| task_url
				 stringlengths 30 116 | task_name
				 stringlengths 2 86 | task_description
				 stringlengths 0 14.4k | language_url
				 stringlengths 2 53 | language_name
				 stringlengths 1 52 | code
				 stringlengths 0 61.9k | 
|---|---|---|---|---|---|
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#SPL | 
	SPL | 
	x = #.array("a")
#.output("a -> ",x[1]," ",x[2])
x = [98,0]
#.output("98 0 -> ",#.str(x)) | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Standard_ML | 
	Standard ML | 
	print (Int.toString (ord #"a") ^ "\n"); (* prints "97" *)
print (Char.toString (chr 97) ^ "\n"); (* prints "a" *) | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Stata | 
	Stata | 
	: ascii("α")
         1     2
    +-------------+
  1 |  206   177  |
    +-------------+ | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Swift | 
	Swift | 
	let c1: UnicodeScalar = "a"
println(c1.value) // prints "97"
let c2: UnicodeScalar = "π"
println(c2.value) // prints "960" | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Tailspin | 
	Tailspin | 
	 
'abc' -> $::asCodePoints -> !OUT::write
'$#10;' -> !OUT::write
'$#97;' -> !OUT::write
  | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Tcl | 
	Tcl | 
	# ASCII
puts [scan "a" %c]   ;# ==> 97
puts [format %c 97]  ;# ==> a
# Unicode is the same
puts [scan "π" %c]   ;# ==> 960
puts [format %c 960] ;# ==> π | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#TI-83_BASIC | 
	TI-83 BASIC | 
	"ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789→Str1
Disp inString(Str1,"A
Input "CODE? ",A
Disp sub(Str1,A,1 | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#TI-89_BASIC | 
	TI-89 BASIC | 
	Prgm
  Local k, s
  ClrIO
  Loop
    Disp "Press a key, or ON to exit."
    getKey() © clear buffer
    0 → k : While k = 0 : getKey() → k : EndWhile
    ClrIO
    If k ≥ 256 Then
      Disp "Not a character."
      Disp "Code: " & string(k)
    Else
 
      char(k) → s                           ©
      © char() and ord() are inverses.      ©
      Disp "Character: " & s                ©
      Disp "Code: " & string(ord(s))        ©
 
    EndIf
  EndLoop
EndPrgm | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Trith | 
	Trith | 
	"a" ord print
97 chr print | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#TUSCRIPT | 
	TUSCRIPT | 
	$$ MODE TUSCRIPT
SET character ="a", code=DECODE (character,byte)
PRINT character,"=",code | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#uBasic.2F4tH | 
	uBasic/4tH | 
	z = ORD("a") : PRINT CHR(z)    ' Prints "a" | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Ursa | 
	Ursa | 
	# outputs the character value for 'a'
out (ord "a") endl console
# outputs the character 'a' given its value
out (chr 97) endl console | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Ursala | 
	Ursala | 
	#import std
#import nat
 
chr = -: num characters
asc = -:@rlXS num characters
 
#cast %cnX
 
test = (chr97,asc`a) | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#VBA | 
	VBA | 
	Debug.Print Chr(97) 'Prints a
Debug.Print [Code("a")] ' Prints 97 | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#VBScript | 
	VBScript | 
	 
'prints a
WScript.StdOut.WriteLine Chr(97)
 
'prints 97
WScript.StdOut.WriteLine Asc("a")
  | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Vim_Script | 
	Vim Script | 
	"encoding is set to utf-8
echo char2nr("a")
"Prints 97
 
echo nr2char(97)
"Prints a | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Visual_Basic_.NET | 
	Visual Basic .NET | 
	Console.WriteLine(Chr(97)) 'Prints a
Console.WriteLine(Asc("a")) 'Prints 97 | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Vlang | 
	Vlang | 
	fn main() {
    println('a'[0]) // prints "97"
	println('π'[0]) // prints "207"
 
	s := 'aπ'
	println('string cast to bytes: ${s.bytes()}')
	for c in s {
		print('0x${c:x} ')
	}
} | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Wren | 
	Wren | 
	var cps = []
for (c in ["a", "π", "字", "🐘"]) {
    var cp = c.codePoints[0]
    cps.add(cp)
    System.print("%(c) = %(cp)")
}
System.print()
for (i in cps) {
    var c = String.fromCodePoint(i)
    System.print("%(i) = %(c)")
} | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#XLISP | 
	XLISP | 
	[1] (INTEGER->CHAR 97)
 
#\a
[2] (CHAR->INTEGER #\a)
 
97 | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#XPL0 | 
	XPL0 | 
	IntOut(0, ^a);  \(Integer Out)  displays "97" on the console (device 0)
ChOut(0, 97);   \(Character Out) displays "a" on the console (device 0) | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Z80_Assembly | 
	Z80 Assembly | 
	LD A,'a'
call &BB5a | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Zig | 
	Zig | 
	const std = @import("std");
 
const debug = std.debug;
const unicode = std.unicode;
 
test "character codes" {
    debug.warn("\n", .{});
 
    // Zig's string is just an array of bytes (u8).
    const message = "ABCabc";
 
    for (message) |val| {
        debug.warn("  '{c}' code: {} [hexa: 0x{x}]\n", .{ val, val, val });
    }
}
 
test "character (uni)codes" {
    debug.warn("\n", .{});
 
    const message = "あいうえお";
 
    const utf8_view = unicode.Utf8View.initUnchecked(message);
    var iter = utf8_view.iterator();
 
    while (iter.nextCodepoint()) |val| {
        var array: [4]u8 = undefined;
        var slice = array[0..try unicode.utf8Encode(val, &array)];
 
        debug.warn("  '{}' code: {} [hexa: U+{x}]\n", .{ slice, val, val });
    }
} | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#zkl | 
	zkl | 
	 "a".toAsc()  //-->97
(97).toChar() //-->"a" | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Zoea | 
	Zoea | 
	 
program: character_codes
  input: a
  output: 97
  | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#Zoea_Visual | 
	Zoea Visual | 
	10 PRINT CHR$ 97: REM prints a
20 PRINT CODE "a": REM prints 97 | 
| 
	http://rosettacode.org/wiki/Character_codes | 
	Character codes | 
	
Task
Given a character value in your language, print its code   (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character   'a'   (lowercase letter A)   has a code of 97 in ASCII   (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out the corresponding character.
 | 
	#ZX_Spectrum_Basic | 
	ZX Spectrum Basic | 
	10 PRINT CHR$ 97: REM prints a
20 PRINT CODE "a": REM prints 97 | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#11l | 
	11l | 
	F correct_case(string)
   R string.filter(s -> s.is_alpha()).map(s -> s.uppercase()).join(‘’)
 
F permu(String alp; num)
   R alp[num..]‘’alp[0 .< num]
 
F rotate_wheels(lalph, ralph, key)
   V newin = ralph.index(key)
   R (permu(lalph, newin), permu(ralph, newin))
 
F scramble_wheels(String =lalph, String =ralph)
   lalph = lalph[0]‘’lalph[2.<14]‘’lalph[1]‘’lalph[14..]
   ralph = ralph[1.<3]‘’ralph[4.<15]‘’ralph[3]‘’ralph[15..]‘’ralph[0]
   R (lalph, ralph)
 
F do_chao(=msg, =lalpha, =ralpha, en = 1B, show = 0B)
   msg = correct_case(msg)
   V out = ‘’
   I show
      print(‘=’ * 54)
      print((10 * ‘ ’)‘left:’(21 * ‘ ’)‘right: ’)
      print(‘=’ * 54)
      print(lalpha‘ ’ralpha" \n")
   L(l) msg
      I en
         (lalpha, ralpha) = rotate_wheels(lalpha, ralpha, l)
         out ‘’= lalpha[0]
      E
         (ralpha, lalpha) = rotate_wheels(ralpha, lalpha, l)
         out ‘’= ralpha[0]
      (lalpha, ralpha) = scramble_wheels(lalpha, ralpha)
      I show
         print(lalpha‘ ’ralpha)
   R out
 
V lalpha = ‘HXUCZVAMDSLKPEFJRIGTWOBNYQ’
V ralpha = ‘PTLNBQDEOYSFAVZKGJRIHWXUMC’
V msg = ‘WELLDONEISBETTERTHANWELLSAID’
 
print(‘L: ’lalpha)
print(‘R: ’ralpha)
print(‘I: ’msg)
V o = do_chao(msg, lalpha, ralpha, 1B, 0B)
print(‘O: ’o)
print(‘D: ’do_chao(o, lalpha, ralpha, 0B, 0B))
print()
 
do_chao(msg, lalpha, ralpha, 1B, 1B) | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Ada | 
	Ada | 
	 
with Ada.Text_IO; use Ada.Text_IO;
 
procedure chao_slices is
   type iMode is (Encrypt, Decrypt);
 
   L_Alphabet : String := "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
   R_Alphabet : String := "PTLNBQDEOYSFAVZKGJRIHWXUMC";
   plaintext  : String := "WELLDONEISBETTERTHANWELLSAID";
   ciphertext : String (1 .. plaintext'length);
   plaintext2 : String (1 .. plaintext'length);
   offset     : Natural;
 
   function IndexOf (Source : String; Value : Character) return Positive is
      Result : Positive;
 
   begin
      for I in Source'Range loop
         if Source (I) = Value then
            Result := I;
            exit;
         end if;
      end loop;
      return Result;
   end IndexOf;
 
   function Exec
     (Text : String; mode : iMode; showsteps : Boolean := False) return String
   is
      etext : String (Text'First .. Text'Last);
      temp  : String (1 .. 26);
      index : Positive;
      store : Character;
      left  : String := L_Alphabet;
      right : String := R_Alphabet;
   begin
      for I in Text'Range loop
         if showsteps then
            Put_Line (left & "  " & right);
         end if;
 
         if mode = Encrypt then
            index     := IndexOf (Source => right, Value => Text (I));
            etext (I) := left (index);
         else
            index     := IndexOf (Source => left, Value => Text (I));
            etext (I) := right (index);
         end if;
 
         exit when I = Text'Last;
 
         -- permute left
         -- The array value permutations are performed using array slices
         -- rather than explicit loops
 
         if index > 1 then
            offset                 := 26 - index;
            temp (1 .. offset + 1) := left (index .. index + offset);
 
            temp (offset + 2 .. 26) := left (1 .. index - 1);
            store                   := temp (2);
 
            temp (2 .. 13) := temp (3 .. 14);
            temp (14)      := store;
            left           := temp;
 
