considered to be part of the tree. Because of the lax rules governing the random nature of the particle's placement and motion, no two resulting trees are really expected to be the same, or even necessarily have the same general shape.
#Locomotive_Basic
Locomotive Basic
10 MODE 1:DEFINT a-z:RANDOMIZE TIME:np=10000 20 INK 0,0:INK 1,26:BORDER 0 30 PLOT 320,200 40 FOR i=1 TO np 50 GOSUB 1000 60 IF TEST(x+1,y+1)+TEST(x,y+1)+TEST(x+1,y)+TEST(x-1,y-1)+TEST(x-1,y)+TEST(x,y-1)<>0 THEN 100 70 x=x+RND*2-1: y=y+RND*2-1 80 IF x<1 OR x>640 OR y<1 OR y>400 THEN GOSUB 1000 90 GOTO 60 100 PLOT x,y 110 NEXT 120 END 1000 ' Calculate new position 1010 x=RND*640 1020 y=RND*400 1030 RETURN
http://rosettacode.org/wiki/Bulls_and_cows
Bulls and cows
Bulls and Cows Task Create a four digit random number from the digits   1   to   9,   without duplication. The program should:   ask for guesses to this number   reject guesses that are malformed   print the score for the guess The score is computed as: The player wins if the guess is the same as the randomly chosen number, and the program ends. A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number. A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position. Related tasks   Bulls and cows/Player   Guess the number   Guess the number/With Feedback   Mastermind
#Elixir
Elixir
defmodule Bulls_and_cows do def play(size \\ 4) do secret = Enum.take_random(1..9, size) |> Enum.map(&to_string/1) play(size, secret) end   defp play(size, secret) do guess = input(size) if guess == secret do IO.puts "You win!" else {bulls, cows} = count(guess, secret) IO.puts " Bulls: #{bulls}; Cows: #{cows}" play(size, secret) end end   defp input(size) do guess = IO.gets("Enter your #{size}-digit guess: ") |> String.strip cond do guess == "" -> IO.puts "Give up" exit(:normal) String.length(guess)==size and String.match?(guess, ~r/^[1-9]+$/) -> String.codepoints(guess) true -> input(size) end end   defp count(guess, secret) do Enum.zip(guess, secret) |> Enum.reduce({0,0}, fn {g,s},{bulls,cows} -> cond do g == s -> {bulls + 1, cows} g in secret -> {bulls, cows + 1} true -> {bulls, cows} end end) end end   Bulls_and_cows.play
http://rosettacode.org/wiki/Caesar_cipher
Caesar cipher
Task Implement a Caesar cipher, both encoding and decoding. The key is an integer from 1 to 25. This cipher rotates (either towards left or right) the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "mono-alphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys. Caesar cipher is identical to Vigenère cipher with a key of length 1. Also, Rot-13 is identical to Caesar cipher with key 13. Related tasks Rot-13 Substitution Cipher Vigenère Cipher/Cryptanalysis
#Crystal
Crystal
class String ALPHABET = ("A".."Z").to_a   def caesar_cipher(num) self.tr(ALPHABET.join, ALPHABET.rotate(num).join) end end   # demo encrypted = "THEQUICKBROWNFOXJUMPSOVERTHELAZYDOG".caesar_cipher(5) decrypted = encrypted.caesar_cipher(-5)  
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#PowerShell
PowerShell
$e0 = 0 $e = 2 $n = 0 $fact = 1 while([Math]::abs($e-$e0) -gt 1E-15){ $e0 = $e $n += 1 $fact *= 2*$n*(2*$n+1) $e += (2*$n+2)/$fact }   Write-Host "Computed e = $e" Write-Host " Real e = $([Math]::Exp(1))" Write-Host " Error = $([Math]::Exp(1) - $e)" Write-Host "Number of iterations = $n"
http://rosettacode.org/wiki/Bulls_and_cows/Player
Bulls and cows/Player
Task Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts. One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list. Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring. Related tasks   Bulls and cows   Guess the number   Guess the number/With Feedback (Player)
#Ruby
Ruby
size = 4 scores = [] guesses = [] puts "Playing Bulls & Cows with #{size} unique digits." possible_guesses = [*'1'..'9'].permutation(size).to_a.shuffle   loop do guesses << current_guess = possible_guesses.pop print "Guess #{guesses.size} is #{current_guess.join}. Answer (bulls,cows)? " scores << score = gets.split(',').map(&:to_i)   # handle win break (puts "Yeah!") if score == [size,0]   # filter possible guesses possible_guesses.select! do |guess| bulls = guess.zip(current_guess).count{|g,cg| g == cg} cows = size - (guess - current_guess).size - bulls [bulls, cows] == score end   # handle 'no possible guesses left' if possible_guesses.empty? puts "Error in scoring?" guesses.zip(scores).each{|g, (b, c)| puts "#{g.join} => bulls #{b} cows #{c}"} break end end
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers
Calendar - for "REAL" programmers
Task Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented   entirely without lowercase. Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide. (Hint: manually convert the code from the Calendar task to all UPPERCASE) This task also is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." Moreover this task is further inspired by the long lost corollary article titled: "Real programmers think in UPPERCASE"! Note: Whereas today we only need to worry about ASCII, UTF-8, UTF-16, UTF-32, UTF-7 and UTF-EBCDIC encodings, in the 1960s having code in UPPERCASE was often mandatory as characters were often stuffed into 36-bit words as 6 lots of 6-bit characters. More extreme words sizes include 60-bit words of the CDC 6000 series computers. The Soviets even had a national character set that was inclusive of all 4-bit, 5-bit, 6-bit & 7-bit depending on how the file was opened... And one rogue Soviet university went further and built a 1.5-bit based computer. Of course... as us Boomers have turned into Geezers we have become HARD OF HEARING, and suffer from chronic Presbyopia, hence programming in UPPERCASE is less to do with computer architecture and more to do with practically. :-) For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. FYI: a nice ASCII art file of Snoopy can be found at textfiles.com. Save with a .txt extension. Trivia: The terms uppercase and lowercase date back to the early days of the mechanical printing press. Individual metal alloy casts of each needed letter, or punctuation symbol, were meticulously added to a press block, by hand, before rolling out copies of a page. These metal casts were stored and organized in wooden cases. The more often needed minuscule letters were placed closer to hand, in the lower cases of the work bench. The less often needed, capitalized, majuscule letters, ended up in the harder to reach upper cases.
#Visual_Basic_.NET
Visual Basic .NET
OPTION COMPARE BINARY OPTION EXPLICIT ON OPTION INFER ON OPTION STRICT ON   IMPORTS SYSTEM.GLOBALIZATION IMPORTS SYSTEM.TEXT IMPORTS SYSTEM.RUNTIME.INTEROPSERVICES IMPORTS SYSTEM.RUNTIME.COMPILERSERVICES   MODULE ARGHELPER READONLY _ARGDICT AS NEW DICTIONARY(OF STRING, STRING)()   DELEGATE FUNCTION TRYPARSE(OF T, TRESULT)(VALUE AS T, <OUT> BYREF RESULT AS TRESULT) AS BOOLEAN   SUB INITIALIZEARGUMENTS(ARGS AS STRING()) FOR EACH ITEM IN ARGS ITEM = ITEM.TOUPPERINVARIANT()   IF ITEM.LENGTH > 0 ANDALSO ITEM(0) <> """"C THEN DIM COLONPOS = ITEM.INDEXOF(":"C, STRINGCOMPARISON.ORDINAL)   IF COLONPOS <> -1 THEN ' SPLIT ARGUMENTS WITH COLUMNS INTO KEY(PART BEFORE COLON) / VALUE(PART AFTER COLON) PAIRS. _ARGDICT.ADD(ITEM.SUBSTRING(0, COLONPOS), ITEM.SUBSTRING(COLONPOS + 1, ITEM.LENGTH - COLONPOS - 1)) END IF END IF NEXT END SUB   SUB FROMARGUMENT(OF T)( KEY AS STRING, <OUT> BYREF VAR AS T, GETDEFAULT AS FUNC(OF T), TRYPARSE AS TRYPARSE(OF STRING, T), OPTIONAL VALIDATE AS PREDICATE(OF T) = NOTHING)   DIM VALUE AS STRING = NOTHING IF _ARGDICT.TRYGETVALUE(KEY.TOUPPERINVARIANT(), VALUE) THEN IF NOT (TRYPARSE(VALUE, VAR) ANDALSO (VALIDATE IS NOTHING ORELSE VALIDATE(VAR))) THEN CONSOLE.WRITELINE($"INVALID VALUE FOR {KEY}: {VALUE}") ENVIRONMENT.EXIT(-1) END IF ELSE VAR = GETDEFAULT() END IF END SUB END MODULE   MODULE PROGRAM SUB MAIN(ARGS AS STRING()) DIM DT AS DATE DIM COLUMNS, ROWS, MONTHSPERROW AS INTEGER DIM VERTSTRETCH, HORIZSTRETCH, RESIZEWINDOW AS BOOLEAN   INITIALIZEARGUMENTS(ARGS) FROMARGUMENT("DATE", DT, FUNCTION() NEW DATE(1969, 