            -- permute right
            -- The array value permutations are performed using array slices
            -- rather than explicit loops
 
            temp (1 .. offset + 1) := right (index .. index + offset);
 
            temp (offset + 2 .. 26) := right (1 .. index - 1);
            store                   := temp (1);
 
            temp (1 .. 25) := temp (2 .. 26);
            temp (26)      := store;
            store          := temp (3);
 
            temp (3 .. 13) := temp (4 .. 14);
            temp (14)      := store;
            right          := temp;
         end if;
 
      end loop;
 
      return etext;
 
   end Exec;
begin
   Put_Line ("The original text is : " & plaintext);
   New_Line;
   Put_Line
     ("The left and right alphabets after each permutation during encryption are:");
   New_Line;
   ciphertext := Exec (plaintext, Encrypt, True);
   New_Line;
   Put_Line ("The ciphertext is : " & ciphertext);
   plaintext2 := Exec (ciphertext, Decrypt);
   New_Line;
   Put_Line ("The recovered plaintext is : " & plaintext2);
end chao_slices;
  | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#11l | 
	11l | 
	V n = 15
V t = [0] * (n + 2)
t[1] = 1
L(i) 1 .. n
   L(j) (i .< 1).step(-1)
      t[j] += t[j - 1]
   t[i + 1] = t[i]
   L(j) (i + 1 .< 1).step(-1)
      t[j] += t[j - 1]
   print(t[i + 1] - t[i], end' ‘ ’) | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#AppleScript | 
	AppleScript | 
	-- Chaocipher algorithm by J.F.Byrne 1918.
on chaocipher(input, |key|, mode)
    -- input: text to be enciphered or deciphered.
    -- |key|: script object or record with leftAlpha and rightAlpha properties, each of whose values is a shuffled alphabet text.
    -- mode: the text "encipher" or "decipher".
    script o
        property inputChars : input's characters
        property leftAlpha : |key|'s leftAlpha's characters
        property rightAlpha : |key|'s rightAlpha's characters
        property inAlpha : leftAlpha
        property outAlpha : rightAlpha
        property output : {}
    end script
 
    set alphaLen to (count o's leftAlpha)
    if ((count o's rightAlpha) ≠ alphaLen) then error
    if (mode is "encipher") then
        set {o's inAlpha, o's outAlpha} to {o's rightAlpha, o's leftAlpha}
    else if (mode is not "decipher") then
        error
    end if
    set zenith to 1
    set nadir to alphaLen div 2 + 1
    repeat with char in o's inputChars
        set char to char's contents
        set found to false
        repeat with i from 1 to alphaLen
            if (o's inAlpha's item i = char) then
                set end of o's output to o's outAlpha's item i
                set found to true
                exit repeat
            end if
        end repeat
        if (found) then
            rotate(o's leftAlpha, zenith, alphaLen, -(i - zenith))
            rotate(o's leftAlpha, zenith + 1, nadir, -1)
            rotate(o's rightAlpha, zenith, alphaLen, -i)
            rotate(o's rightAlpha, zenith + 2, nadir, -1)
        end if
    end repeat
 
    return join(o's output, "")
end chaocipher
 
on rotate(theList, l, r, amount)
    set listLength to (count theList)
    if (listLength < 2) then return
    if (l < 0) then set l to listLength + l + 1
    if (r < 0) then set r to listLength + r + 1
    if (l > r) then set {l, r} to {r, l}
    script o
        property lst : theList
        property storage : missing value
    end script
 
    set rangeLength to r - l + 1
    set amount to (rangeLength + rangeLength - amount) mod rangeLength
    if (amount is 0) then return
    set o's storage to o's lst's items l thru (l + amount - 1)
    repeat with i from (l + amount) to r
        set o's lst's item (i - amount) to o's lst's item i
    end repeat
    set j to r - amount
    repeat with i from 1 to amount
        set o's lst's item (j + i) to o's storage's item i
    end repeat
end rotate
 
on join(lst, delim)
    set astid to AppleScript's text item delimiters
    set AppleScript's text item delimiters to delim
    set txt to lst as text
    set AppleScript's text item delimiters to astid
    return txt
end join
 
-- Return a script object containing a couple of randomised alphabets to use as a choacipher key.
on makeKey()
    set lAlpha to "ABCDEFGHIJKLMNOPQRSTUVWXYZ"'s characters
    copy lAlpha to rAlpha
    script |key|
        property leftAlpha : join(shuffle(lAlpha, 1, -1), "")
        property rightAlpha : join(shuffle(rAlpha, 1, -1), "")
    end script
 
    return |key|
end makeKey
 
-- Fisher-Yates (aka Durstenfeld, aka Knuth) shuffle.
on shuffle(theList, l, r)
    set listLength to (count theList)
    if (listLength < 2) then return array
    if (l < 0) then set l to listLength + l + 1
    if (r < 0) then set r to listLength + r + 1
    if (l > r) then set {l, r} to {r, l}
    script o
        property lst : theList
    end script
 
    repeat with i from l to (r - 1)
        set j to (random number from i to r)
        set v to o's lst's item i
        set o's lst's item i to o's lst's item j
        set o's lst's item j to v
    end repeat
 
    return theList
end shuffle
 
-- Demo using the two-alphabet key from the Rubin paper and another generated at random.
-- Decription must be with the key that was used for the encription.
on demo(originalText)
    set key1 to {leftAlpha:"HXUCZVAMDSLKPEFJRIGTWOBNYQ", rightAlpha:"PTLNBQDEOYSFAVZKGJRIHWXUMC"}
    set key2 to makeKey()
    set enciphered to chaocipher(originalText, key1, "encipher")
    set doubleEnciphered to chaocipher(enciphered, key2, "encipher")
    set deDoubleEnciphered to chaocipher(doubleEnciphered, key2, "decipher")
    set deciphered to chaocipher(deDoubleEnciphered, key1, "decipher")
    return join({"Original text = " & originalText, ¬
        "Enciphered = " & enciphered, "Double enciphered = " & doubleEnciphered, ¬
        "De-double enciphered = " & deDoubleEnciphered, "Deciphered  = " & deciphered}, linefeed)
end demo
demo("WELLDONEISBETTERTHANWELLSAID") | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#360_Assembly | 
	360 Assembly | 
	CATALAN  CSECT                         
         USING  CATALAN,R13,R12
SAVEAREA B      STM-SAVEAREA(R15)
         DC     17F'0'
         DC     CL8'CATALAN'
STM      STM    R14,R12,12(R13)
         ST     R13,4(R15)
         ST     R15,8(R13)
         LR     R13,R15
         LA     R12,4095(R13)
         LA     R12,1(R12)
*        ----   CODE
         LA     R0,1
         ST     R0,T            t(1)=1
         LA     R4,0            ix:i=1
         LA     R6,1            by 1
         LH     R7,N            to n 
LOOPI    BXH    R4,R6,ENDLOOPI  loop i
         LR     R5,R4           ix:j=i+1
         LA     R5,2(R5)        i+2
         LA     R8,0
         BCTR   R8,0            by -1 
         LA     R9,1            to 2
LOOP1J   BXLE   R5,R8,ENLOOP1J  loop j
         LR     R10,R5          j
         BCTR   R10,0
         SLA    R10,2
         L      R2,T(R10)       r2=t(j)  
         LR     R1,R10          j
         SH     R1,=H'4'
         L      R3,T(R1)        r3=t(j-1)
         AR     R2,R3           r2=r2+r3 
         ST     R2,T(R10)       t(j)=t(j)+t(j-1)
         B      LOOP1J
ENLOOP1J EQU    *
         LR     R1,R4           i
         BCTR   R1,0
         SLA    R1,2
         L      R3,T(R1)        t(i)
         LA     R1,4(R1)
         ST     R3,T(R1)        t(i+1)
         LR     R5,R4           ix:j=i+2
         LA     R5,3(R5)        i+3
         LA     R8,0
         BCTR   R8,0            by -1 
         LA     R9,1            to 2
LOOP2J   BXLE   R5,R8,ENLOOP2J  loop j
         LR     R10,R5          j
         BCTR   R10,0
         SLA    R10,2
         L      R2,T(R10)       r2=t(j)  
         LR     R1,R10          j
         SH     R1,=H'4'
         L      R3,T(R1)        r3=t(j-1)
         AR     R2,R3           r2=r2+r3 
         ST     R2,T(R10)       t(j)=t(j)+t(j-1)
         B      LOOP2J
ENLOOP2J EQU    *
         LR     R1,R4           i
         BCTR   R1,0
         SLA    R1,2
         L      R2,T(R1)        t(i)
         LA     R1,4(R1)
         L      R3,T(R1)        t(i+1)
         SR     R3,R2
         CVD    R3,P            
         UNPK   Z,P
         MVC    C,Z
         OI     C+L'C-1,X'F0'
         MVC    WTOBUF(8),C+8
         WTO    MF=(E,WTOMSG)		  
         B      LOOPI
ENDLOOPI EQU    *
*        ----   END CODE
         CNOP   0,4
         L      R13,4(0,R13)
         LM     R14,R12,12(R13)
         XR     R15,R15
         BR     R14
*        ----   DATA
N        DC     H'15'
T        DC     17F'0'
P        DS     PL8
Z        DS     ZL16
C        DS     CL16
WTOMSG   DS     0F
         DC     H'80'
         DC     H'0'
WTOBUF   DC     CL80' '
         YREGS  
         END | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#Action.21 | 
	Action! | 
	INCLUDE "D2:REAL.ACT" ;from the Action! Tool Ki
 
DEFINE PTR="CARD"
DEFINE REALSIZE="6"
 
PTR FUNC GetItemAddr(PTR buf BYTE i)
RETURN (buf+REALSIZE*i)
 
PROC Main()
  DEFINE COUNT="15"
  BYTE ARRAY buf(102) ;(COUNT+2)*REALSIZE
  REAL POINTER r1,r2
  REAL c
  BYTE i,j
 
  Put(125) PutE() ;clear the screen
 
  r1=GetItemAddr(buf,1)
  IntToReal(1,r1)
 
  FOR i=1 TO COUNT
  DO
    j=i+1
    WHILE j>=2
    DO
      r1=GetItemAddr(buf,j)
      r2=GetItemAddr(buf,j-1)
      RealAdd(r1,r2,r1) ;t(j)==+t(j-1)
      j==-1
    OD
    r1=GetItemAddr(buf,i)
    r2=GetItemAddr(buf,i+1)
    RealAssign(r1,r2) ;t(i+1)=t(i)
 
    j=i+2
    WHILE j>=2
    DO
      r1=GetItemAddr(buf,j)
      r2=GetItemAddr(buf,j-1)
      RealAdd(r1,r2,r1) ;t(j)==+t(j-1)
      j==-1
    OD
    r1=GetItemAddr(buf,i)
    r2=GetItemAddr(buf,i+1)
    RealSub(r2,r1,c) ;c=t(i+1)-t(i)
    PrintF("C(%B)=",i) PrintRE(c)
  OD
RETURN | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Arc | 
	Arc | 
	(= lshift '((0 1) (2 14) (1 2) (14 26)))
(= rshift '((1 3) (4 15) (3 4) (15 26) (0 1)))
 
(= rot (fn (alpha shift)
  (let shift (mod shift 26)
    (string (cut alpha shift) (cut alpha 0 shift)))))
 
(= scramble-wheel (fn (alpha moves)
  (= oput '())
  (up i 0 (- (len moves) 1)
      (push (cut alpha ((moves i) 0) ((moves i) 1)) oput))
  (= oput (string (rev oput)))))
 
(= chaocipher (fn (left right msg (o crypted) (o dec?))
  (unless crypted
    (prn "Encoding " msg " with chaocipher")
    (prn left " " right))
  (when dec? (swap left right))
    (= offset ((positions (msg 0) right) 0))
    (= left (rot left offset))
    (= right (rot right offset))
    (push (cut left 0 1) crypted)
  (when dec? (swap left right))
  (prn (scramble-wheel left lshift)
   " " (scramble-wheel right rshift))
  (if (> (len msg) 1)
      (chaocipher (scramble-wheel left lshift)
             (scramble-wheel right rshift)
                  (cut msg 1) crypted dec?)
      (string (rev crypted)))))
 
(chaocipher "HXUCZVAMDSLKPEFJRIGTWOBNYQ" "PTLNBQDEOYSFAVZKGJRIHWXUMC"
            "WELLDONEISBETTERTHANWELLSAID")
(chaocipher "HXUCZVAMDSLKPEFJRIGTWOBNYQ" "PTLNBQDEOYSFAVZKGJRIHWXUMC"
            "OAHQHCNYNXTSZJRRHJBYHQKSOUJY" nil 1)
  | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#Ada | 
	Ada | 
	with Ada.Text_IO, Pascal;
 
procedure Catalan is
 
   Last: Positive := 15;   
   Row: Pascal.Row := Pascal.First_Row(2*Last+1);
 
begin
   for I in 1 .. Last loop
      Row := Pascal.Next_Row(Row);
      Row := Pascal.Next_Row(Row);
      Ada.Text_IO.Put(Integer'Image(Row(I+1)-Row(I+2)));
   end loop;
end Catalan; | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#ALGOL_68 | 
	ALGOL 68 | 
	INT n = 15;
[ 0 : n + 1 ]INT t;
t[0] := 0;
t[1] := 1;
FOR i TO n DO
    FOR j FROM i   BY -1 TO 2 DO t[j] := t[j] + t[j-1] OD;
    t[i+1] := t[i];
    FOR j FROM i+1 BY -1 TO 2 DO t[j] := t[j] + t[j-1] OD;
    print( ( whole( t[i+1] - t[i], 0 ), " " ) )
OD | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#11l | 
	11l | 
	V dog = ‘Benjamin’
V Dog = ‘Samba’
V DOG = ‘Bernie’
print(‘The three dogs are named ’dog‘, ’Dog‘ and ’DOG‘.’) | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#AutoHotkey | 
	AutoHotkey | 
	LeftW := "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
RghtW := "PTLNBQDEOYSFAVZKGJRIHWXUMC"
 
PlainText    := "WELLDONEISBETTERTHANWELLSAID"
CipherText    := Chao_Cipher(PlainText, LeftW, RghtW)     ; "OAHQHCNYNXTSZJRRHJBYHQKSOUJY"
DecipherText:= Chao_Decipher(CipherText, LeftW, RghtW)    ; "WELLDONEISBETTERTHANWELLSAID"
 
MsgBox % Result := "Original text:`t" PlainText "`nCipher text:`t" CipherText "`nDecipher text:`t" DecipherText
return
;-------------------------------------------
Chao_Cipher(PT, LeftW, RghtW){
    oRght:=StrSplit(RghtW), oLeft:=StrSplit(LeftW)
    for i, p in StrSplit(PT){
        result .= (c := Key2Val(oRght, oLeft, p))
        oLeft:=Permute(oLeft, c, 1)
        oRght:=Permute(oRght, p)
    }
    return result
}
;-------------------------------------------
Chao_Decipher(CT, LeftW, RghtW){
    oRght:=StrSplit(RghtW), oLeft:=StrSplit(LeftW)
    for i, c in StrSplit(CT){
        result .= (p := Key2Val(oLeft, oRght, c))
        oLeft:=Permute(oLeft, c, 1)
        oRght:=Permute(oRght, p)
    }    
    return result
}
;-------------------------------------------
Key2Val(Key, Val, char){
    for i, ch in Key
        if (ch = char)
            return Val[i]
}
;-------------------------------------------
Permute(Arr, ch, dt:=0){
    for i, c in Arr
        if (c=ch)
            break
    loop % i-dt
        Arr.Push(Arr.RemoveAt(1))               ; shift left
    ch := Arr[3-dt]                             ; save 2nd/3rd chr
    loop % 11+dt
        Arr[A_Index+2-dt]:=Arr[A_Index+3-dt]    ; shift pos 3/4-14 left
    Arr[14] := ch                               ; place 2nd/3rd chr in pos 14
    return Arr
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#ALGOL_W | 
	ALGOL W | 
	begin
    % print the first 15 Catalan numbers from Pascal's triangle %
    integer n;
    n := 15;
    begin
        integer array pascalLine ( 1 :: n + 1 );
        % the Catalan numbers are the differences between the middle and middle - 1 numbers of the odd %
        % lines of Pascal's triangle (lines with 3 or more numbers)                                    %
        % note - we only need to calculate the left side of the triangle                               %
        pascalLine( 1 ) := 1;
        for c := 2 until n + 1 do begin
            % even line %
            for i := c - 1 step -1 until 2 do pascalLine( i ) := pascalLine( i - 1 ) + pascalLine( i );
            pascalLine( c ) := pascalLine( c - 1 );
            % odd line %
            for i := c     step -1 until 2 do pascalLine( i ) := pascalLine( i - 1 ) + pascalLine( i );
            writeon( i_w := 1, s_w := 0, " ", pascalLine( c ) - pascalLine( c - 1 ) )
        end for_c
    end
end. | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#APL | 
	APL | 
	 
      ⍝ Based heavily on the J solution
      CATALAN←{¯1↓↑-/1 ¯1↓¨(⊂⎕IO+0 0)⍉¨0 2⌽¨⊂(⎕IO-⍨⍳N){+\⍣⍺⊢⍵}⍤0 1⊢1⍴⍨N←⍵+2}
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Action.21 | 
	Action! | 
	PROC Main()
  CHAR ARRAY dog="Bernie"
 
  PrintF("There is just one dog named %S.",dog)
RETURN | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Ada | 
	Ada | 
	with Ada.Text_IO;
procedure Dogs is
   Dog : String := "Bernie";
begin
   Ada.Text_IO.Put_Line ("There is just one dog named " & DOG);
end Dogs; | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#C | 
	C | 
	#include <stdio.h>
#include <string.h>
#include <stdlib.h>
 
#define TRUE 1
#define FALSE 0
 
typedef int bool;
typedef enum { ENCRYPT, DECRYPT } cmode;
 
const char *l_alphabet = "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
const char *r_alphabet = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
 
void chao(const char *in, char *out, cmode mode, bool show_steps) {
    int i, j, index;
    char store;
    size_t len = strlen(in);
    char left[27], right[27], temp[27];
    strcpy(left, l_alphabet);
    strcpy(right, r_alphabet);
    temp[26] = '\0';
 
    for (i = 0; i < len; ++i ) {
        if (show_steps) printf("%s  %s\n", left, right);
        if (mode == ENCRYPT) {
            index = strchr(right, in[i]) - right;
            out[i] = left[index];
        }
        else {
            index = strchr(left, in[i]) - left;
            out[i] = right[index];
        }
        if (i == len - 1) break;
 
        /* permute left */
 
        for (j = index; j < 26; ++j) temp[j - index] = left[j];
        for (j = 0; j < index; ++j) temp[26 - index + j] = left[j];
        store = temp[1];
        for (j = 2; j < 14; ++j) temp[j - 1] = temp[j];
        temp[13] = store;
        strcpy(left, temp);
 
        /* permute right */
 
        for (j = index; j < 26; ++j) temp[j - index] = right[j];
        for (j = 0; j < index; ++j) temp[26 - index + j] = right[j];
        store = temp[0];
        for (j = 1; j < 26; ++j) temp[j - 1] = temp[j];
        temp[25] = store;
        store = temp[2];
        for (j = 3; j < 14; ++j) temp[j - 1] = temp[j];
        temp[13] = store;
        strcpy(right, temp);
    }
}
 
int main() {
    const char *plain_text = "WELLDONEISBETTERTHANWELLSAID";
    char *cipher_text = malloc(strlen(plain_text) + 1);
    char *plain_text2 = malloc(strlen(plain_text) + 1);
    printf("The original plaintext is : %s\n", plain_text);
    printf("\nThe left and right alphabets after each permutation"
           " during encryption are :\n\n");
    chao(plain_text, cipher_text, ENCRYPT, TRUE);
    printf("\nThe ciphertext is : %s\n", cipher_text);
    chao(cipher_text, plain_text2, DECRYPT, FALSE);
    printf("\nThe recovered plaintext is : %s\n", plain_text2);
    free(cipher_text);
    free(plain_text2);
    return 0;
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#AutoHotkey | 
	AutoHotkey | 
	/* Generate Catalan Numbers
//
// smgs: 20th Feb, 2014
*/
Array := [], Array[2,1] := Array[2,2] := 1 ; Array inititated and 2nd row of pascal's triangle assigned
INI := 3 ; starts with calculating the 3rd row and as such the value
Loop, 31 ; every odd row is taken for calculating catalan number as such to obtain 15 we need 2n+1
{
	if ( A_index > 2 )
	{
		Loop, % A_INDEX
		{
			old := ini-1, 		index := A_index, 		index_1 := A_index + 1
			Array[ini, index_1] := Array[old, index] + Array[old, index_1]
			Array[ini, 1] := Array[ini, ini] := 1
			line .= Array[ini, A_index] " "
		}
	;~ MsgBox % line ; gives rows of pascal's triangle
	; calculating every odd row starting from 1st so as to obtain catalan's numbers
		if ( mod(ini,2) != 0)
		{
			StringSplit, res, line, %A_Space%
			ans := res0//2, ans_1 := ans++
			result := result . res%ans_1% - res%ans% " " 
		}
	line :=
	ini++
	}
}
MsgBox % result | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Agena | 
	Agena | 
	scope
    local dog := "Benjamin";
    scope
        local Dog := "Samba";
        scope
            local DOG := "Bernie";
            if DOG <> Dog or DOG <> dog
            then print( "The three dogs are named: " & dog & ", " & Dog & " and " & DOG )
            else print( "There is just one dog named: " & DOG )
            fi
        epocs
    epocs
epocs | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Aime | 
	Aime | 
	text dog, Dog, DOG;
 
dog = "Benjamin";
Dog = "Samba";
DOG = "Bernie";
 
o_form("The three dogs are named ~, ~ and ~.\n", dog, Dog, DOG); | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#C.23 | 
	C# | 
	using System;
 
namespace Chaocipher {
    enum Mode {
        ENCRYPT,
        DECRYPT,
    }
 
    class Program {
        const string L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
        const string R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
 
        static string Exec(string text, Mode mode, bool showSteps = false) {
            char[] left = L_ALPHABET.ToCharArray();
            char[] right = R_ALPHABET.ToCharArray();
            char[] eText = new char[text.Length];
            char[] temp = new char[26];
 
            for (int i = 0; i < text.Length; ++i) {
                if (showSteps) Console.WriteLine("{0} {1}", string.Join("", left), string.Join("", right));
                int index = 0;
                if (mode == Mode.ENCRYPT) {
                    index = Array.IndexOf(right, text[i]);
                    eText[i] = left[index];
                } else {
                    index = Array.IndexOf(left, text[i]);
                    eText[i] = right[index];
                }
                if (i == text.Length - 1) break;
 