1, 1), ADDRESSOF DATE.TRYPARSE) FROMARGUMENT("COLS", COLUMNS, FUNCTION() 80, ADDRESSOF INTEGER.TRYPARSE, FUNCTION(V) V >= 20) FROMARGUMENT("ROWS", ROWS, FUNCTION() 43, ADDRESSOF INTEGER.TRYPARSE, FUNCTION(V) V >= 0) FROMARGUMENT("MS/ROW", MONTHSPERROW, FUNCTION() 0, ADDRESSOF INTEGER.TRYPARSE, FUNCTION(V) V <= 12 ANDALSO V <= COLUMNS \ 20) FROMARGUMENT("VSTRETCH", VERTSTRETCH, FUNCTION() TRUE, ADDRESSOF BOOLEAN.TRYPARSE) FROMARGUMENT("HSTRETCH", HORIZSTRETCH, FUNCTION() TRUE, ADDRESSOF BOOLEAN.TRYPARSE) FROMARGUMENT("WSIZE", RESIZEWINDOW, FUNCTION() TRUE, ADDRESSOF BOOLEAN.TRYPARSE)   ' THE SCROLL BAR IN COMMAND PROMPT SEEMS TO TAKE UP PART OF THE LAST COLUMN. IF RESIZEWINDOW THEN CONSOLE.WINDOWWIDTH = COLUMNS + 1 CONSOLE.WINDOWHEIGHT = ROWS END IF   IF MONTHSPERROW < 1 THEN MONTHSPERROW = MATH.MAX(COLUMNS \ 22, 1)   FOR EACH ROW IN GETCALENDARROWS(DT:=DT, WIDTH:=COLUMNS, HEIGHT:=ROWS, MONTHSPERROW:=MONTHSPERROW, VERTSTRETCH:=VERTSTRETCH, HORIZSTRETCH:=HORIZSTRETCH) CONSOLE.WRITE(ROW) NEXT END SUB   ITERATOR FUNCTION GETCALENDARROWS( DT AS DATE, WIDTH AS INTEGER, HEIGHT AS INTEGER, MONTHSPERROW AS INTEGER, VERTSTRETCH AS BOOLEAN, HORIZSTRETCH AS BOOLEAN) AS IENUMERABLE(OF STRING)   DIM YEAR = DT.YEAR DIM CALENDARROWCOUNT AS INTEGER = CINT(MATH.CEILING(12 / MONTHSPERROW)) ' MAKE ROOM FOR THE THREE EMPTY LINES ON TOP. DIM MONTHGRIDHEIGHT AS INTEGER = HEIGHT - 3   YIELD "[SNOOPY]".PADCENTER(WIDTH) & ENVIRONMENT.NEWLINE YIELD YEAR.TOSTRING(CULTUREINFO.INVARIANTCULTURE).PADCENTER(WIDTH) & ENVIRONMENT.NEWLINE YIELD ENVIRONMENT.NEWLINE   DIM MONTH = 0 DO WHILE MONTH < 12 DIM ROWHIGHESTMONTH = MATH.MIN(MONTH + MONTHSPERROW, 12)   DIM CELLWIDTH = WIDTH \ MONTHSPERROW DIM CELLCONTENTWIDTH = IF(MONTHSPERROW = 1, CELLWIDTH, (CELLWIDTH * 19) \ 20)   DIM CELLHEIGHT = MONTHGRIDHEIGHT \ CALENDARROWCOUNT DIM CELLCONTENTHEIGHT = (CELLHEIGHT * 19) \ 20   ' CREATES A MONTH CELL FOR THE SPECIFIED MONTH (1-12). DIM GETMONTHFROM = FUNCTION(M AS INTEGER) BUILDMONTH( DT:=NEW DATE(DT.YEAR, M, 1), WIDTH:=CELLCONTENTWIDTH, HEIGHT:=CELLCONTENTHEIGHT, VERTSTRETCH:=VERTSTRETCH, HORIZSTRETCH:=HORIZSTRETCH).SELECT(FUNCTION(X) X.PADCENTER(CELLWIDTH))   ' THE MONTHS IN THIS ROW OF THE CALENDAR. DIM MONTHSTHISROW AS IENUMERABLE(OF IENUMERABLE(OF STRING)) = ENUMERABLE.SELECT(ENUMERABLE.RANGE(MONTH + 1, ROWHIGHESTMONTH - MONTH), GETMONTHFROM)   DIM CALENDARROW AS IENUMERABLE(OF STRING) = INTERLEAVED( MONTHSTHISROW, USEINNERSEPARATOR:=FALSE, USEOUTERSEPARATOR:=TRUE, OUTERSEPARATOR:=ENVIRONMENT.NEWLINE)   DIM EN = CALENDARROW.GETENUMERATOR() DIM HASNEXT = EN.MOVENEXT() DO WHILE HASNEXT   DIM CURRENT AS STRING = EN.CURRENT   ' TO MAINTAIN THE (NOT STRICTLY NEEDED) CONTRACT OF YIELDING COMPLETE ROWS, KEEP THE NEWLINE AFTER ' THE CALENDAR ROW WITH THE LAST TERMINAL ROW OF THE ROW. HASNEXT = EN.MOVENEXT() YIELD IF(HASNEXT, CURRENT, CURRENT & ENVIRONMENT.NEWLINE) LOOP   MONTH += MONTHSPERROW LOOP END FUNCTION   ''' <SUMMARY> ''' INTERLEAVES THE ELEMENTS OF THE SPECIFIED SUB-SOURCES BY MAKING SUCCESSIVE PASSES THROUGH THE SOURCE ''' ENUMERABLE, YIELDING A SINGLE ELEMENT FROM EACH SUB-SOURCE IN SEQUENCE IN EACH PASS, OPTIONALLY INSERTING A ''' SEPARATOR BETWEEN ELEMENTS OF ADJACENT SUB-SOURCES AND OPTIONALLY A DIFFERENT SEPARATOR AT THE END OF EACH ''' PASS THROUGH ALL THE SOURCES. (I.E., BETWEEN ELEMENTS OF THE LAST AND FIRST SOURCE) ''' </SUMMARY> ''' <TYPEPARAM NAME="T">THE TYPE OF THE ELEMENTS OF THE SUB-SOURCES.</TYPEPARAM> ''' <PARAM NAME="SOURCES">A SEQUENCE OF THE SEQUENCES WHOSE ELEMENTS ARE TO BE INTERLEAVED.</PARAM> ''' <PARAM NAME="USEINNERSEPARATOR">WHETHER TO INSERT <PARAMREF NAME="USEINNERSEPARATOR"/> BETWEEN THE ELEMENTS OFADJACENT SUB-SOURCES.</PARAM> ''' <PARAM NAME="INNERSEPARATOR">THE SEPARATOR BETWEEN ELEMENTS OF ADJACENT SUB-SOURCES.</PARAM> ''' <PARAM NAME="USEOUTERSEPARATOR">WHETHER TO INSERT <PARAMREF NAME="OUTERSEPARATOR"/> BETWEEN THE ELEMENTS OF THE LAST AND FIRST SUB-SOURCES.</PARAM> ''' <PARAM NAME="OUTERSEPARATOR">THE SEPARATOR BETWEEN ELEMENTS OF THE LAST AND FIRST SUB-SOURCE.</PARAM> ''' <PARAM NAME="WHILEANY">IF <SEE LANGWORD="TRUE"/>, THE ENUMERATION CONTINUES UNTIL EVERY GIVEN SUBSOURCE IS EMPTY; ''' IF <SEE LANGWORD="FALSE"/>, THE ENUMERATION STOPS AS SOON AS ANY ENUMERABLE NO LONGER HAS AN ELEMENT TO SUPPLY FOR THE NEXT PASS.</PARAM> ITERATOR FUNCTION INTERLEAVED(OF T)( SOURCES AS IENUMERABLE(OF IENUMERABLE(OF T)), OPTIONAL USEINNERSEPARATOR AS BOOLEAN = FALSE, OPTIONAL INNERSEPARATOR AS T = NOTHING, OPTIONAL USEOUTERSEPARATOR AS BOOLEAN = FALSE, OPTIONAL OUTERSEPARATOR AS T = NOTHING, OPTIONAL WHILEANY AS BOOLEAN = TRUE) AS IENUMERABLE(OF T) DIM SOURCEENUMERATORS AS IENUMERATOR(OF T)() = NOTHING   TRY SOURCEENUMERATORS = SOURCES.SELECT(FUNCTION(X) X.GETENUMERATOR()).TOARRAY() DIM NUMSOURCES = SOURCEENUMERATORS.LENGTH DIM ENUMERATORSTATES(NUMSOURCES - 1) AS BOOLEAN   DIM ANYPREVITERS AS BOOLEAN = FALSE DO ' INDICES OF FIRST AND LAST SUB-SOURCES THAT HAVE ELEMENTS. DIM FIRSTACTIVE = -1, LASTACTIVE = -1   ' DETERMINE WHETHER EACH SUB-SOURCE THAT STILL HAVE ELEMENTS. FOR I = 0 TO NUMSOURCES - 1 ENUMERATORSTATES(I) = SOURCEENUMERATORS(I).MOVENEXT() IF ENUMERATORSTATES(I) THEN IF FIRSTACTIVE = -1 THEN FIRSTACTIVE = I LASTACTIVE = I END IF NEXT   ' DETERMINE WHETHER TO YIELD ANYTHING IN THIS ITERATION BASED ON WHETHER WHILEANY IS TRUE. ' NOT YIELDING ANYTHING THIS ITERATION IMPLIES THAT THE ENUMERATION HAS ENDED. DIM THISITERHASRESULTS AS BOOLEAN = IF(WHILEANY, FIRSTACTIVE <> -1, FIRSTACTIVE = 0 ANDALSO LASTACTIVE = NUMSOURCES - 1) IF NOT THISITERHASRESULTS THEN EXIT DO   ' DON'T INSERT A SEPARATOR ON THE FIRST PASS. IF ANYPREVITERS THEN IF USEOUTERSEPARATOR THEN YIELD OUTERSEPARATOR ELSE ANYPREVITERS = TRUE END IF   ' GO THROUGH AND YIELD FROM THE SUB-SOURCES THAT STILL HAVE ELEMENTS. FOR I = 0 TO NUMSOURCES - 1 IF ENUMERATORSTATES(I) THEN ' DON'T INSERT A SEPARATOR BEFORE THE FIRST ELEMENT. IF I > FIRSTACTIVE ANDALSO USEINNERSEPARATOR THEN YIELD INNERSEPARATOR YIELD SOURCEENUMERATORS(I).CURRENT END IF NEXT LOOP   FINALLY IF SOURCEENUMERATORS ISNOT NOTHING THEN FOR EACH EN IN SOURCEENUMERATORS EN.DISPOSE() NEXT END IF END TRY END FUNCTION   ''' <SUMMARY> ''' RETURNS THE ROWS REPRESENTING ONE MONTH CELL WITHOUT TRAILING NEWLINES. APPROPRIATE LEADING AND TRAILING ''' WHITESPACE IS ADDED SO THAT EVERY ROW HAS THE LENGTH OF WIDTH. ''' </SUMMARY> ''' <PARAM NAME="DT">A DATE WITHIN THE MONTH TO REPRESENT.</PARAM> ''' <PARAM NAME="WIDTH">THE WIDTH OF THE CELL.</PARAM> ''' <PARAM NAME="HEIGHT">THE HEIGHT.</PARAM> ''' <PARAM NAME="VERTSTRETCH">IF <SEE LANGWORD="TRUE" />, BLANK ROWS ARE INSERTED TO FIT THE AVAILABLE HEIGHT. ''' OTHERWISE, THE CELL HAS A CONSTANT HEIGHT OF </PARAM> ''' <PARAM NAME="HORIZSTRETCH">IF <SEE LANGWORD="TRUE" />, THE SPACING BETWEEN INDIVIDUAL DAYS IS INCREASED TO ''' FIT THE AVAILABLE WIDTH. OTHERWISE, THE CELL HAS A CONSTANT WIDTH OF 20 CHARACTERS AND IS PADDED TO BE IN ''' THE CENTER OF THE EXPECTED WIDTH.</PARAM> ITERATOR FUNCTION BUILDMONTH(DT AS DATE, WIDTH AS INTEGER, HEIGHT AS INTEGER, VERTSTRETCH AS BOOLEAN, HORIZSTRETCH AS BOOLEAN) AS IENUMERABLE(OF STRING) CONST DAY_WDT = 2 ' WIDTH OF A DAY. CONST ALLDAYS_WDT = DAY_WDT * 7 ' WIDTH OF AL LDAYS COMBINED.   ' NORMALIZE THE DATE TO JANUARY 1. DT = NEW DATE(DT.YEAR, DT.MONTH, 1)   ' HORIZONTAL WHITESPACE BETWEEN DAYS OF THE WEEK. CONSTANT OF 6 REPRESENTS 6 SEPARATORS PER LINE. DIM DAYSEP AS NEW STRING(" "C, MATH.MIN((WIDTH - ALLDAYS_WDT) \ 6, IF(HORIZSTRETCH, INTEGER.MAXVALUE, 1))) ' NUMBER OF BLANK LINES BETWEEN ROWS. DIM VERTBLANKCOUNT = IF(NOT VERTSTRETCH, 0, (HEIGHT - 8) \ 7)   ' WIDTH OF EACH DAY * 7 DAYS IN ONE ROW + DAY SEPARATOR LENGTH * 6 SEPARATORS PER LINE. DIM BLOCKWIDTH = ALLDAYS_WDT + DAYSEP.LENGTH * 6   ' THE WHITESPACE AT THE BEGINNING OF EACH LINE. DIM LEFTPAD AS NEW STRING(" "C, (WIDTH - BLOCKWIDTH) \ 2) ' THE WHITESPACE FOR BLANK LINES. DIM FULLPAD AS NEW STRING(" "C, WIDTH)   ' LINES ARE "STAGED" IN THE STRINGBUILDER. DIM SB AS NEW STRINGBUILDER(LEFTPAD) DIM NUMLINES = 0   ' GET THE CURRENT LINE SO FAR FORM THE STRINGBUILDER AND BEGIN A NEW LINE. ' RETURNS THE CURRENT LINE AND TRAILING BLANK LINES USED FOR VERTICAL PADDING (IF ANY). ' RETURNS EMPTY ENUMERABLE IF THE HEIGHT REQUIREMENT HAS BEEN REACHED. DIM ENDLINE = FUNCTION() AS IENUMERABLE(OF STRING) DIM FINISHEDLINE AS STRING = SB.TOSTRING().PADRIGHT(WIDTH) SB.CLEAR() SB.APPEND(LEFTPAD)   ' USE AN INNER ITERATOR TO PREVENT LAZY EXECUTION OF SIDE EFFECTS OF OUTER FUNCTION. RETURN IF(NUMLINES >= HEIGHT, ENUMERABLE.EMPTY(OF STRING)(), ITERATOR FUNCTION() AS IENUMERABLE(OF STRING) YIELD FINISHEDLINE NUMLINES += 1   FOR I = 1 TO VERTBLANKCOUNT IF NUMLINES >= HEIGHT THEN RETURN YIELD FULLPAD NUMLINES += 1 NEXT END FUNCTION()) END FUNCTION   ' YIELD THE MONTH NAME. SB.APPEND(PADCENTER(DT.TOSTRING("MMMM", CULTUREINFO.INVARIANTCULTURE), BLOCKWIDTH).TOUPPER()) FOR EACH L IN ENDLINE() YIELD L NEXT   ' YIELD THE HEADER OF WEEKDAY NAMES. DIM WEEKNMABBREVS = [ENUM].GETNAMES(GETTYPE(DAYOFWEEK)).SELECT(FUNCTION(X) X.SUBSTRING(0, 2).TOUPPER()) SB.APPEND(STRING.JOIN(DAYSEP, WEEKNMABBREVS)) FOR EACH L IN ENDLINE() YIELD L NEXT   ' DAY OF WEEK OF FIRST DAY OF MONTH. DIM STARTWKDY = CINT(DT.DAYOFWEEK)   ' INITIALIZE WITH EMPTY SPACE FOR THE FIRST LINE. DIM FIRSTPAD AS NEW STRING(" "C, (DAY_WDT + DAYSEP.LENGTH) * STARTWKDY) SB.APPEND(FIRSTPAD)   DIM D = DT DO WHILE D.MONTH = DT.MONTH SB.APPENDFORMAT(CULTUREINFO.INVARIANTCULTURE, $"{{0,{DAY_WDT}}}", D.DAY)   ' EACH ROW ENDS ON SATURDAY. IF D.DAYOFWEEK = DAYOFWEEK.SATURDAY THEN FOR EACH L IN ENDLINE() YIELD L NEXT ELSE SB.APPEND(DAYSEP) END IF   D = D.ADDDAYS(1) LOOP   ' KEEP ADDING EMPTY LINES UNTIL THE HEIGHT QUOTA IS MET. DIM NEXTLINES AS IENUMERABLE(OF STRING) DO NEXTLINES = ENDLINE() FOR EACH L IN NEXTLINES YIELD L NEXT LOOP WHILE NEXTLINES.ANY() END FUNCTION   ''' <SUMMARY> ''' RETURNS A NEW STRING THAT CENTER-ALIGNS THE CHARACTERS IN THIS STRING BY PADDING TO THE LEFT AND RIGHT WITH ''' THE SPECIFIED CHARACTER TO A SPECIFIED TOTAL LENGTH. ''' </SUMMARY> ''' <PARAM NAME="S">THE STRING TO CENTER-ALIGN.</PARAM> ''' <PARAM NAME="TOTALWIDTH">THE NUMBER OF CHARACTERS IN THE RESULTING STRING.</PARAM> ''' <PARAM NAME="PADDINGCHAR">THE PADDING CHARACTER.</PARAM> <EXTENSION()> PRIVATE FUNCTION PADCENTER(S AS STRING, TOTALWIDTH AS INTEGER, OPTIONAL PADDINGCHAR AS CHAR = " "C) AS STRING RETURN S.PADLEFT(((TOTALWIDTH - S.LENGTH) \ 2) + S.LENGTH, PADDINGCHAR).PADRIGHT(TOTALWIDTH, PADDINGCHAR) END FUNCTION END MODULE
http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#Go
Go
noArgs()
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#Maple
Maple
CatalanNumbers := proc( n::posint ) return seq( (2*i)!/((i + 1)!*i!), i = 0 .. n - 1 ); end proc: CatalanNumbers(15);  
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#Racket
Racket
#lang racket/base (require racket/match) (define (merge-lists as . bss) (match bss ['() as] [(cons b bt) (apply merge-lists (for*/list ((a (in-list as)) (b (in-list b))) (append a b)) bt)]))   (define (get-item cs depth) (let loop ((out '(())) (cs cs)) (match cs ['() (values out cs)] [`(,(or #\, #\}) . ,more) #:when (positive? depth) (values out cs)] [`(#\{ . ,more) (=> no-group-match) (define-values (group-out group-rem) (get-group more (add1 depth) no-group-match)) (loop (merge-lists out group-out) group-rem)] [(or `(#\\ ,c ,more ...) `(,c . ,more)) (loop (merge-lists out (list (list c))) more)])))   (define (get-group cs depth no-group-match) (let loop ((out '()) (cs cs) (comma? #f)) (when (null? cs) (no-group-match)) (define-values (item-out item-rem) (get-item cs depth)) (when (null? item-rem) (no-group-match)) (let ((out (append out item-out))) (match item-rem [`(#\} . ,more) #:when comma? (values out more)] [`(#\} . ,more) (values (merge-lists '((#\{)) out '((#\}))) more)] [`(#\, . ,more) (loop out more #t)] [_ (no-group-match)]))))   (define (brace-expand s) (let-values (([out rem] (get-item (string->list s) 0))) (map list->string out)))   (module+ test (define patterns (list "~/{Downloads,Pictures}/*.{jpg,gif,png}" "It{{em,alic}iz,erat}e{d,}, please." #<<P {,{,gotta have{ ,\, again\, }}more }cowbell! P #<<P {}} some }{,{\\\\{ edge, edge} \,}{ cases, {here} \\\\\\\\\} P )) (for ((s (in-list patterns)) #:when (printf "expand: ~a~%" s) (x (in-list (brace-expand s)))) (printf "\t~a~%" x)))
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#Raku
Raku
grammar BraceExpansion { token TOP { ( <meta> | . )* } token meta { '{' <alts> '}' | \\ . } token alts { <alt>+ % ',' } token alt { ( <meta> | <-[ , } ]> )* } }   sub crosswalk($/) { |[X~] flat '', $0.map: -> $/ { $<meta><alts><alt>.&alternatives or ~$/ } }   sub alternatives($_) { when :not { () } when 1 { '{' X~ $_».&crosswalk X~ '}' } default { $_».&crosswalk } }   sub brace-expand($s) { crosswalk BraceExpansion.parse($s) }   # Testing:   sub bxtest(*@s) { for @s -> $s { say "\n$s"; for brace-expand($s) { say " ", $_; } } }   bxtest Q:to/END/.lines; ~/{Downloads,Pictures}/*.{jpg,gif,png} It{{em,alic}iz,erat}e{d,}, please. {,{,gotta have{ ,\, again\, }}more }cowbell! a{b{1,2}c a{1,2}b}c a{1,{2},3}b more{ darn{ cowbell,},} ab{c,d\,e{f,g\h},i\,j{k,l\,m}n,o\,p}qr {a,{\,b}c a{b,{{c}} {a{\}b,c}d END
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#Julia
Julia
using Primes, Lazy   function samedigits(n, b) n, f = divrem(n, b) while n > 0 n, f2 = divrem(n, b) if f2 != f return false end end true end   isbrazilian(n) = n >= 7 && (iseven(n) || any(b -> samedigits(n, b), 2:n-2)) brazilians = filter(isbrazilian, Lazy.range()) oddbrazilians = filter(n -> isodd(n) && isbrazilian(n), Lazy.range()) primebrazilians = filter(n -> isprime(n) && isbrazilian(n), Lazy.range())   println("The first 20 Brazilian numbers are: ", take(20, brazilians))   println("The first 20 odd Brazilian numbers are: ", take(20, oddbrazilians))   println("The first 20 prime Brazilian numbers are: ", take(20, primebrazilians))  
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#Icon_and_Unicon
Icon and Unicon
procedure main(A) printCalendar(\A[1]|1969) end   procedure printCalendar(year) #: Print a 3 column x 80 char calendar cols := 3 # fixed width mons := [] # table of months "January February March April May June " || "July August September October November December " ? while put(mons, tab(find(" "))) do move(1)   write(center("[Snoopy Picture]",cols * 24 + 4)) # mandatory .. write(center(year,cols * 24 + 4), "\n") # ... headers   M := list(cols) # coexpr container every mon := 0 to 9 by cols do { # go through months by cols writes(" ") every i := 1 to cols do { writes(center(mons[mon+i],24)) # header months M[i] := create CalendarFormatWeek(year,mon + i) # formatting coexpr } write() every 1 to 7 do { # 1 to max rows every c := 1 to cols do { # for each column writes(" ") every 1 to 7 do writes(right(@M[c],3)) # each row day element } write() } } return end   link datetime   procedure CalendarFormatWeek(year,m) #: Format Week for Calendar static D initial D := [31,28,31,30,31,30,31,31,30,31,30,31]   every suspend "Su"|"Mo"|"Tu"|"We"|"Th"|"Fr"|"Sa" # header every 1 to (d := (julian(m,1,year)+1)%7) do suspend "" # lead day alignment every suspend 1 to D[m] do d +:= 1 # days if m = 2 & IsLeapYear(year) then suspend (d +:= 1, 29) # LY adjustment every d to (6*7) do suspend "" # trailer alignment end
http://rosettacode.org/wiki/Brownian_tree
Brownian tree
Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a   Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere within the field. Where is not particularly important; it could be randomized, or it could be a fixed point. Particles are injected into the field, and are individually given a (typically random) motion pattern. When a particle collides with the seed or tree, its position is fixed, and it's considered to be part of the tree. Because of the lax rules governing the random nature of the particle's placement and motion, no two resulting trees are really expected to be the same, or even necessarily have the same general shape.