                // permute left
 
                for (int j = index; j < 26; ++j) temp[j - index] = left[j];
                for (int j = 0; j < index; ++j) temp[26 - index + j] = left[j];
                var store = temp[1];
                for (int j = 2; j < 14; ++j) temp[j - 1] = temp[j];
                temp[13] = store;
                temp.CopyTo(left, 0);
 
                // permute right
 
                for (int j = index; j < 26; ++j) temp[j - index] = right[j];
                for (int j = 0; j < index; ++j) temp[26 - index + j] = right[j];
                store = temp[0];
                for (int j = 1; j < 26; ++j) temp[j - 1] = temp[j];
                temp[25] = store;
                store = temp[2];
                for (int j = 3; j < 14; ++j) temp[j - 1] = temp[j];
                temp[13] = store;
                temp.CopyTo(right, 0);
            }
 
            return new string(eText);
        }
 
        static void Main(string[] args) {
            var plainText = "WELLDONEISBETTERTHANWELLSAID";
            Console.WriteLine("The original plaintext is : {0}", plainText);
            Console.WriteLine("\nThe left and right alphabets after each permutation during encryption are :\n");
            var cipherText = Exec(plainText, Mode.ENCRYPT, true);
            Console.WriteLine("\nThe ciphertext is : {0}", cipherText);
            var plainText2 = Exec(cipherText, Mode.DECRYPT);
            Console.WriteLine("\nThe recovered plaintext is : {0}", plainText2);
        }
    }
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#AWK | 
	AWK | 
	 
# syntax: GAWK -f CATALAN_NUMBERS_PASCALS_TRIANGLE.AWK
# converted from C
BEGIN {
    printf("1")
    for (n=2; n<=15; n++) {
      num = den = 1
      for (k=2; k<=n; k++) {
        num *= (n + k)
        den *= k
        catalan = num / den
      }
      printf(" %d",catalan)
    }
    printf("\n")
    exit(0)
}
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#ALGOL_68 | 
	ALGOL 68 | 
	#!/usr/bin/a68g --script #
# -*- coding: utf-8 -*- #
 
STRING dog = "Benjamin";
OP D = (INT og)STRING: "Samba"; 
OP DOG = (INT gy)STRING: "Bernie";
INT og=~, gy=~;
 
main:(
  printf(($"The three dogs are named "g", "g" and "g"."l$, dog, Dog, DOGgy));
  0
) | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#ALGOL_W | 
	ALGOL W | 
	begin
    string(8) dog;
    dog := "Benjamin";
    begin
        string(8) Dog;
        Dog := "Samba";
        begin
            string(8) DOG;
            DOG := "Bernie";
            if DOG not = Dog
            or DOG not = dog
            then write( "The three dogs are named: ", dog, ", ", Dog, " and ", DOG )
            else write( "There is just one dog named: ", DOG )
        end
    end
end. | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#C.2B.2B | 
	C++ | 
	#include <iostream>
 
enum class Mode {
    ENCRYPT,
    DECRYPT,
};
 
const std::string L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
const std::string R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
 
std::string exec(std::string text, Mode mode, bool showSteps = false) {
    auto left = L_ALPHABET;
    auto right = R_ALPHABET;
    auto eText = new char[text.size() + 1];
    auto temp = new char[27];
 
    memset(eText, 0, text.size() + 1);
    memset(temp, 0, 27);
 
    for (size_t i = 0; i < text.size(); i++) {
        if (showSteps) std::cout << left << ' ' << right << '\n';
        size_t index;
        if (mode == Mode::ENCRYPT) {
            index = right.find(text[i]);
            eText[i] = left[index];
        } else {
            index = left.find(text[i]);
            eText[i] = right[index];
        }
        if (i == text.size() - 1) break;
 
        // permute left
 
        for (int j = index; j < 26; ++j) temp[j - index] = left[j];
        for (int j = 0; j < index; ++j) temp[26 - index + j] = left[j];
        auto store = temp[1];
        for (int j = 2; j < 14; ++j) temp[j - 1] = temp[j];
        temp[13] = store;
        left = temp;
 
        // permurte right
 
        for (int j = index; j < 26; ++j) temp[j - index] = right[j];
        for (int j = 0; j < index; ++j) temp[26 - index + j] = right[j];
        store = temp[0];
        for (int j = 1; j < 26; ++j) temp[j - 1] = temp[j];
        temp[25] = store;
        store = temp[2];
        for (int j = 3; j < 14; ++j) temp[j - 1] = temp[j];
        temp[13] = store;
        right = temp;
    }
 
    return eText;
}
 
int main() {
    auto plainText = "WELLDONEISBETTERTHANWELLSAID";
    std::cout << "The original plaintext is : " << plainText << "\n\n";
    std::cout << "The left and right alphabets after each permutation during encryption are :\n";
    auto cipherText = exec(plainText, Mode::ENCRYPT, true);
    std::cout << "\nThe ciphertext is : " << cipherText << '\n';
    auto plainText2 = exec(cipherText, Mode::DECRYPT);
    std::cout << "\nThe recovered plaintext is : " << plainText2 << '\n';
 
    return 0;
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#Batch_File | 
	Batch File | 
	@echo off
setlocal ENABLEDELAYEDEXPANSION
set n=15
set /A nn=n+1
for /L %%i in (0,1,%nn%) do set t.%%i=0
set t.1=1
for /L %%i in (1,1,%n%) do (
    set /A ip=%%i+1
    for /L %%j in (%%i,-1,1) do (
        set /A jm=%%j-1
	    set /A t.%%j=t.%%j+t.!jm!
	)
    set /A t.!ip!=t.%%i	  
    for /L %%j in (!ip!,-1,1) do (
        set /A jm=%%j-1
	    set /A t.%%j=t.%%j+t.!jm!
	)
    set /A ci=t.!ip!-t.%%i
	echo !ci!
  )
)
pause | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#APL | 
	APL | 
	      DOG←'Benjamin'
      Dog←'Samba'
      dog←'Bernie'
      'The three dogs are named ',DOG,', ',Dog,', and ',dog
The three dogs are named Benjamin, Samba, and Bernie | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Arturo | 
	Arturo | 
	dog: "Benjamin"
Dog: "Samba"
DOG: "Bernie"
 
dogs: @[dog Dog DOG]
 
print ["The" size dogs "dog(s) are named" join.with:", " dogs] | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#D | 
	D | 
	import std.stdio;
import std.string;
 
immutable L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
immutable R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
 
enum Mode {
    ENCRYPT,
    DECRYPT,
}
 
string exec(string text, Mode mode, bool showSteps = false) {
    char[] left = L_ALPHABET.dup;
    char[] right = R_ALPHABET.dup;
    char[] eText;
    eText.length = text.length;
    char[26] temp;
 
    foreach (i; 0..text.length) {
        if (showSteps) writeln(left, ' ', right);
        int index;
        if (mode == Mode.ENCRYPT) {
            index = right.indexOf(text[i]);
            eText[i] = left[index];
        } else {
            index = left.indexOf(text[i]);
            eText[i] = right[index];
        }
        if (i == text.length - 1) break;
 
        // permute left
 
        foreach (j; index..26) temp[j - index] = left[j];
        foreach (j; 0..index) temp[26 - index + j] = left[j];
        auto store = temp[1];
        foreach (j; 2..14) temp[j - 1] = temp[j];
        temp[13] = store;
        left = temp.dup;
 
        // permute right
 
        foreach (j; index..26) temp[j - index] = right[j];
        foreach (j; 0..index) temp[26 - index + j] = right[j];
        store = temp[0];
        foreach (j; 1..26) temp[j - 1] = temp[j];
        temp[25] = store;
        store = temp[2];
        foreach (j; 3..14) temp[j - 1] = temp[j];
        temp[13] = store;
        right = temp.dup;
    }
 
    return eText.idup;
}
 
void main() {
    auto plainText = "WELLDONEISBETTERTHANWELLSAID";
    writeln("The original plaintext is : ", plainText);
    writeln("\nThe left and right alphabets after each permutation during encryption are :\n");
    auto cipherText = exec(plainText, Mode.ENCRYPT, true);
    writeln("\nThe ciphertext is : ", cipherText);
    auto plainText2 = exec(cipherText, Mode.DECRYPT);
    writeln("\nThe recovered plaintext is : ", plainText2);
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#C | 
	C | 
	 
//This code implements the print of 15 first Catalan's Numbers
//Formula used:
//  __n__
//   | |  (n + k) / k  n>0
//   k=2  
 
#include <stdio.h>
#include <stdlib.h>
 
//the number of Catalan's Numbers to be printed
const int N = 15;
 
int main()
{
    //loop variables (in registers)
    register int k, n;
 
    //necessarily ull for reach big values
    unsigned long long int num, den;
 
    //the nmmber
    int catalan;
 
    //the first is not calculated for the formula
    printf("1 ");
 
    //iterating from 2 to 15
    for (n=2; n<=N; ++n) {
        //initializaing for products
        num = den = 1;
        //applying the formula
        for (k=2; k<=n; ++k) {
            num *= (n+k);
            den *= k;
            catalan = num /den;
        }
 