#Lua
Lua
function SetSeed( f ) for i = 1, #f[1] do -- the whole boundary of the scene is used as the seed f[1][i] = 1 f[#f][i] = 1 end for i = 1, #f do f[i][1] = 1 f[i][#f[1]] = 1 end end   function SetParticle( f ) local pos_x, pos_y repeat pos_x = math.random( #f ) pos_y = math.random( #f[1] ) until f[pos_x][pos_y] == 0   return pos_x, pos_y end     function Iterate( f, num_particles ) for i = 1, num_particles do local pos_x, pos_y = SetParticle( f )   while true do local dx = math.random(5) - 3 local dy = math.random(5) - 3   if ( pos_x+dx >= 1 and pos_x+dx <= #f and pos_y+dy >= 1 and pos_y+dy <= #f[1] ) then if f[pos_x+dx][pos_y+dy] ~= 0 then f[pos_x][pos_y] = 1 break else pos_x = pos_x + dx pos_y = pos_y + dy end end end end end     size_x, size_y = 400, 400 -- size of the scene num_particles = 16000   math.randomseed( os.time() )   f = {} for i = 1, size_x do f[i] = {} for j = 1, size_y do f[i][j] = 0 end end   SetSeed( f ) Iterate( f, num_particles )   -- prepare the data for writing into a ppm-image file for i = 1, size_x do for j = 1, size_y do if f[i][j] == 1 then f[i][j] = 255 end end end Write_PPM( "brownian_tree.ppm", ConvertToColorImage(f) )
http://rosettacode.org/wiki/Bulls_and_cows
Bulls and cows
Bulls and Cows Task Create a four digit random number from the digits   1   to   9,   without duplication. The program should:   ask for guesses to this number   reject guesses that are malformed   print the score for the guess The score is computed as: The player wins if the guess is the same as the randomly chosen number, and the program ends. A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number. A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position. Related tasks   Bulls and cows/Player   Guess the number   Guess the number/With Feedback   Mastermind
#Erlang
Erlang
-module(bulls_and_cows). -export([generate_secret/0, score_guess/2, play/0]).   % generate the secret code generate_secret() -> generate_secret([], 4, lists:seq(1,9)). generate_secret(Secret, 0, _) -> Secret; generate_secret(Secret, N, Digits) -> Next = lists:nth(random:uniform(length(Digits)), Digits), generate_secret(Secret ++ [Next], N - 1, Digits -- [Next]).   % evaluate a guess score_guess(Secret, Guess) when length(Secret) =/= length(Guess) -> throw(badguess); score_guess(Secret, Guess) -> Bulls = count_bulls(Secret,Guess), Cows = count_cows(Secret, Guess, Bulls), [Bulls, Cows].   % count bulls (exact matches) count_bulls(Secret, Guess) -> length(lists:filter(fun(I) -> lists:nth(I,Secret) == lists:nth(I,Guess) end, lists:seq(1, length(Secret)))).   % count cows (digits present but out of place) count_cows(Secret, Guess, Bulls) -> length(lists:filter(fun(I) -> lists:member(I, Guess) end, Secret)) - Bulls.   % play a game play() -> play_round(generate_secret()).   play_round(Secret) -> play_round(Secret, read_guess()).   play_round(Secret, Guess) -> play_round(Secret, Guess, score_guess(Secret,Guess)).   play_round(_, _, [4,0]) -> io:put_chars("Correct!\n");   play_round(Secret, _, Score) -> io:put_chars("\tbulls:"), io:write(hd(Score)), io:put_chars(", cows:"), io:write(hd(tl(Score))), io:put_chars("\n"), play_round(Secret).   read_guess() -> lists:map(fun(D)->D-48 end, lists:sublist(io:get_line("Enter your 4-digit guess: "), 4)).
http://rosettacode.org/wiki/Caesar_cipher
Caesar cipher
Task Implement a Caesar cipher, both encoding and decoding. The key is an integer from 1 to 25. This cipher rotates (either towards left or right) the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "mono-alphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys. Caesar cipher is identical to Vigenère cipher with a key of length 1. Also, Rot-13 is identical to Caesar cipher with key 13. Related tasks Rot-13 Substitution Cipher Vigenère Cipher/Cryptanalysis
#Cubescript
Cubescript
alias modn [ mod (+ (mod $arg1 $arg2) $arg2) $arg2 ] //Cubescript's built-in mod will fail on negative numbers   alias cipher [ push alpha [ "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z" "a b c d e f g h i j k l m n o p q r s t u v w x y z" ] [ push chars [] [ loop i (strlen $arg1) [ looplist n $alpha [ if (! (listlen $chars)) [ alias chars (? (> (listindex $n (substr $arg1 $i 1)) -1) $n []) ] ] alias arg1 ( concatword (substr $arg1 0 $i) ( ? (> (listindex $chars (substr $arg1 $i 1)) -1) ( at $chars ( modn (+ ( listindex $chars (substr $arg1 $i 1) ) $arg2) (listlen $chars) ) ) (substr $arg1 $i 1) ) (substr $arg1 (+ $i 1) (strlen $arg1)) ) alias chars [] ] ] ] result $arg1 ]   alias decipher [ push alpha [ "A B C D E F G H I J K L M N O P Q R S T U V W X Y Z" "a b c d e f g h i j k l m n o p q r s t u v w x y z" ] [ push chars [] [ loop i (strlen $arg1) [ looplist n $alpha [ if (! (listlen $chars)) [ alias chars (? (> (listindex $n (substr $arg1 $i 1)) -1) $n []) ] ] alias arg1 ( concatword (substr $arg1 0 $i) ( ? (> (listindex $chars (substr $arg1 $i 1)) -1) ( at $chars ( modn (- ( listindex $chars (substr $arg1 $i 1) ) $arg2 ) (listlen $chars) ) ) (substr $arg1 $i 1) ) (substr $arg1 (+ $i 1) (strlen $arg1)) ) alias chars [] ] ] ] result $arg1 ]
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Processing
Processing
void setup() { double e = 0; long factorial = 1; for (int i = 0; i < 11; i++) { e += (double) (2 * i + 1) / factorial; factorial *= (2 * i + 1) * (2 * i + 2); } println("After 11 iterations"); println("Computed value: " + e); println("Real value: " + Math.E); println("Error: " + (e - Math.E)); }
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Prolog
Prolog
  % Calculate the value e = exp 1 % Use Newton's method: x0 = 2; y = x(2 - ln x)   tolerance(1e-15).   exp1_iter(L) :- lazy_list(newton, 2, L).   newton(X0, X1, X1) :- X1 is X0*(2 - log(X0)).   e([X1, X2|_], X1) :- tolerance(Eps), abs(X2 - X1) < Eps. e([_|Xs], E) :- e(Xs, E).   main :- exp1_iter(Iter), e(Iter, E), format("e = ~w~n", [E]), halt.   ?- main.  
http://rosettacode.org/wiki/Bulls_and_cows/Player
Bulls and cows/Player
Task Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts. One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list. Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring. Related tasks   Bulls and cows   Guess the number   Guess the number/With Feedback (Player)
#Scala
Scala
  def allCombinations: Seq[List[Byte]] = { (0 to 9).map(_.byteValue).toList.combinations(4).toList.flatMap(_.permutations) }   def nextGuess(possible: Seq[List[Byte]]): List[Byte] = possible match { case Nil => throw new IllegalStateException case List(only) => only case _ => possible(Random.nextInt(possible.size)) }   def doGuess(guess: List[Byte]): Pair[Int, Int] = { println("My guess is " + guess); val arr = readLine().split(' ').map(Integer.valueOf(_)) (arr(0), arr(1)) }   def testGuess(alt: List[Byte], guess: List[Byte]): Pair[Int, Int] = { val bulls =alt.zip(guess).filter(p => p._1 == p._2).size val cows = guess.filter(alt.contains(_)).size - bulls (bulls, cows) }   def play(possible: Seq[List[Byte]]): List[Byte] = { val curGuess = nextGuess(possible) val bc = doGuess(curGuess) if (bc._1 == 4) { println("Ye-haw!"); curGuess } else play(possible.filter(p => testGuess(p, curGuess) == bc))   }   def main(args: Array[String]) { play(allCombinations) }  
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers
Calendar - for "REAL" programmers
Task Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented   entirely without lowercase. Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide. (Hint: manually convert the code from the Calendar task to all UPPERCASE) This task also is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." Moreover this task is further inspired by the long lost corollary article titled: "Real programmers think in UPPERCASE"! Note: Whereas today we only need to worry about ASCII, UTF-8, UTF-16, UTF-32, UTF-7 and UTF-EBCDIC encodings, in the 1960s having code in UPPERCASE was often mandatory as characters were often stuffed into 36-bit words as 6 lots of 6-bit characters. More extreme words sizes include 60-bit words of the CDC 6000 series computers. The Soviets even had a national character set that was inclusive of all 4-bit, 5-bit, 6-bit & 7-bit depending on how the file was opened... And one rogue Soviet university went further and built a 1.5-bit based computer. Of course... as us Boomers have turned into Geezers we have become HARD OF HEARING, and suffer from chronic Presbyopia, hence programming in UPPERCASE is less to do with computer architecture and more to do with practically. :-) For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. FYI: a nice ASCII art file of Snoopy can be found at textfiles.com. Save with a .txt extension. Trivia: The terms uppercase and lowercase date back to the early days of the mechanical printing press. Individual metal alloy casts of each needed letter, or punctuation symbol, were meticulously added to a press block, by hand, before rolling out copies of a page. These metal casts were stored and organized in wooden cases. The more often needed minuscule letters were placed closer to hand, in the lower cases of the work bench. The less often needed, capitalized, majuscule letters, ended up in the harder to reach upper cases.
#Wren
Wren
IMPORT "/DATE" FOR DATE IMPORT "/FMT" FOR FMT IMPORT "/SEQ" FOR LST   VAR CALENDAR = FN.NEW { |YEAR| VAR SNOOPY = "🐶" VAR DAYS = "SU MO TU WE TH FR SA" VAR MONTHS = [ "JANUARY", "FEBRUARY", "MARCH", "APRIL", "MAY", "JUNE", "JULY", "AUGUST", "SEPTEMBER", "OCTOBER", "NOVEMBER", "DECEMBER" ] FMT.PRINT("$70M", SNOOPY) VAR YEARSTR = "--- %(YEAR) ---" FMT.PRINT("$70M\N", YEARSTR) VAR FIRST = LIST.FILLED(3, 0) VAR MLEN = LIST.FILLED(3, 0) VAR C = 0 FOR (CHUNK IN LST.CHUNKS(MONTHS, 3)) { FOR (I IN 0..2) FMT.WRITE("$20M ", CHUNK[I]) SYSTEM.PRINT() FOR (I IN 0..2) SYSTEM.WRITE("%(DAYS) ") SYSTEM.PRINT() FIRST[0] = DATE.NEW(YEAR, C*3 + 1, 1).DAYOFWEEK % 7 FIRST[1] = DATE.NEW(YEAR, C*3 + 2, 1).DAYOFWEEK % 7 FIRST[2] = DATE.NEW(YEAR, C*3 + 3, 1).DAYOFWEEK % 7 MLEN[0] = DATE.MONTHLENGTH(YEAR, C*3 + 1) MLEN[1] = DATE.MONTHLENGTH(YEAR, C*3 + 2) MLEN[2] = DATE.MONTHLENGTH(YEAR, C*3 + 3) FOR (I IN 0..5) { FOR (J IN 0..2) { VAR START = 1 + 7 * I - FIRST[J] FOR (K IN START..START+6) { IF (K >= 1 && K <= MLEN[J]) { FMT.WRITE("$2D ", K) } ELSE { SYSTEM.WRITE(" ") } } SYSTEM.WRITE(" ") } SYSTEM.PRINT() } SYSTEM.PRINT() C = C + 1 } }   CALENDAR.CALL(1969)
http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#Groovy
Groovy
noArgs()
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
CatalanN[n_Integer /; n >= 0] := (2 n)!/((n + 1)! n!)
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#REXX
REXX
/*- REXX -------------------------------------------------------------- * Brace expansion * 26.07.2016 * s.* holds the set of strings *--------------------------------------------------------------------*/ text.1='{,{,gotta have{ ,\, again\, }}more }cowbell!' text.2='~/{Downloads,Pictures}/*.{jpg,gif,png}' text.3='It{{em,alic}iz,erat}e{d,}, please. ' text.4='{}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} ' text.5='x{,a,b,c}{d,e}y' text.6='aa{,{,11}cc}22' text.7='{}' Parse Arg dbg oid='brace.xxx'; 'erase' oid Do case=1 To 7 Call brac text.case End Return brac: s.=0 Parse Arg s Say '' Say ' 's s.1.0=1 /* first iteration */ s.1.1=s /* the initial string */ Do it=1 To 10 Until todo=0 /* Iterate until all done */ todo=0 /* will be 1 if more to be done */ Call dbg 'Iteration' it do di=1 To s.it.0 /* show current state */ Call dbg 's.'it'.'di s.it.di End ita=it+1 /* index for next set of strings*/ xp=0 do di=1 To s.it.0 /* loop over all strings */ Call dbg it'.'di s.it.di Call bra s.it.di /* analyze current string */ If braces=1 Then Do /* If brace groups were found */ Do bgi=1 To bgdata.0 /* loop over grace groups */ If end.bgi=0 Then Iterate /* Incomplete bg (... ) */ clist='' Do cj=1 To ci.bgi.0 clist=clist ci.bgi.cj End Call dbg bgdata.bgi '->' clist If ccount.bgi>0 Then Do /* comma(s) founf in bg */ Call expand bgi /* expand this bg */ xp=1 /* indicate that we worked */ Leave End End If xp=0 Then Do /* nothing done */ z=s.ita.0+1 /* copy string to next iteration*/ s.ita.z=s.it.di End End Else Do /* no brace group */ z=s.ita.0+1 /* copy string to next iteration*/ s.ita.z=s s.ita.0=z End End Do dd=1 To s.ita.0 /* log current set of strings */ Call dbg ita dd s.ita.dd End End Do dd=1 To s.it.0 /* show final set of strings */ Say dd s.it.dd End Return   bra: /*--------------------------------------------------------------------- * Analyze the given string * Input: s * Output: * bgdata.* Array of data about brace groups: * level start column comma positions end column *--------------------------------------------------------------------*/ parse Arg s Call dbg 'bra:' s level=0 bgdata.=0 bgn=0 bgnmax=0 ccount.=0 ol='' ci.=0 bgnl='' braces=0 end.=0 escape=0 Do i=1 To length(s) c=substr(s,i,1) Select When escape Then escape=0 When c='\' Then escape=1 When c='{' Then Do level=level+1 Call bm c co=level End When c='}' Then Do If level>0 Then Do co=level Call bm c level=level-1 End End When c=',' Then Do co=level If co>0 Then Do ccount.bgn=ccount.bgn+1 z=ccount.bgn ci.bgn.0=z ci.bgn.z=i End If ccount.bgn>0 Then braces=1 End Otherwise co=level End ol=ol||co bgnl=bgnl||bgn End Call dbg s Call dbg ol Call dbg left(copies('123456789.',10),length(s)) Call dbg bgnl Do bgi=1 To bgdata.0 If end.bgi=1 Then Do cl='' Do cii=1 To ci.bgi.0 cl=cl ci.bgi.cii End Parse Var bgdata.bgi level a e Call dbg bgi level a cl e End End Return   bm: /*--------------------------------------------------------------------- * Brace Management * for '{' create a new brace group )record level and start column * for '}' look for corresponding bg and add end column * Input: column and character ( '{' or '}' ) * Output: bgdata.* level start-column [end-column] *--------------------------------------------------------------------*/ Parse Arg oc Call dbg oc i level If oc='{' Then Do z=bgdata.0+1 bgdata.z=level i bgdata.0=z bgn=bgnmax+1 bgnmax=bgn End Else Do Do bgi=bgdata.0 To 1 By -1 If level=word(bgdata.bgi,1) Then Do bgdata.bgi=bgdata.bgi i end.bgi=1 Leave End End bgn=bgn-1 Call dbg bgdata.bgi 'bgn='bgn End Return   expand: /*--------------------------------------------------------------------- * Expand a brace group in string s *--------------------------------------------------------------------*/ Parse Arg bgi Parse Var bgdata.bgi . start end clist=start clist end If words(clist)>0 Then Do /* commas in brace group */ left=left(s,start-1) /* part of s before the '{' */ rite=substr(s,end+1) /* part of s after the '}' */ Do k=1 To words(clist)-1 /* Loop over comma positions */ a=word(clist,k) /* start position */ e=word(clist,k+1) /* end position */ choice.k=substr(s,a+1,e-a-1) /* one of the choices */ z=s.ita.0+1 /* add new string to next set */ s.ita.z=left||choice.k||rite /* construct new string */ s.ita.0=z todo=1 /* maybe more to be done */ End End Else Do /* no commas */ z=s.ita.0+1 /* copy string as is to next set*/ s.ita.z=s s.ita.0=z End Do zz=1 To s.ita.0 Call dbg zz s.ita.zz End Return   dbg: /* handle debug output */ If dbg<>'' Then /* argument given */ Say arg(1) /* show on screen */ Call lineout oid,arg(1) /* write to file */ Return
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#Kotlin
Kotlin
fun sameDigits(n: Int, b: Int): Boolean { var n2 = n val f = n % b while (true) { n2 /= b if (n2 > 0) { if (n2 % b != f) { return false } } else { break } } return true }   fun isBrazilian(n: Int): Boolean { if (n < 7) return false if (n % 2 == 0) return true for (b in 2 until n - 1) { if (sameDigits(n, b)) { return true } } return false }   fun isPrime(n: Int): Boolean { if (n < 2) return false if (n % 2 == 0) return n == 2 if (n % 3 == 0) return n == 3 var d = 5 while (d * d <= n) { if (n % d == 0) return false d += 2 if (n % d == 0) return false d += 4 } return true }   fun main() { val bigLim = 99999 val limit = 20 for (kind in ",odd ,prime".split(',')) { var quiet = false println("First $limit ${kind}Brazilian numbers:") var c = 0 var n = 7 while (c < bigLim) { if (isBrazilian(n)) { if (!quiet) print("%,d ".format(n)) if (++c == limit) { print("\n\n") quiet = true } } if (quiet && kind != "") continue when (kind) { "" -> n++ "odd " -> n += 2 "prime" -> { while (true) { n += 2 if (isPrime(n)) break } } } } if (kind == "") println("The %,dth Brazilian number is: %,d".format(bigLim + 1, n)) } }
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#J
J
require 'dates format' NB. J6.x require 'dates general/misc/format' NB. J7.x calBody=: (1 1 }. _1 _1 }. ":)@(-@(<.@%&22)@[ ]\ calendar@]) calTitle=: (<: - 22&|)@[ center '[Insert Snoopy here]' , '' ,:~ ":@] formatCalendar=: calTitle , calBody
http://rosettacode.org/wiki/Brownian_tree
Brownian tree
Brownian tree You are encouraged to solve this task according to the task description, using any language you may know. Task Generate and draw a   Brownian Tree. A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes. The initial "seed" is placed somewhere within the field. Where is not particularly important; it could be randomized, or it could be a fixed point. Particles are injected into the field, and are individually given a (typically random) motion pattern. When a particle collides with the seed or tree, its position is fixed, and it's considered to be part of the tree. Because of the lax rules governing the random nature of the particle's placement and motion, no two resulting trees are really expected to be the same, or even necessarily have the same general shape.