        //output
        printf("%d ", catalan);
    }
 
    //the end
    printf("\n");
    return 0;
}
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#AutoHotkey | 
	AutoHotkey | 
	dog := "Benjamin"
Dog := "Samba"
DOG := "Bernie"
MsgBox There is just one dog named %dOG% | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#AWK | 
	AWK | 
	BEGIN {
	dog = "Benjamin"
	Dog = "Samba"
	DOG = "Bernie"
	printf "The three dogs are named %s, %s and %s.\n", dog, Dog, DOG
} | 
| 
	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
 | 
	#11l | 
	11l | 
	print((1..3).reduce((x, y) -> x + y))
print((1..3).reduce(3, (x, y) -> x + y))
print([1, 1, 3].reduce((x, y) -> x + y))
print([1, 1, 3].reduce(2, (x, y) -> x + y)) | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Delphi | 
	Delphi | 
	 
program Chaocipher;
 
{$APPTYPE CONSOLE}
 
uses
  System.SysUtils;
 
type
  TMode = (mcEncrypt, mcDecrypt);
 
const
  lAlphabet = 'HXUCZVAMDSLKPEFJRIGTWOBNYQ';
  rAlphabet = 'PTLNBQDEOYSFAVZKGJRIHWXUMC';
 
function Chao(text: AnsiString; Mode: TMode; showSteps: boolean): AnsiString;
begin
  var len := Length(text);
 
  var left: AnsiString := lAlphabet;
  var right: AnsiString := rAlphabet;
 
  var eText: AnsiString;
  SetLength(eText, len);
  var temp: AnsiString;
  SetLength(temp, 26);
 
  for var i := 0 to len - 1 do
  begin
    if showSteps then
      writeln(left, ' ', right);
 
    var index := 0;
 
    if Mode = mcEncrypt then
    begin
      index := pos(text[i + 1], right) - 1;
      eText[i + 1] := left[index + 1];
    end
    else
    begin
      index := pos(text[i + 1], left) - 1;
      eText[i + 1] := right[index + 1];
    end;
 
    if i = len - 1 then
      Break;
 
    // premute left
    for var j := index to 25 do
      temp[j - index + 1] := left[j + 1];
 
    for var j := 0 to index - 1 do
      temp[27 - index + j] := left[j + 1];
    var store := temp[2];
 
    for var j := 2 to 13 do
      temp[j] := temp[j + 1];
 
    temp[14] := store;
 
    left := temp;
 
    // permute right
    for var j := index to 25 do
      temp[j - index + 1] := right[j + 1];
 
    for var j := 0 to index - 1 do
      temp[27 - index + j] := right[j + 1];
 
    store := temp[0 + 1];
 
    for var j := 1 to 25 do
      temp[j] := temp[j + 1];
 
    temp[26] := store;
    store := temp[3];
 
    for var j := 3 to 13 do
      temp[j] := temp[j + 1];
 
    temp[14] := store;
 
    right := temp;
  end;
  Result := eText;
end;
 
begin
  var plainText := 'WELLDONEISBETTERTHANWELLSAID';
  writeln('The original plaintext is :', plainText);
  write(#10'The left and right alphabets after each permutation ');
  writeln('during encryption are :'#10);
  var cipherText := Chao(plainText, mcEncrypt, true);
  writeln(#10'The ciphertext is :', cipherText);
  var plainText2 := Chao(cipherText, mcDecrypt, false);
  writeln(#10'The recovered plaintext is : ', plainText2);
  readln;
end. | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#C.23 | 
	C# | 
	 
int n = 15;
List<int> t = new List<int>() { 0, 1 };
for (int i = 1; i <= n; i++)
{
    for (var j = i; j > 1; j--) t[j] += t[j - 1];
    t.Add(t[i]);
    for (var j = i + 1; j > 1; j--) t[j] += t[j - 1];
    Console.Write(((i == 1) ? "" : ", ") + (t[i + 1] - t[i]));
}
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#BASIC | 
	BASIC | 
	DOG$ = "Benjamin"
DOG$ = "Samba"
DOG$ = "Bernie"
PRINT "There is just one dog, named "; DOG$ | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#BASIC256 | 
	BASIC256 | 
	dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
print "There is just one dog, named "; dog
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
 | 
	#6502_Assembly | 
	6502 Assembly | 
	define catbuf $10
define catbuf_temp $12
 
ldx #0
ramloop:
txa
sta $00,x
inx
cpx #$10
bne ramloop	
;load zero page addresses $00-$0f with values equal
;to that address
 
 
ldx #0		;zero X
loop_cata:
lda $00,x	;load the zeroth element
clc
adc $01,x	;add the first to it.
inx		
inx		;inx twice. Otherwise the same element
		;would get added twice
sta catbuf_temp ;store in temp ram
lda catbuf	
clc
adc catbuf_temp ;add to previously stored value
sta catbuf	;store in result
cpx #$10	;is the range over?
bne loop_cata	;if not, loop again
 
ldx #$00
lda catbuf
sta $00,x	
;store the sum in the zeroth entry of the range
 
inx
lda #$00
 
;now clear the rest of zeropage, leaving only the sum
 
clear_ram:
sta $00,x
inx
cpx #$ff
bne clear_ram | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#F.23 | 
	F# | 
	 
// Implement Chaocipher. Nigel Galloway: July 13th., 2019
let pL n=function g when g=n->0 |g when g=(n+1)%26->13 |g->let x=(25+g-n)%26 in if x<13 then x else x+1
let pR n=function g when g=n->25 |g when g=(n+3)%26->13 |g when g=(n+1)%26->0 |g when g=(n+2)%26->1 |g->let x=(24+g-n)%26 in if x<13 then x else x+1
let encrypt lW rW txt=Array.scan(fun (lW,rW) t->let n=Array.findIndex(fun n->n=t) rW in ((Array.permute(pL n) lW,(Array.permute(pR n) rW))))(lW,rW) txt
                        |>Array.skip 1|>Array.map(fun(n,_)->n.[0])|>System.String
let decrypt lW rW txt=Array.scan(fun (_,lW,rW) t->let n=Array.findIndex(fun n->n=t) lW in ((Array.item n rW,Array.permute(pL n) lW,(Array.permute(pR n) rW))))('0',lW,rW) txt
                        |>Array.skip 1|>Array.map(fun(n,_,_)->n)|>System.String
  | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#C.2B.2B | 
	C++ | 
	// Generate Catalan Numbers
//
// Nigel Galloway: June 9th., 2012
//
#include <iostream>
int main() {
  const int N = 15;
  int t[N+2] = {0,1};
  for(int i = 1; i<=N; i++){
    for(int j = i; j>1; j--) t[j] = t[j] + t[j-1];
    t[i+1] = t[i];
    for(int j = i+1; j>1; j--) t[j] = t[j] + t[j-1];
    std::cout << t[i+1] - t[i] << " ";
  }
  return 0;
} | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Batch_File | 
	Batch File | 
	 
@echo off
 
set dog=Benjamin
set Dog=Samba
set DOG=Bernie
 
echo There is just one dog named %dog%.
pause>nul
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#BBC_BASIC | 
	BBC BASIC | 
	      dog$ = "Benjamin"
      Dog$ = "Samba"
      DOG$ = "Bernie"
      PRINT "The three dogs are " dog$ ", " Dog$ " and " DOG$ "." | 
| 
	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
 | 
	#ABAP | 
	ABAP | 
	 
report z_catamorphism.
 
data(numbers) = value int4_table( ( 1 ) ( 2 ) ( 3 ) ( 4 ) ( 5 ) ).
 
write: |numbers = { reduce string(
  init output = `[`
       index = 1
  for number in numbers
  next output = cond string(
         when index eq lines( numbers )
         then |{ output }, { number } ]|
         when index > 1
         then |{ output }, { number }|
         else |{ output } { number }| )
       index = index + 1 ) }|, /.
 
write: |sum(numbers) = { reduce int4(
  init result = 0
  for number in numbers
  next result = result + number ) }|, /.
 
write: |product(numbers) = { reduce int4(
  init result = 1
  for number in numbers
  next result = result * number ) }|, /.
 
data(strings) = value stringtab( ( `reduce` ) ( `in` ) ( `ABAP` ) ).
 
write: |strings = { reduce string(
  init output = `[`
       index = 1
  for string in strings
  next output = cond string(
         when index eq lines( strings )
         then |{ output }, { string } ]|
         when index > 1
         then |{ output }, { string }|
         else |{ output } { string }| )
       index = index + 1 ) }|, /.
 
write: |concatenation(strings) = { reduce string(
  init text = ``
  for string in strings
  next text = |{ text } { string }| ) }|, /.
  | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Factor | 
	Factor | 
	USING: arrays combinators fry io kernel locals math namespaces
prettyprint sequences sequences.extras strings ;
IN: rosetta-code.chaocipher
 
CONSTANT: zenith 0
CONSTANT: nadir  13
 
SYMBOLS: l-alphabet r-alphabet last-index ;
 
: init-alphabets ( -- )
    "HXUCZVAMDSLKPEFJRIGTWOBNYQ" l-alphabet
    "PTLNBQDEOYSFAVZKGJRIHWXUMC" r-alphabet [ set ] 2bi@ ;
 
: zero-alphabet ( seq -- seq' )
    last-index get rotate ;
 
: 3append ( a b c d -- abcd )
    append append append ;
 
:: permute-l-alphabet ( -- )
    l-alphabet get zero-alphabet dup
    zenith 1 + swap nth :> extracted-char
    {
        [ 1 head ]
        [ nadir 1 + head 2 tail ]
        [ drop extracted-char 1string ]
        [ nadir 1 + tail ]
    } cleave
    3append l-alphabet set ;
 
:: permute-r-alphabet ( -- )
    r-alphabet get zero-alphabet
    1 rotate dup
    zenith 2 + swap nth :> extracted-char
    {
        [ 2 head ]
        [ nadir 1 + head 3 tail ]
        [ drop extracted-char 1string ]
        [ nadir 1 + tail ]
    } cleave
    3append r-alphabet set ;
 
: encipher-char ( char alpha1 alpha2 -- char' )
    '[ _ get index dup last-index set _ get nth ] call ;
 
: encipher ( str quot -- str' )
    [ permute-l-alphabet permute-r-alphabet ] compose map
    init-alphabets ; inline
 
: encrypt ( str -- str' )
    [ r-alphabet l-alphabet encipher-char ] encipher ;
 
: decrypt ( str -- str' )
    [ l-alphabet r-alphabet encipher-char ] encipher ;
 
: main ( -- )
    init-alphabets
    "WELLDONEISBETTERTHANWELLSAID" encrypt dup decrypt
    [ print ] bi@ ;
 