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
canvasdim = 1000; n = 0.35*canvasdim^2; canvas = ConstantArray[0, {canvasdim, canvasdim}]; init = Floor@(0.5*{canvasdim, canvasdim}); (*RandomInteger[canvasdim,2]*) canvas[[init[[1]], init[[2]]]] = 1; (*1st particle initialized to midpoint*)   Monitor[ (*Provides real-time intermediate result monitoring*) Do[ particle = RandomInteger[canvasdim, 2]; While[True, ds = RandomInteger[{-1, 1}, 2]; While[ (*New Particle Domain Limit Section*)  !And @@ (0 < (particle + ds)[[#]] <= canvasdim & /@ {1, 2}), particle = RandomInteger[canvasdim, 2]; ]; (* Particle Aggregation Section *) If[canvas[[(particle + ds)[[1]], (particle + ds)[[2]]]] > 0, canvas[[particle[[1]], particle[[2]]]] = i; Break[], particle += ds ]; ], {i, n}], {i, (particle + ds), MatrixPlot@canvas} ] MatrixPlot[canvas,FrameTicks->None,ColorFunction->"DarkRainbow",ColorRules->{0 -> None}]
http://rosettacode.org/wiki/Bulls_and_cows
Bulls and cows
Bulls and Cows Task Create a four digit random number from the digits   1   to   9,   without duplication. The program should:   ask for guesses to this number   reject guesses that are malformed   print the score for the guess The score is computed as: The player wins if the guess is the same as the randomly chosen number, and the program ends. A score of one bull is accumulated for each digit in the guess that equals the corresponding digit in the randomly chosen initial number. A score of one cow is accumulated for each digit in the guess that also appears in the randomly chosen number, but in the wrong position. Related tasks   Bulls and cows/Player   Guess the number   Guess the number/With Feedback   Mastermind
#Euphoria
Euphoria
include std\text.e include std\os.e include std\sequence.e include std\console.e   sequence bcData = {0,0} --bull,cow score for the player sequence goalNum = { {0,0,0,0}, {0,0,0,0}, 0} --computer's secret number digits (element 1), marked as bull/cow --indexes in element 2, integer value of it in element 3 sequence currentGuess = { {0,0,0,0}, {0,0,0,0}, 0} --player's guess, same format as goalNum sequence removeChars = 0 & " 0\r\t\n" --characters to trim (remove) from user's input. \r, \t are single escaped characters, --0 is ascii 0x0 and number zero is ascii 48, or 0x30. The rest are wysiwyg integer tries = 0 --track number of tries to guess the number sequence bcStrings ={"bull", "cow"} --stores singular and/or plural strings depending on score in bcData   goalNum[1] = rand( {9,9,9,9} ) --rand function works on objects. here it outputs into each sequence element. goalNum[3] = goalNum[1][1] * 1000 + goalNum[1][2] * 100 + goalNum[1][3] * 10 + goalNum[1][4] --convert digits to an integer --and store it   procedure getInputAndProcess(integer stage = 1) --object = 1 sets default value for the parameter if it isn't specified   goalNum[2][1..4] = 0 --{0,0,0,0} --set these to unscaned (0) since the scanning will start over. currentGuess[1][1..4] = 0 --{0,0,0,0} --these too, or they will contain old marks currentGuess[2][1..4] = 0 tries += 1 --equivalent to tries = tries + 1, but faster and shorter to write bcData[1..2] = 0 -- {0,0}   if stage <= 1 then --if this process was run for the first time or with no parameters, then.. puts(1,"The program has thought of a four digit number using only digits 1 to 9.\nType your guess and press enter.\n") end if   while 1 label "guesscheck" do --labels can be used to specify a jump point from exit or retry, and help readability currentGuess[1] = trim(gets(0), removeChars) --get user input, trim unwanted characters from it, store it in currentGuess[1] currentGuess[1] = mapping( currentGuess[1], {49,50,51,52,53,54,55,56,57}, {1,2,3,4,5,6,7,8,9} ) --convert ascii codes to -- integer digits they represent integer tempF = find('0',currentGuess[1]) if length(currentGuess[1]) != 4 or tempF != 0 then --if the input string is now more than 4 characters/integers, --the input won't be used. puts(1,"You probably typed too many digits or a 0. Try typing a new 4 digit number with only numbers 1 through 9.\n") retry "guesscheck" else exit "guesscheck" end if end while --convert separate digits to the one integer they represent and store it, like with goalNum[3] currentGuess[3] = currentGuess[1][1] * 1000 + currentGuess[1][2] * 100 + currentGuess[1][3] * 10 + currentGuess[1][4] --convert digits to the integer they represent, to print to a string later   --check for bulls for i = 1 to 4 do if goalNum[1][i] = currentGuess[1][i] then goalNum[2][i] = 1 currentGuess[2][i] = 1 bcData[1] += 1 end if end for   --check for cows, but not slots marked as bulls or cows already. for i = 1 to 4 label "iGuessElem"do --loop through each guessed digit for j = 1 to 4 label "jGoalElem" do --but first go through each goal digit, comparing the first guessed digit, --and then the other guessed digits 2 through 4   if currentGuess[2][i] = 1 then --if the guessed digit we're comparing right now has been marked as bull or cow already continue "iGuessElem" --skip to the next guess digit without comparing this guess digit to the other goal digits end if   if goalNum[2][j] = 1 then --if the goal digit we're comparing to right now has been marked as a bull or cow already continue "jGoalElem" --skip to the next goal digit end if   if currentGuess[1][i] = goalNum[1][j] then --if the guessed digit is the same as the goal one, --it won't be a bull, so it's a cow bcData[2] += 1 --score one more cow goalNum[2][j] = 1 --mark this digit as a found cow in the subsequence that stores 0's or 1's as flags continue "iGuessElem" --skip to the next guess digit, so that this digit won't try to check for --matches(cow) with other goal digits end if   end for --this guess digit was compared to one goal digit , try comparing this guess digit with the next goal digit end for --this guess digit was compared with all goal digits, compare the next guess digit to all the goal digits   if bcData[1] = 1 then --uses singular noun when there is score of 1, else plural bcStrings[1] = "bull" else bcStrings[1] = "bulls" end if   if bcData[2] = 1 then --the same kind of thing as above block bcStrings[2] = "cow" else bcStrings[2] = "cows" end if   if bcData[1] < 4 then --if less than 4 bulls were found, the player hasn't won, else they have... printf(1, "Guess #%d : You guessed %d . You found %d %s, %d %s. Type new guess.\n", {tries, currentGuess[3], bcData[1], bcStrings[1], bcData[2], bcStrings[2]} ) getInputAndProcess(2) else --else they have won and the procedure ends printf(1, "The number was %d. You guessed %d in %d tries.\n", {goalNum[3], currentGuess[3], tries} ) any_key()--wait for keypress before closing console window. end if   end procedure --run the procedure getInputAndProcess(1)      
http://rosettacode.org/wiki/Caesar_cipher
Caesar cipher
Task Implement a Caesar cipher, both encoding and decoding. The key is an integer from 1 to 25. This cipher rotates (either towards left or right) the letters of the alphabet (A to Z). The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A). So key 2 encrypts "HI" to "JK", but key 20 encrypts "HI" to "BC". This simple "mono-alphabetic substitution cipher" provides almost no security, because an attacker who has the encoded message can either use frequency analysis to guess the key, or just try all 25 keys. Caesar cipher is identical to Vigenère cipher with a key of length 1. Also, Rot-13 is identical to Caesar cipher with key 13. Related tasks Rot-13 Substitution Cipher Vigenère Cipher/Cryptanalysis
#D
D
import std.stdio, std.traits;   S rot(S)(in S s, in int key) pure nothrow @safe if (isSomeString!S) { auto res = s.dup;   foreach (immutable i, ref c; res) { if ('a' <= c && c <= 'z') c = ((c - 'a' + key) % 26 + 'a'); else if ('A' <= c && c <= 'Z') c = ((c - 'A' + key) % 26 + 'A'); } return res; }   void main() @safe { enum key = 3; immutable txt = "The five boxing wizards jump quickly"; writeln("Original: ", txt); writeln("Encrypted: ", txt.rot(key)); writeln("Decrypted: ", txt.rot(key).rot(26 - key)); }
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#PureBasic
PureBasic
Define f.d=1.0, e.d=1.0, e0.d=e, n.i=1 LOOP: f*n : e+1.0/f If e-e0>=1.0e-15 : e0=e : n+1 : Goto LOOP : EndIf Debug "e="+StrD(e,15)
http://rosettacode.org/wiki/Calculating_the_value_of_e
Calculating the value of e
Task Calculate the value of   e. (e   is also known as   Euler's number   and   Napier's constant.) See details: Calculating the value of e
#Python
Python
import math #Implementation of Brother's formula e0 = 0 e = 2 n = 0 fact = 1 while(e-e0 > 1e-15): e0 = e n += 1 fact *= 2*n*(2*n+1) e += (2.*n+2)/fact   print "Computed e = "+str(e) print "Real e = "+str(math.e) print "Error = "+str(math.e-e) print "Number of iterations = "+str(n)
http://rosettacode.org/wiki/Bulls_and_cows/Player
Bulls and cows/Player
Task Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts. One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equivalent score to how your last guess was scored. Your next guess can be any number from the pruned list. Either you guess correctly or run out of numbers to guess, which indicates a problem with the scoring. Related tasks   Bulls and cows   Guess the number   Guess the number/With Feedback (Player)
#SenseTalk
SenseTalk
set the remoteWorkInterval to .001 -- optional repeat forever repeat forever set description to "Enter a 4 digit number" & newline & "- zero's excluded" & newline & "- each digit should be unique" & newline Ask "Enter a Number" title "Bulls & Cows (Player)" message description put it into num if num is "" Answer "" with "Play" or "Quit" title "Quit Bulls & Cows (Player)?" if it is "Quit" exit all end if end if set startTime to now if number of characters in num is 4 if character 1 of num is not equal to character 2 of num if character 1 of num is not equal to character 3 of num if character 1 of num is not equal to character 4 of num if character 2 of num is not equal to character 3 of num if character 2 of num is not equal to character 4 of num if character 3 of num is not equal to character 4 of num if num does not contain 0 exit repeat end if end if end if end if end if end if end if end if end repeat set guess to 1111 set lastBullQty to 0 set digitLocation to 1 set cowVals to empty repeat forever set score to { bulls: { qty: 0, values: {} }, cows: { qty: 0, values: {} } } repeat the number of characters in num times if character the counter of guess is equal to character the counter of num add 1 to score.bulls.qty insert character the counter of guess into score.bulls.values else if num contains character the counter of guess if character the counter of guess is not equal to character the counter of num if score.bulls.values does not contain character the counter of guess and score.cows.values does not contain character the counter of guess add 1 to score.cows.qty if cowVals.(character the counter of guess) is empty set cowVals.(character the counter of guess) to false end if end if end if end if end if end repeat if guess is equal to num put now - startTime into elapsedTime set displayMessage to "Your Number:" && num & newline & "Guessed Number:" && guess & newline & newline & "Time Elapsed:" && elapsedTime.seconds && seconds Answer displayMessage with "Play Again" or "Quit" title "Done!" if it is "Quit" exit all end if exit repeat else if the counter is greater than 1 if score.bulls.qty is not lastBullQty if score.bulls.qty is greater than lastBullQty if digitLocation is not 4 -- move on to the next digit add 1 to digitLocation else set digitLocation to 1 end if repeat for each (key,value) in cowVals if score.bulls.values contains key set cowVals.(key) to "bull" else set cowVals.(key) to false end if end repeat else subtract 1 from character digitLocation of guess -- stay on current digit end if set lastBullQty to score.bulls.qty -- save bull qty else -- score.bulls.qty = lastBullQty set cow_guessed to false if cowVals is not empty repeat for each (key,value) in cowVals if value is false set cow_guessed to true set cowVals.(key) to true if digitLocation is not 1 set character digitLocation of guess to key exit repeat else add 1 to character digitLocation of guess exit repeat end if end if end repeat if cow_guessed is false if character digitLocation of guess is greater than 9 set character digitLocation of guess to 0 -- reset the current digit end if add 1 to character digitLocation of guess -- increment the current digit end if else add 1 to character digitLocation of guess -- increment the current digit end if end if end if end if end repeat end repeat
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers
Calendar - for "REAL" programmers
Task Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented   entirely without lowercase. Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide. (Hint: manually convert the code from the Calendar task to all UPPERCASE) This task also is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." Moreover this task is further inspired by the long lost corollary article titled: "Real programmers think in UPPERCASE"! Note: Whereas today we only need to worry about ASCII, UTF-8, UTF-16, UTF-32, UTF-7 and UTF-EBCDIC encodings, in the 1960s having code in UPPERCASE was often mandatory as characters were often stuffed into 36-bit words as 6 lots of 6-bit characters. More extreme words sizes include 60-bit words of the CDC 6000 series computers. The Soviets even had a national character set that was inclusive of all 4-bit, 5-bit, 6-bit & 7-bit depending on how the file was opened... And one rogue Soviet university went further and built a 1.5-bit based computer. Of course... as us Boomers have turned into Geezers we have become HARD OF HEARING, and suffer from chronic Presbyopia, hence programming in UPPERCASE is less to do with computer architecture and more to do with practically. :-) For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. FYI: a nice ASCII art file of Snoopy can be found at textfiles.com. Save with a .txt extension. Trivia: The terms uppercase and lowercase date back to the early days of the mechanical printing press. Individual metal alloy casts of each needed letter, or punctuation symbol, were meticulously added to a press block, by hand, before rolling out copies of a page. These metal casts were stored and organized in wooden cases. The more often needed minuscule letters were placed closer to hand, in the lower cases of the work bench. The less often needed, capitalized, majuscule letters, ended up in the harder to reach upper cases.
#X86_Assembly
X86 Assembly
.MODEL TINY .CODE .486 ORG 100H ;.COM FILES START HERE YEAR EQU 1969 ;DISPLAY CALENDAR FOR SPECIFIED YEAR START: MOV CX, 61 ;SPACE(61); TEXT(0, "[SNOOPY]"); CRLF(0) CALL SPACE MOV DX, OFFSET SNOOPY CALL TEXT MOV CL, 63 ;SPACE(63); INTOUT(0, YEAR); CRLF(0); CRLF(0) CALL SPACE MOV AX, YEAR CALL INTOUT CALL CRLF CALL CRLF   MOV DI, 1 ;FOR MONTH:= 1 TO 12 DO DI=MONTH L22: XOR SI, SI ; FOR COL:= 0 TO 6-1 DO SI=COL L23: MOV CL, 5 ; SPACE(5) CALL SPACE MOV DX, DI ; TEXT(0, MONAME(MONTH+COL-1)); SPACE(7); DEC DX ; DX:= (MONTH+COL-1)*10+MONAME ADD DX, SI IMUL DX, 10 ADD DX, OFFSET MONAME CALL TEXT MOV CL, 7 CALL SPACE CMP SI, 5 ; IF COL<5 THEN SPACE(1); JGE L24 MOV CL, 1 CALL SPACE INC SI JMP L23 L24: CALL CRLF   MOV SI, 6 ; FOR COL:= 0 TO 6-1 DO L25: MOV DX, OFFSET SUMO ; TEXT(0, "SU MO TU WE TH FR SA"); CALL TEXT DEC SI ; IF COL<5 THEN SPACE(2); JE L27 MOV CL, 2 CALL SPACE JMP L25 L27: CALL CRLF   XOR SI, SI ;FOR COL:= 0 TO 6-1 DO L28: MOV BX, DI ;DAY OF FIRST SUNDAY OF MONTH (CAN BE NEGATIVE) ADD BX, SI ;DAY(COL):= 1 - WEEKDAY(YEAR, MONTH+COL, 1); MOV BP, YEAR   ;DAY OF WEEK FOR FIRST DAY OF THE MONTH (0=SUN 1=MON..6=SAT) CMP BL, 2 ;IF MONTH<=2 THEN JG L3 ADD BL, 12 ; MONTH:= MONTH+12; DEC BP ; YEAR:= YEAR-1; L3: ;REM((1-1 + (MONTH+1)*26/10 + YEAR + YEAR/4 + YEAR/100*6 + YEAR/400)/7) INC BX ;MONTH IMUL AX, BX, 26 MOV CL, 10 CWD IDIV CX MOV BX, AX MOV AX, BP ;YEAR ADD BX, AX SHR AX, 2 ADD BX, AX MOV CL, 25 CWD IDIV CX IMUL DX, AX, 6 ;YEAR/100*6 ADD BX, DX SHR AX, 2 ;YEAR/400 ADD AX, BX MOV CL, 7 CWD IDIV CX NEG DX INC DX MOV [SI+DAY], DL ;COL+DAY INC SI CMP SI, 5 JLE L28   MOV BP, 6 ;FOR LINE:= 0 TO 6-1 DO BP=LINE L29: XOR SI, SI ; FOR COL:= 0 TO 6-1 DO SI=COL L30: MOV BX, DI ; DAYMAX:= DAYS(MONTH+COL); MOV BL, [BX+SI+DAYS]   ;IF MONTH+COL=2 & (REM(YEAR/4)=0 & REM(YEAR/100)#0 ! REM(YEAR/400)=0) THEN MOV AX, DI ;MONTH ADD AX, SI CMP AL, 2 JNE L32 MOV AX, YEAR TEST AL, 03H JNE L32 MOV CL,100 CWD IDIV CX TEST DX, DX JNE L31 TEST AL, 03H JNE L32 L31: INC BX ;IF FEBRUARY AND LEAP YEAR THEN ADD A DAY L32: MOV DX, 7 ;FOR WEEKDAY:= 0 TO 7-1 DO L33: MOVZX AX, [SI+DAY] ; IF DAY(COL)>=1 & DAY(COL)<=DAYMAX THEN CMP AL, 1 JL L34 CMP AL, BL JG L34 CALL INTOUT ; INTOUT(0, DAY(COL)); CMP AL, 10 ; IF DAY(COL)<10 THEN SPACE(1); LEFT JUSTIFY JGE L36 MOV CL, 1 CALL SPACE JMP L36 L34: MOV CL, 2 ; ELSE SPACE(2); CALL SPACE ; SUPPRESS OUT OF RANGE DAYS L36: MOV CL, 1 ; SPACE(1); CALL SPACE INC BYTE PTR [SI+DAY] ; DAY(COL):= DAY(COL)+1; DEC DX ;NEXT WEEKDAY JNE L33   CMP SI, 5 ;IF COL<5 THEN SPACE(1); JGE L37 MOV CL, 1 CALL SPACE INC SI JMP L30 L37: CALL CRLF   DEC BP ;NEXT LINE DOWN JNE L29 CALL CRLF   ADD DI, 6 ;NEXT 6 MONTHS CMP DI, 12 JLE L22 RET   ;DISPLAY POSITIVE INTEGER IN AX INTOUT: PUSHA MOV BX, 10 XOR CX, CX NO10: CWD IDIV BX PUSH DX INC CX TEST AX, AX JNE NO10 NO20: MOV AH, 02H POP DX ADD DL, '0' INT 21H LOOP NO20 POPA RET   ;DISPLAY CX SPACE CHARACTERS SPACE: PUSHA SP10: MOV AH, 02H MOV DL, 20H INT 21H LOOP SP10 POPA RET   ;START A NEW LINE CRLF: MOV DX, OFFSET LCRLF   ;DISPLAY STRING AT DX TEXT: MOV AH, 09H INT 21H RET   SNOOPY DB "[SNOOPY]" LCRLF DB 0DH, 0AH, '$' MONAME DB " JANUARY $ FEBRUARY$ MARCH $ APRIL $ MAY $ JUNE $" DB " JULY $ AUGUST $SEPTEMBER$ OCTOBER$ NOVEMBER$ DECEMBER$" SUMO DB "SU MO TU WE TH FR SA$" DAYS DB 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 DAY DB  ?, ?, ?, ?, ?, ? END START
http://rosettacode.org/wiki/Call_a_function
Call a function
Task Demonstrate the different syntax and semantics provided for calling a function. This may include:   Calling a function that requires no arguments   Calling a function with a fixed number of arguments   Calling a function with optional arguments   Calling a function with a variable number of arguments   Calling a function with named arguments   Using a function in statement context   Using a function in first-class context within an expression   Obtaining the return value of a function   Distinguishing built-in functions and user-defined functions   Distinguishing subroutines and functions   Stating whether arguments are passed by value or by reference   Is partial application possible and how This task is not about defining functions.