MAIN: main | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#Common_Lisp | 
	Common Lisp | 
	(defun catalan (n)
  "Return the n-th Catalan number"
  (if (<= n 1)  1
    (let ((result 2))
      (dotimes (k (- n 2) result)
        (setq result (* result (/ (+ n k 2) (+ k 2)))) ))))
 
 
(dotimes (n 15)
  (print (catalan (1+ n))) ) | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#bc | 
	bc | 
	obase = 16
ibase = 16
 
/*
 * Store the hexadecimal number 'BE27A312'
 * in the variable 'd'.
 */
d = BE27A312
"There is just one dog named "; d
quit | 
| 
	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
 | 
	#Ada | 
	Ada | 
	with Ada.Text_IO;
 
procedure Catamorphism is
 
   type Fun is access function (Left, Right: Natural) return Natural;
   type Arr is array(Natural range <>) of Natural;
 
   function Fold_Left (F: Fun; A: Arr) return Natural is
      Result: Natural := A(A'First);
   begin
      for I in A'First+1 .. A'Last loop
	 Result := F(Result, A(I));
      end loop;
      return Result;
   end Fold_Left;
 
   function Max (L, R: Natural) return Natural is (if L > R then L else R);
   function Min (L, R: Natural) return Natural is (if L < R then L else R);     
   function Add (Left, Right: Natural) return Natural is (Left + Right);
   function Mul (Left, Right: Natural) return Natural is (Left * Right);
 
   package NIO is new Ada.Text_IO.Integer_IO(Natural);   
 
begin
   NIO.Put(Fold_Left(Min'Access, (1,2,3,4)), Width => 3);
   NIO.Put(Fold_Left(Max'Access, (1,2,3,4)), Width => 3);
   NIO.Put(Fold_Left(Add'Access, (1,2,3,4)), Width => 3);
   NIO.Put(Fold_Left(Mul'Access, (1,2,3,4)), Width => 3);
end Catamorphism; | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#F.C5.8Drmul.C3.A6 | 
	Fōrmulæ | 
	package main
 
import(
    "fmt"
    "strings"
    "unicode/utf8"
)
 
type Mode int
 
const(
    Encrypt Mode = iota
    Decrypt
)
 
const(
    lAlphabet = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
    rAlphabet = "PTLNBQDEOYSFAVZKGJRIHWXUMC"
)
 
func Chao(text string, mode Mode, showSteps bool) string {
    len := len(text)
    if utf8.RuneCountInString(text) != len {
        fmt.Println("Text contains non-ASCII characters")
        return ""
    }
    left  := lAlphabet
    right := rAlphabet
    eText := make([]byte, len)
    temp  := make([]byte, 26)
 
    for i := 0; i < len; i++ {
        if showSteps {
            fmt.Println(left, " ", right)
        }
        var index int
        if mode == Encrypt {
            index = strings.IndexByte(right, text[i])
            eText[i] = left[index]
        } else {
            index = strings.IndexByte(left, text[i])
            eText[i] = right[index]
        }
        if i == len - 1 {
            break
        }
 
        // permute left
        for j := index; j < 26; j++ {
            temp[j - index] = left[j]
        }
        for j := 0; j < index; j++ {
            temp[26 - index + j] = left[j]
        }
        store := temp[1]
        for j := 2; j < 14; j++ {
            temp[j - 1] = temp[j]
        }
        temp[13] = store
        left = string(temp[:])
 
        // permute right
 
        for j := index; j < 26; j++ {
            temp[j - index] = right[j]
        }
        for j := 0; j < index; j++ {
            temp[26 - index + j] = right[j]
        }
        store = temp[0]
        for j := 1; j < 26; j++ {
            temp[j - 1] = temp[j]
        }
        temp[25] = store
        store = temp[2]
        for j := 3; j < 14; j++ {
            temp[j - 1] = temp[j]
        }
        temp[13] = store
        right = string(temp[:])
    }
 
    return string(eText[:])
}
 
func main() {
    plainText := "WELLDONEISBETTERTHANWELLSAID"
    fmt.Println("The original plaintext is :", plainText)
    fmt.Print("\nThe left and right alphabets after each permutation ")
    fmt.Println("during encryption are :\n")
    cipherText := Chao(plainText, Encrypt, true)
    fmt.Println("\nThe ciphertext is :",  cipherText)
    plainText2 := Chao(cipherText, Decrypt, false)
    fmt.Println("\nThe recovered plaintext is :", plainText2)
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#D | 
	D | 
	void main() {
    import std.stdio;
 
    enum uint N = 15;
    uint[N + 2] t;
    t[1] = 1;
 
    foreach (immutable i; 1 .. N + 1) {
        foreach_reverse (immutable j; 2 .. i + 1)
            t[j] += t[j - 1];
        t[i + 1] = t[i];
        foreach_reverse (immutable j; 2 .. i + 2)
            t[j] += t[j - 1];
        write(t[i + 1] - t[i], ' ');
    }
} | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Bracmat | 
	Bracmat | 
	( Benjamin:?dog
& Samba:?Dog
& Bernie:?DOG
& out$("There are three dogs:" !dog !Dog and !DOG)
); | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Brlcad | 
	Brlcad | 
	 
opendb dogs.g y            # Create a database to hold our dogs
units ft                   # The dogs are measured in feet
in dog.s sph 0 0 0 1       # Benjie is a little Scottie dog
in Dog.s sph 4 0 0 3       # Samba is a Labrador
in DOG.s sph 13 0 0 5      # Bernie is massive. He is a New Foundland
echo The three dogs are named Benjamin, Samba and Bernie | 
| 
	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
 | 
	#Aime | 
	Aime | 
	integer s;
 
s = 0;
list(1, 2, 3, 4, 5, 6, 7, 8, 9).ucall(add_i, 1, s);
o_(s, "\n"); | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Go | 
	Go | 
	package main
 
import(
    "fmt"
    "strings"
    "unicode/utf8"
)
 
type Mode int
 
const(
    Encrypt Mode = iota
    Decrypt
)
 
const(
    lAlphabet = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
    rAlphabet = "PTLNBQDEOYSFAVZKGJRIHWXUMC"
)
 
func Chao(text string, mode Mode, showSteps bool) string {
    len := len(text)
    if utf8.RuneCountInString(text) != len {
        fmt.Println("Text contains non-ASCII characters")
        return ""
    }
    left  := lAlphabet
    right := rAlphabet
    eText := make([]byte, len)
    temp  := make([]byte, 26)
 
    for i := 0; i < len; i++ {
        if showSteps {
            fmt.Println(left, " ", right)
        }
        var index int
        if mode == Encrypt {
            index = strings.IndexByte(right, text[i])
            eText[i] = left[index]
        } else {
            index = strings.IndexByte(left, text[i])
            eText[i] = right[index]
        }
        if i == len - 1 {
            break
        }
 
        // permute left
        for j := index; j < 26; j++ {
            temp[j - index] = left[j]
        }
        for j := 0; j < index; j++ {
            temp[26 - index + j] = left[j]
        }
        store := temp[1]
        for j := 2; j < 14; j++ {
            temp[j - 1] = temp[j]
        }
        temp[13] = store
        left = string(temp[:])
 
        // permute right
 
        for j := index; j < 26; j++ {
            temp[j - index] = right[j]
        }
        for j := 0; j < index; j++ {
            temp[26 - index + j] = right[j]
        }
        store = temp[0]
        for j := 1; j < 26; j++ {
            temp[j - 1] = temp[j]
        }
        temp[25] = store
        store = temp[2]
        for j := 3; j < 14; j++ {
            temp[j - 1] = temp[j]
        }
        temp[13] = store
        right = string(temp[:])
    }
 
    return string(eText[:])
}
 
func main() {
    plainText := "WELLDONEISBETTERTHANWELLSAID"
    fmt.Println("The original plaintext is :", plainText)
    fmt.Print("\nThe left and right alphabets after each permutation ")
    fmt.Println("during encryption are :\n")
    cipherText := Chao(plainText, Encrypt, true)
    fmt.Println("\nThe ciphertext is :",  cipherText)
    plainText2 := Chao(cipherText, Decrypt, false)
    fmt.Println("\nThe recovered plaintext is :", plainText2)
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#Delphi | 
	Delphi | 
	 
(define dim 100)
(define-syntax-rule  (Tidx i j)  (+ i (* dim j)))
 
;; generates Catalan's triangle
;; T (i , j) = T(i-1,j) + T (i, j-1)
 
(define (T n)
	(define i (modulo n dim))
	(define j (quotient n dim))
	(cond 
		((zero? i) 1) ;; left column = 1
		((= i j) (T (Tidx (1- i) j))) ;; diagonal value = left value
		(else (+ (T (Tidx (1- i) j)) (T (Tidx i (1- j)))))))
 
(remember 'T #(1))
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#C | 
	C | 
	#include <stdio.h>
 
static const char *dog = "Benjamin";
static const char *Dog = "Samba";
static const char *DOG = "Bernie";
 
int main()
{
    printf("The three dogs are named %s, %s and %s.\n", dog, Dog, DOG);
    return 0;
} | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#C.23 | 
	C# | 
	 
using System;
 
class Program
{
    static void Main(string[] args)
    {
        string dog = "Benjamin";
        string Dog = "Samba";
        string DOG = "Bernie";
        Console.WriteLine(string.Format("The three dogs are named {0}, {1}, and {2}.", dog, Dog, DOG));
    }
} | 
| 
	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
 | 
	#ALGOL_68 | 
	ALGOL 68 | 
	# applies fn to successive elements of the array of values #
# the result is 0 if there are no values                   #
PROC reduce = ( []INT values, PROC( INT, INT )INT fn )INT:
     IF UPB values < LWB values
     THEN # no elements #
          0
     ELSE # there are some elements #
          INT result := values[ LWB values ];
          FOR pos FROM LWB values + 1 TO UPB values
          DO
              result := fn( result, values[ pos ] )
          OD;
          result
     FI; # reduce #
 
# test the reduce procedure #
BEGIN print( ( reduce( ( 1, 2, 3, 4, 5 ), ( INT a, b )INT: a + b ), newline ) ) # sum #
    ; print( ( reduce( ( 1, 2, 3, 4, 5 ), ( INT a, b )INT: a * b ), newline ) ) # product #
    ; print( ( reduce( ( 1, 2, 3, 4, 5 ), ( INT a, b )INT: a - b ), newline ) ) # difference #
END | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Groovy | 
	Groovy | 
	class Chaocipher {
    private enum Mode {
        ENCRYPT,
        DECRYPT
    }
 
    private static final String L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
    private static final String R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC"
 
    private static int indexOf(char[] a, char c) {
        for (int i = 0; i < a.length; ++i) {
            if (a[i] == c) {
                return i
            }
        }
        return -1
    }
 
    private static String exec(String text, Mode mode) {
        return exec(text, mode, false)
    }
 
    private static String exec(String text, Mode mode, Boolean showSteps) {
        char[] left = L_ALPHABET.toCharArray()
        char[] right = R_ALPHABET.toCharArray()
        char[] eText = new char[text.length()]
        char[] temp = new char[26]
 
        for (int i = 0; i < text.length(); ++i) {
            if (showSteps) {
                println("${new String(left)}  ${new String(right)}")
            }
            int index
            if (mode == Mode.ENCRYPT) {
                index = indexOf(right, text.charAt(i))
                eText[i] = left[index]
            } else {
                index = indexOf(left, text.charAt(i))
                eText[i] = right[index]
            }
            if (i == text.length() - 1) {
                break
            }
 
            // permute left
 
            if (26 - index >= 0) System.arraycopy(left, index, temp, 0, 26 - index)
            System.arraycopy(left, 0, temp, 26 - index, index)
            char store = temp[1]
            System.arraycopy(temp, 2, temp, 1, 12)
            temp[13] = store
            left = Arrays.copyOf(temp, temp.length)
 
            // permute right
 
            if (26 - index >= 0) System.arraycopy(right, index, temp, 0, 26 - index)
            System.arraycopy(right, 0, temp, 26 - index, index)
            store = temp[0]
            System.arraycopy(temp, 1, temp, 0, 25)
            temp[25] = store
            store = temp[2]
            System.arraycopy(temp, 3, temp, 2, 11)
            temp[13] = store
            right = Arrays.copyOf(temp, temp.length)
        }
 
        return new String(eText)
    }
 
    static void main(String[] args) {
        String plainText = "WELLDONEISBETTERTHANWELLSAID"
        println("The original plaintext is : $plainText")
        println("\nThe left and right alphabets after each permutation during encryption are:")
        String cipherText = exec(plainText, Mode.ENCRYPT, true)
        println("\nThe cipher text is : $cipherText")
        String plainText2 = exec(cipherText, Mode.DECRYPT)
        println("\nThe recovered plaintext is : $plainText2")
    }
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#EchoLisp | 
	EchoLisp | 
	 
(define dim 100)
(define-syntax-rule  (Tidx i j)  (+ i (* dim j)))
 
;; generates Catalan's triangle
;; T (i , j) = T(i-1,j) + T (i, j-1)
 
(define (T n)
	(define i (modulo n dim))
	(define j (quotient n dim))
	(cond 
		((zero? i) 1) ;; left column = 1
		((= i j) (T (Tidx (1- i) j))) ;; diagonal value = left value
		(else (+ (T (Tidx (1- i) j)) (T (Tidx i (1- j)))))))
 
(remember 'T #(1))
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#C.2B.2B | 
	C++ | 
	#include <iostream>
#include <string>
using namespace std;
 
int main() {
    string dog = "Benjamin", Dog = "Samba", DOG = "Bernie";
 
    cout << "The three dogs are named " << dog << ", " << Dog << ", and " << DOG << endl;
} | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Clojure | 
	Clojure | 
	user=> (let [dog "Benjamin" Dog "Samba" DOG "Bernie"] (format "The three dogs are named %s, %s and %s." dog Dog DOG))
"The three dogs are named Benjamin, Samba and Bernie." | 
| 
	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}
 | 
	#11l | 
	11l | 
	F cart_prod(a, b)
   V p = [(0, 0)] * (a.len * b.len)
   V i = 0
   L(aa) a
      L(bb) b
         p[i++] = (aa, bb)
   R p
 
print(cart_prod([1, 2], [3, 4]))
print(cart_prod([3, 4], [1, 2]))
[Int] empty_array
print(cart_prod([1, 2], empty_array))
print(cart_prod(empty_array, [1, 2])) | 
| 
	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
 | 
	#APL | 
	APL | 
	      +/ 1 2 3 4 5 6 7
28
      ×/ 1 2 3 4 5 6 7
5040 | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Haskell | 
	Haskell | 
	import Data.List (elemIndex)
 
chao :: Eq a => [a] -> [a] -> Bool -> [a] -> [a]
chao _ _ _ [] = []
chao l r plain (x : xs) = maybe [] go (elemIndex x src)
  where
    (src, dst)
      | plain = (l, r)
      | otherwise = (r, l)
    go n =
      dst !! n :
      chao
        (shifted 1 14 (rotated n l))
        ((shifted 2 14 . shifted 0 26) (rotated n r))
        plain
        xs
 
rotated :: Int -> [a] -> [a]
rotated n = take . length <*> drop n . cycle
 
shifted :: Int -> Int -> [a] -> [a]
shifted src dst s = concat [x, rotated 1 y, b]
  where
    (a, b) = splitAt dst s
    (x, y) = splitAt src a
 
encode, decode :: Bool
encode = False
decode = True
 
main :: IO ()
main = do
  let chaoWheels =
        chao
          "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
          "PTLNBQDEOYSFAVZKGJRIHWXUMC"
      plainText = "WELLDONEISBETTERTHANWELLSAID"
      cipherText = chaoWheels encode plainText
  mapM_
    print
    [ plainText,
      cipherText,
      chaoWheels decode cipherText
    ] | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#EDSAC_order_code | 
	EDSAC order code | 
	 
 [Catalan numbers from Pascal triangle, Rosetta Code website.
  EDSAC program, Initial Orders 2]
            ..PZ  [blank tape and terminator]
            T54K  [refer to working array with 'C']
            P300F [address of working array]
            T46K  [to call print subroutine with 'G N']
            P56F  [address of print subroutine]
 
 [Modification of library subroutine P7.
  Prints non-negative integer, up to 10 digits, right-justified.
  55 locations, load at even address.]
           E25KTN
  GKA3FT42@A47@T31@ADE10@T31@A48@T31@SDTDH44#@NDYFLDT4DS43@
  TFH17@S17@A43@G23@UFS43@T1FV4DAFG50@SFLDUFXFOFFFSFL4FT4DA49@
  T31@A1FA43@G20@XFP1024FP610D@524D!FO46@O26@XFO46@SFL8FT4DE39@
 
 [Main program]
            PK  T200K GK
        [Constants]
      [0]   PD   [short constant 1]
      [1]   P2F  [to inc address by 2]
      [2]   T#C  [used in manufacturing EDSAC orders]
      [3]   MF   [add to T order to make A order with same address]
      [4]   #F   [set figures]
      [5]   &F   [line feed]
      [6]   @F   [carriage return]
      [7]   P7D  [maximum n = 15]
        [Variable]
      [8]   PF   [n]
        [Enter with acc = 0]
      [9]   O4@                      [set teleprinter to figures]
            T4#C  T2#C  T#C  A@  TC  [initialize first 3 terms to 1, 0, 0]
            T8@  E58@                [set n := 0; jump to inc n and print C_n]
        [Outer loop; here with n updated]
     [17]   TF  A8@                  [acc := latest n]
            L1F  A2@  T22@           [make and store order 'T 2n #C']
     [22]   T#C                      [sets term := 0; also used to test for end of loop]
            A2@                      [load 'T#C', initial value of order 31]
        [Loop to convert e.g. (20, 15, 6, 1) to (35, 21, 7, 1); works left to right]
     [24]   U31@  A3@  U29@  A1@  T30@  [set up orders on next line]
     [29]   A#C  A#C  T#C            [replaced by manufactured orders]
            A31@  A1@  S22@  E38@    [inc address in order 31, jump out if done]
            A22@  E24@               [not done, loop back]
     [38]   A22@  T48@               [initialize order 48]
        [Loop to convert e.g. (35, 21, 7, 1) to (70, 56, 28, 8, 1); works right to left]
     [40]   TF A48@  A3@  U46@  S1@  T47@  [set up orders on next line]
     [46]   A#C  A#C  T#C            [replaced by manufactured orders]
            A48@  S1@  T48@          [dec address in order 48]
            A2@  S48@  G40@          [test for done, loop back if not]
            A#C  LD  T#C             [double first term, e.g. 35 -> 70 (not done in loop)]
        [Increment n and print Catalan number C_n]
     [58]   TD                       [clear 0D, ensures sandwich bit = 0]
            A8@  A@  U8@  TF         [inc n; set 0D := n by setting 0F := n]
            A63@  GN                 [print n]
            A#C  S4#C  TD  A68@  GN  [print Catalan number C_n, e.g. C_5 = 70 - 28 = 42]
            O6@  O5@                 [print CR, LF]
            A8@  S7@  G17@           [test for maximum n, loop back if not]
     [75]   O4@  ZF                  [flush printer buffer; stop]
            E9Z  PF                  [define entry point; enter with acc = 0]
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#COBOL | 
	COBOL | 
	* Case sensitivity of identifiers
       *>* Commented-out lines in the working storage
       *>* are considered as invalid redefinitions
       *>* of ''dog'' that can only be ambiguously
       *>* referenced in the procedure body.
 
       IDENTIFICATION DIVISION.
       PROGRAM-ID. case-sensitivity.
       DATA DIVISION.
       WORKING-STORAGE SECTION.
       *>* 01  dog PICTURE X(8) VALUE IS "Benjamin".
       *>* 01  Dog PICTURE X(5) VALUE IS "Samba".
       01  DOG PICTURE X(6) VALUE IS "Bernie".
       PROCEDURE DIVISION.
         DISPLAY
       *>*     "The three dogs are named "
       *>*     dog ", " Dog " and " DOG "."
           "There is just one dog named " DOG "."
         END-DISPLAY
         STOP RUN.
       END PROGRAM case-sensitivity. | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#CoffeeScript | 
	CoffeeScript | 
	 
dog="Benjamin"
Dog = "Samba"
DOG = "Bernie"
console.log "The three dogs are names #{dog}, #{Dog}, and #{DOG}."
  | 
| 
	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}
 | 
	#Action.21 | 
	Action! | 
	DEFINE MAX_COUNT="10"
DEFINE MAX_RESULT="100"
 
DEFINE PTR="CARD"
 
PROC PrintInput(PTR ARRAY a INT count)
  INT i,j,n
  INT ARRAY tmp
 
  FOR i=0 TO count-1
  DO
    tmp=a(i) n=tmp(0)
    Put('[)
    FOR j=1 TO n
    DO
      PrintI(tmp(j))
      IF j<n THEN Put(',) FI
    OD
    Put('])
    IF i<count-1 THEN Put('x) FI
  OD
RETURN
 
PROC PrintOutput(INT ARRAY a INT groups,count)
  INT i,j,k
 
  Put('[)
  k=0
  FOR i=0 TO groups-1
  DO
    Put('()
    FOR j=0 TO count-1
    DO
      PrintI(a(k)) k==+1
      IF j<count-1 THEN Put(',) FI
    OD
    Put('))
    IF i<groups-1 THEN Put(',) FI
  OD
  Put('])
RETURN
 