#Haskell
Haskell
  -- Calling a function with a fixed number of arguments multiply x y = x * y multiply 10 20 -- returns 200   -- Calling a function that requires no arguments -- Normally, you use constant instead of function without arguments: twopi = 6.28 -- But you can also pass special value as the first argument indicating function call: twopi () = 6.28 -- definition twopi :: Num a => () -> a -- its type twopi () -- returns 6.28   -- Partial application and auto-currying is built-in. multiply_by_10 = (10 * ) map multiply_by_10 [1, 2, 3] -- [10, 20, 30] multiply_all_by_10 = map multiply_by_10 multiply_all_by_10 [1, 2, 3] -- [10, 20, 30]   -- TODO: -- Calling a function with optional arguments -- Calling a function with a variable number of arguments -- Calling a function with named arguments -- Using a function in statement context -- Using a function in first-class context within an expression -- Obtaining the return value of a function -- Distinguishing built-in functions and user-defined functions -- Distinguishing subroutines and functions -- Stating whether arguments are passed by value or by reference  
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C_{n}={\frac {1}{n+1}}{2n \choose n}={\frac {(2n)!}{(n+1)!\,n!}}\qquad {\mbox{ for }}n\geq 0.} Or recursively: C 0 = 1 and C n + 1 = ∑ i = 0 n C i C n − i for  n ≥ 0 ; {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n+1}=\sum _{i=0}^{n}C_{i}\,C_{n-i}\quad {\text{for }}n\geq 0;} Or alternatively (also recursive): C 0 = 1 and C n = 2 ( 2 n − 1 ) n + 1 C n − 1 , {\displaystyle C_{0}=1\quad {\mbox{and}}\quad C_{n}={\frac {2(2n-1)}{n+1}}C_{n-1},} Task Implement at least one of these algorithms and print out the first 15 Catalan numbers with each. Memoization   is not required, but may be worth the effort when using the second method above. Related tasks Catalan numbers/Pascal's triangle Evaluate binomial coefficients
#MATLAB_.2F_Octave
MATLAB / Octave
function n = catalanNumber(n) for i = (1:length(n)) n(i) = (1/(n(i)+1))*nchoosek(2*n(i),n(i)); end end
http://rosettacode.org/wiki/Brace_expansion
Brace expansion
Brace expansion is a type of parameter expansion made popular by Unix shells, where it allows users to specify multiple similar string parameters without having to type them all out. E.g. the parameter enable_{audio,video} would be interpreted as if both enable_audio and enable_video had been specified. Task[edit] Write a function that can perform brace expansion on any input string, according to the following specification. Demonstrate how it would be used, and that it passes the four test cases given below. Specification In the input string, balanced pairs of braces containing comma-separated substrings (details below) represent alternations that specify multiple alternatives which are to appear at that position in the output. In general, one can imagine the information conveyed by the input string as a tree of nested alternations interspersed with literal substrings, as shown in the middle part of the following diagram: It{{em,alic}iz,erat}e{d,} parse  ―――――▶ ‌ It ⎧ ⎨ ⎩ ⎧ ⎨ ⎩ em ⎫ ⎬ ⎭ alic iz ⎫ ⎬ ⎭ erat e ⎧ ⎨ ⎩ d ⎫ ⎬ ⎭ ‌ expand  ―――――▶ ‌ Itemized Itemize Italicized Italicize Iterated Iterate input string alternation tree output (list of strings) This tree can in turn be transformed into the intended list of output strings by, colloquially speaking, determining all the possible ways to walk through it from left to right while only descending into one branch of each alternation one comes across (see the right part of the diagram). When implementing it, one can of course combine the parsing and expansion into a single algorithm, but this specification discusses them separately for the sake of clarity. Expansion of alternations can be more rigorously described by these rules: a ⎧ ⎨ ⎩ 2 ⎫ ⎬ ⎭ 1 b ⎧ ⎨ ⎩ X ⎫ ⎬ ⎭ Y X c ⟶ a2bXc a2bYc a2bXc a1bXc a1bYc a1bXc An alternation causes the list of alternatives that will be produced by its parent branch to be increased 𝑛-fold, each copy featuring one of the 𝑛 alternatives produced by the alternation's child branches, in turn, at that position. This means that multiple alternations inside the same branch are cumulative  (i.e. the complete list of alternatives produced by a branch is the string-concatenating "Cartesian product" of its parts). All alternatives (even duplicate and empty ones) are preserved, and they are ordered like the examples demonstrate  (i.e. "lexicographically" with regard to the alternations). The alternatives produced by the root branch constitute the final output. Parsing the input string involves some additional complexity to deal with escaped characters and "incomplete" brace pairs: a\\{\\\{b,c\,d} ⟶ a\\ ⎧ ⎨ ⎩ \\\{b ⎫ ⎬ ⎭ c\,d {a,b{c{,{d}}e}f ⟶ {a,b{c ⎧ ⎨ ⎩ ‌ ⎫ ⎬ ⎭ {d} e}f An unescaped backslash which precedes another character, escapes that character (to force it to be treated as literal). The backslashes are passed along to the output unchanged. Balanced brace pairs are identified by, conceptually, going through the string from left to right and associating each unescaped closing brace that is encountered with the nearest still unassociated unescaped opening brace to its left (if any). Furthermore, each unescaped comma is associated with the innermost brace pair that contains it (if any). With that in mind: Each brace pair that has at least one comma associated with it, forms an alternation (whose branches are the brace pair's contents split at its commas). The associated brace and comma characters themselves do not become part of the output. Brace characters from pairs without any associated comma, as well as unassociated brace and comma characters, as well as all characters that are not covered by the preceding rules, are instead treated as literals. For every possible input string, your implementation should produce exactly the output which this specification mandates. Please comply with this even when it's inconvenient, to ensure that all implementations are comparable. However, none of the above should be interpreted as instructions (or even recommendations) for how to implement it. Try to come up with a solution that is idiomatic in your programming language. (See #Perl for a reference implementation.) Test Cases Input (single string) Ouput (list/array of strings) ~/{Downloads,Pictures}/*.{jpg,gif,png} ~/Downloads/*.jpg ~/Downloads/*.gif ~/Downloads/*.png ~/Pictures/*.jpg ~/Pictures/*.gif ~/Pictures/*.png It{{em,alic}iz,erat}e{d,}, please. Itemized, please. Itemize, please. Italicized, please. Italicize, please. Iterated, please. Iterate, please. {,{,gotta have{ ,\, again\, }}more }cowbell! cowbell! more cowbell! gotta have more cowbell! gotta have\, again\, more cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} {}} some }{,{\\ edge \,}{ cases, {here} \\\\\} 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   Brace_expansion_using_ranges
#Ruby
Ruby
def getitem(s, depth=0) out = [""] until s.empty? c = s[0] break if depth>0 and (c == ',' or c == '}') if c == '{' and x = getgroup(s[1..-1], depth+1) out = out.product(x[0]).map{|a,b| a+b} s = x[1] else s, c = s[1..-1], c + s[1] if c == '\\' and s.size > 1 out, s = out.map{|a| a+c}, s[1..-1] end end return out, s end   def getgroup(s, depth) out, comma = [], false until s.empty? g, s = getitem(s, depth) break if s.empty? out += g case s[0] when '}' then return (comma ? out : out.map{|a| "{#{a}}"}), s[1..-1] when ',' then comma, s = true, s[1..-1] end end end   strs = <<'EOS' ~/{Downloads,Pictures}/*.{jpg,gif,png} It{{em,alic}iz,erat}e{d,}, please. {,{,gotta have{ ,\, again\, }}more }cowbell! {}} some }{,{\\{ edge, edge} \,}{ cases, {here} \\\\\} EOS   strs.each_line do |s| puts s.chomp! puts getitem(s)[0].map{|str| "\t"+str} puts end
http://rosettacode.org/wiki/Brazilian_numbers
Brazilian numbers
Brazilian numbers are so called as they were first formally presented at the 1994 math Olympiad Olimpiada Iberoamericana de Matematica in Fortaleza, Brazil. Brazilian numbers are defined as: The set of positive integer numbers where each number N has at least one natural number B where 1 < B < N-1 where the representation of N in base B has all equal digits. E.G. 1, 2 & 3 can not be Brazilian; there is no base B that satisfies the condition 1 < B < N-1. 4 is not Brazilian; 4 in base 2 is 100. The digits are not all the same. 5 is not Brazilian; 5 in base 2 is 101, in base 3 is 12. There is no representation where the digits are the same. 6 is not Brazilian; 6 in base 2 is 110, in base 3 is 20, in base 4 is 12. There is no representation where the digits are the same. 7 is Brazilian; 7 in base 2 is 111. There is at least one representation where the digits are all the same. 8 is Brazilian; 8 in base 3 is 22. There is at least one representation where the digits are all the same. and so on... All even integers 2P >= 8 are Brazilian because 2P = 2(P-1) + 2, which is 22 in base P-1 when P-1 > 2. That becomes true when P >= 4. More common: for all all integers R and S, where R > 1 and also S-1 > R, then R*S is Brazilian because R*S = R(S-1) + R, which is RR in base S-1 The only problematic numbers are squares of primes, where R = S. Only 11^2 is brazilian to base 3. All prime integers, that are brazilian, can only have the digit 1. Otherwise one could factor out the digit, therefore it cannot be a prime number. Mostly in form of 111 to base Integer(sqrt(prime number)). Must be an odd count of 1 to stay odd like primes > 2 Task Write a routine (function, whatever) to determine if a number is Brazilian and use the routine to show here, on this page; the first 20 Brazilian numbers; the first 20 odd Brazilian numbers; the first 20 prime Brazilian numbers; See also OEIS:A125134 - Brazilian numbers OEIS:A257521 - Odd Brazilian numbers OEIS:A085104 - Prime Brazilian numbers
#Lua
Lua
function sameDigits(n,b) local f = n % b n = math.floor(n / b) while n > 0 do if n % b ~= f then return false end n = math.floor(n / b) end return true end   function isBrazilian(n) if n < 7 then return false end if (n % 2 == 0) and (n >= 8) then return true end for b=2,n-2 do if sameDigits(n,b) then return true end end return false end   function isPrime(n) if n < 2 then return false end if n % 2 == 0 then return n == 2 end if n % 3 == 0 then return n == 3 end   local d = 5 while d * d <= n do if n % d == 0 then return false end d = d + 2   if n % d == 0 then return false end d = d + 4 end   return true end   function main() local kinds = {" ", " odd ", " prime "}   for i=1,3 do print("First 20" .. kinds[i] .. "Brazillion numbers:") local c = 0 local n = 7 while true do if isBrazilian(n) then io.write(n .. " ") c = c + 1 if c == 20 then print() print() break end end if i == 1 then n = n + 1 elseif i == 2 then n = n + 2 elseif i == 3 then repeat n = n + 2 until isPrime(n) end end end end   main()
http://rosettacode.org/wiki/Calendar
Calendar
Create a routine that will generate a text calendar for any year. Test the calendar by generating a calendar for the year 1969, on a device of the time. Choose one of the following devices: A line printer with a width of 132 characters. An IBM 3278 model 4 terminal (80×43 display with accented characters). Target formatting the months of the year to fit nicely across the 80 character width screen. Restrict number of lines in test output to 43. (Ideally, the program will generate well-formatted calendars for any page width from 20 characters up.) Kudos (κῦδος) for routines that also transition from Julian to Gregorian calendar. This task is inspired by Real Programmers Don't Use PASCAL by Ed Post, Datamation, volume 29 number 7, July 1983. THE REAL PROGRAMMER'S NATURAL HABITAT "Taped to the wall is a line-printer Snoopy calender for the year 1969." For further Kudos see task CALENDAR, where all code is to be in UPPERCASE. For economy of size, do not actually include Snoopy generation in either the code or the output, instead just output a place-holder. Related task   Five weekends
#Java
Java
import java.text.*; import java.util.*;   public class CalendarTask {   public static void main(String[] args) { printCalendar(1969, 3); }   static void printCalendar(int year, int nCols) { if (nCols < 1 || nCols > 12) throw new IllegalArgumentException("Illegal column width.");   Calendar date = new GregorianCalendar(year, 0, 1);   int nRows = (int) Math.ceil(12.0 / nCols); int offs = date.get(Calendar.DAY_OF_WEEK) - 1; int w = nCols * 24;   String[] monthNames = new DateFormatSymbols(Locale.US).getMonths();   String[][] mons = new String[12][8]; for (int m = 0; m < 12; m++) {   String name = monthNames[m]; int len = 11 + name.length() / 2; String format = MessageFormat.format("%{0}s%{1}s", len, 21 - len);   mons[m][0] = String.format(format, name, ""); mons[m][1] = " Su Mo Tu We Th Fr Sa"; int dim = date.getActualMaximum(Calendar.DAY_OF_MONTH);   for (int d = 1; d < 43; d++) { boolean isDay = d > offs && d <= offs + dim; String entry = isDay ? String.format(" %2s", d - offs) : " "; if (d % 7 == 1) mons[m][2 + (d - 1) / 7] = entry; else mons[m][2 + (d - 1) / 7] += entry; } offs = (offs + dim) % 7; date.add(Calendar.MONTH, 1); }   System.out.printf("%" + (w / 2 + 10) + "s%n", "[Snoopy Picture]"); System.out.printf("%" + (w / 2 + 4) + "s%n%n", year);   for (int r = 0; r < nRows; r++) { for (int i = 0; i < 8; i++) { for (int c = r * nCols; c < (r + 1) * nCols && c < 12; c++) System.out.printf("  %s", mons[c][i]); System.out.println(); } System.out.println(); } } }