PROC Product(PTR ARRAY a INT count
  INT ARRAY r INT POINTER groups)
  INT ARRAY ind(MAX_COUNT),tmp
  INT i,j,k
 
  IF count>MAX_COUNT THEN Break() FI
  groups^=1
  FOR i=0 TO count-1
  DO
    ind(i)=1 tmp=a(i)
    groups^==*tmp(0)
  OD
  IF groups^=0 THEN RETURN FI
 
  j=count-1 k=0
  DO
    FOR i=0 TO count-1
    DO
      tmp=a(i)
      r(k)=tmp(ind(i)) k==+1
    OD
 
    DO
      tmp=a(j)
      IF ind(j)<tmp(0) THEN
        ind(j)==+1
        FOR i=j+1 TO count-1
        DO
          ind(i)=1
        OD
        j=count-1
        EXIT
      ELSE
        IF j=0 THEN RETURN FI
        j==-1
      FI
    OD
  OD
RETURN
 
PROC Test(PTR ARRAY a INT count)
  INT ARRAY r(MAX_RESULT)
  INT groups
 
  IF count<2 THEN Break() FI
  Product(a,count,r,@groups)
  PrintInput(a,count)
  Put('=)
  PrintOutput(r,groups,count)
  PutE()
RETURN
 
PROC Main()
  INT ARRAY
    a1=[2 1 2],a2=[2 3 4],a3=[0],
    a4=[2 1776 1789],a5=[2 7 12],
    a6=[3 4 14 23],a7=[2 0 1],
    a8=[3 1 2 3],a9=[1 30],a10=[2 500 100]
  PTR ARRAY a(4)
 
  a(0)=a1 a(1)=a2 Test(a,2)
  a(0)=a2 a(1)=a1 Test(a,2)
  a(0)=a1 a(1)=a3 Test(a,2)
  a(0)=a3 a(1)=a1 Test(a,2) PutE()
  a(0)=a4 a(1)=a5 a(2)=a6 a(3)=a7 Test(a,4) PutE()
  a(0)=a8 a(1)=a9 a(2)=a10 Test(a,3) PutE()
  a(0)=a8 a(1)=a3 a(2)=a10 Test(a,3)
RETURN | 
| 
	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
 | 
	#AppleScript | 
	AppleScript | 
	---------------------- CATAMORPHISMS ---------------------
 
-- the arguments available to the called function f(a, x, i, l) are
-- a: current accumulator value
-- x: current item in list
-- i: [ 1-based index in list ] optional
-- l: [ a reference to the list itself ] optional
 
-- foldl :: (a -> b -> a) -> a -> [b] -> a
on foldl(f, startValue, xs)
    tell mReturn(f)
        set v to startValue
        set lng to length of xs
        repeat with i from 1 to lng
            set v to |λ|(v, item i of xs, i, xs)
        end repeat
        return v
    end tell
end foldl
 
-- the arguments available to the called function f(a, x, i, l) are
-- a: current accumulator value
-- x: current item in list
-- i: [ 1-based index in list ] optional
-- l: [ a reference to the list itself ] optional
 
-- foldr :: (a -> b -> a) -> a -> [b] -> a
on foldr(f, startValue, xs)
    tell mReturn(f)
        set v to startValue
        set lng to length of xs
        repeat with i from lng to 1 by -1
            set v to |λ|(v, item i of xs, i, xs)
        end repeat
        return v
    end tell
end foldr
 
 
--- OTHER FUNCTIONS DEFINED IN TERMS OF FOLDL AND FOLDR --
 
-- concat :: [String] -> string
on concat(xs)
    foldl(my append, "", xs)
end concat
 
 
-- product :: Num a => [a] -> a
on product(xs)
    script
        on |λ|(a, b)
            a * b
        end |λ|
    end script
 
    foldr(result, 1, xs)
end product
 
 
-- str :: a -> String
on str(x)
    x as string
end str
 
 
-- sum :: Num a => [a] -> a
on sum(xs)
    script
        on |λ|(a, b)
            a + b
        end |λ|
    end script
 
    foldl(result, 0, xs)
end sum
 
 
--------------------------- TEST -------------------------
on run
    set xs to {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
 
    {sum(xs), product(xs), concat(map(str, xs))}
 
    --> {55, 3628800, "10987654321"}
end run
 
 
-------------------- GENERIC FUNCTIONS -------------------
 
-- append :: String -> String -> String
on append(a, b)
    a & b
end append
 
 
-- map :: (a -> b) -> [a] -> [b]
on map(f, xs)
    -- The list obtained by applying f
    -- to each element of xs.
    tell mReturn(f)
        set lng to length of xs
        set lst to {}
        repeat with i from 1 to lng
            set end of lst to |λ|(item i of xs, i, xs)
        end repeat
        return lst
    end tell
end map
 
 
-- Lift 2nd class handler function into 1st class script wrapper 
-- mReturn :: Handler -> Script
on mReturn(f)
    if class of f is script then
        f
    else
        script
            property |λ| : f
        end script
    end if
end mReturn | 
| 
	http://rosettacode.org/wiki/Chaocipher | 
	Chaocipher | 
	Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
Task
Code the algorithm in your language and to test that it works with the plaintext 'WELLDONEISBETTERTHANWELLSAID' used in the paper itself.
 | 
	#Java | 
	Java | 
	import java.util.Arrays;
 
public class Chaocipher {
    private enum Mode {
        ENCRYPT,
        DECRYPT
    }
 
    private static final String L_ALPHABET = "HXUCZVAMDSLKPEFJRIGTWOBNYQ";
    private static final String R_ALPHABET = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
 
    private static int indexOf(char[] a, char c) {
        for (int i = 0; i < a.length; ++i) {
            if (a[i] == c) {
                return i;
            }
        }
        return -1;
    }
 
    private static String exec(String text, Mode mode) {
        return exec(text, mode, false);
    }
 
    private static String exec(String text, Mode mode, Boolean showSteps) {
        char[] left = L_ALPHABET.toCharArray();
        char[] right = R_ALPHABET.toCharArray();
        char[] eText = new char[text.length()];
        char[] temp = new char[26];
 
        for (int i = 0; i < text.length(); ++i) {
            if (showSteps) {
                System.out.printf("%s  %s\n", new String(left), new String(right));
            }
            int index;
            if (mode == Mode.ENCRYPT) {
                index = indexOf(right, text.charAt(i));
                eText[i] = left[index];
            } else {
                index = indexOf(left, text.charAt(i));
                eText[i] = right[index];
            }
            if (i == text.length() - 1) {
                break;
            }
 
            // permute left
 
            if (26 - index >= 0) System.arraycopy(left, index, temp, 0, 26 - index);
            System.arraycopy(left, 0, temp, 26 - index, index);
            char store = temp[1];
            System.arraycopy(temp, 2, temp, 1, 12);
            temp[13] = store;
            left = Arrays.copyOf(temp, temp.length);
 
            // permute right
 
            if (26 - index >= 0) System.arraycopy(right, index, temp, 0, 26 - index);
            System.arraycopy(right, 0, temp, 26 - index, index);
            store = temp[0];
            System.arraycopy(temp, 1, temp, 0, 25);
            temp[25] = store;
            store = temp[2];
            System.arraycopy(temp, 3, temp, 2, 11);
            temp[13] = store;
            right = Arrays.copyOf(temp, temp.length);
        }
 
        return new String(eText);
    }
 
    public static void main(String[] args) {
        String plainText = "WELLDONEISBETTERTHANWELLSAID";
        System.out.printf("The original plaintext is : %s\n", plainText);
        System.out.println("\nThe left and right alphabets after each permutation during encryption are:");
        String cipherText = exec(plainText, Mode.ENCRYPT, true);
        System.out.printf("\nThe cipher text is : %s\n", cipherText);
        String plainText2 = exec(cipherText, Mode.DECRYPT);
        System.out.printf("\nThe recovered plaintext is : %s\n", plainText2);
    }
} | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#Elixir | 
	Elixir | 
	defmodule Catalan do
  def numbers(num) do
    {result,_} = Enum.reduce(1..num, {[],{0,1}}, fn i,{list,t0} ->
      t1 = numbers(i, t0)
      t2 = numbers(i+1, Tuple.insert_at(t1, i+1, elem(t1, i)))
      {[elem(t2, i+1) - elem(t2, i) | list], t2}
    end)
    Enum.reverse(result)
  end
 
  defp numbers(0, t), do: t
  defp numbers(n, t), do: numbers(n-1, put_elem(t, n, elem(t, n-1) + elem(t, n)))
end
 
IO.inspect Catalan.numbers(15) | 
| 
	http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | 
	Catalan numbers/Pascal's triangle | 
	Task
Print out the first   15   Catalan numbers by extracting them from Pascal's triangle.
See
   Catalan Numbers and the Pascal Triangle.     This method enables calculation of Catalan Numbers using only addition and subtraction.
   Catalan's Triangle for a Number Triangle that generates Catalan Numbers using only addition.
   Sequence A000108 on OEIS has a lot of information on Catalan Numbers.
Related Tasks
Pascal's triangle
 | 
	#Erlang | 
	Erlang | 
	 
-module(catalin).
-compile(export_all).
mul(N,D,S,S)-> 
	N2=N*(S+S),
	D2=D*S,
	K = N2 div D2 ;
mul(N,D,S,L)->
	N2=N*(S+L),
	D2=D*L,
	K = mul(N2,D2,S,L+1).
 
catl(Ans,16) -> Ans;
catl(D,S)->
	C=mul(1,1,S,2),
	catl([D|C],S+1).
main()->
	Ans=catl(1,2).
  | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Common_Lisp | 
	Common Lisp | 
	CL-USER> (let* ((dog "Benjamin") (Dog "Samba") (DOG "Bernie"))
	   (format nil "There is just one dog named ~a." dog))
; in: LAMBDA NIL
;     (LET* ((DOG "Benjamin") (DOG "Samba") (DOG "Bernie"))
;       (FORMAT NIL "There is just one dog named ~a." DOG))
; 
; caught STYLE-WARNING:
;   The variable DOG is defined but never used.
; 
; caught STYLE-WARNING:
;   The variable DOG is defined but never used.
; 
; compilation unit finished
;   caught 2 STYLE-WARNING conditions
"There is just one dog named Bernie." | 
| 
	http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | 
	Case-sensitivity of identifiers | 
	Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language that is lettercase insensitive, we get the following output:
There is just one dog named Bernie.
Related task
 Unicode variable names
 | 
	#Crystal | 
	Crystal | 
	dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
 
puts "The three dogs are named #{dog}, #{Dog} and #{DOG}." | 
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