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http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#D
D
import core.stdc.stdio, std.math, std.typecons, std.string, std.conv, std.algorithm, std.ascii, std.array, bitmap, grayscale_image;   enum maxBrightness = 255;   alias Pixel = short; alias IntT = typeof(size_t.init.signed);   // If normalize is true, map pixels to range 0...maxBrightness. void convolution(bool n...
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#C.2B.2B
C++
#include <cstdint> #include <iomanip> #include <iostream> #include <sstream>   // Class representing an IPv4 address + netmask length class ipv4_cidr { public: ipv4_cidr() {} ipv4_cidr(std::uint32_t address, unsigned int mask_length) : address_(address), mask_length_(mask_length) {} std::uint32_t ad...
http://rosettacode.org/wiki/Casting_out_nines
Casting out nines
Task   (in three parts) Part 1 Write a procedure (say c o 9 ( x ) {\displaystyle {\mathit {co9}}(x)} ) which implements Casting Out Nines as described by returning the checksum for x {\displaystyle x} . Demonstrate the procedure using the examples given there, or others you may consider lucky. Par...
#D
D
import std.stdio, std.algorithm, std.range;   uint[] castOut(in uint base=10, in uint start=1, in uint end=999999) { auto ran = iota(base - 1) .filter!(x => x % (base - 1) == (x * x) % (base - 1)); auto x = start / (base - 1); immutable y = start % (base - 1);   typeof(return) result; ...
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
Catmull–Clark subdivision surface
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals. The proce...
#Nim
Nim
import algorithm import tables   const None = -1 # Index number used to indicate no data.   type   Point = array[3, float] Face = seq[int]   Edge = object pn1: int # Point number 1. pn2: int # Point number 2. fn1: int # Face number 1. fn2: int # Face number 2. cp: Point # Cente...
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#C.2B.2B
C++
#include <iomanip> #include <iostream>   int mod(int n, int d) { return (d + n % d) % d; }   bool is_prime(int n) { if (n < 2) return false; if (n % 2 == 0) return n == 2; if (n % 3 == 0) return n == 3; for (int p = 5; p * p <= n; p += 4) { if (n % p == 0) ...
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: ...
#CLU
CLU
% Reduction. % First type = sequence type (must support S$elements and yield R) % Second type = right (input) datatype % Third type = left (output) datatype reduce = proc [S,R,L: type] (f: proctype (L,R) returns (L), id: L, seq: S) returns (L) ...
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: ...
#Common_Lisp
Common Lisp
; Basic usage > (reduce #'* '(1 2 3 4 5)) 120 ; Using an initial value > (reduce #'+ '(1 2 3 4 5) :initial-value 100) 115 ; Using only a subsequence > (reduce #'+ '(1 2 3 4 5) :start 1 :end 4) 9 ; Apply a function to each element first > (reduce #'+ '((a 1) (b 2) (c 3)) :key #'cadr) 6 ; Right-associative reduction > (r...
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. ...
#Phix
Phix
-- demo\rosetta\Chao_cipher.exw with javascript_semantics constant l_alphabet = "HXUCZVAMDSLKPEFJRIGTWOBNYQ", r_alphabet = "PTLNBQDEOYSFAVZKGJRIHWXUMC" enum ENCRYPT, DECRYPT function chao_cipher(string s, integer mode, bool show_steps) integer len = length(s) string out = repeat(' ',len), ...
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 onl...
#jq
jq
def binomial(n; k): if k > n / 2 then binomial(n; n-k) else reduce range(1; k+1) as $i (1; . * (n - $i + 1) / $i) end;   # Direct (naive) computation using two numbers in Pascal's triangle: def catalan_by_pascal: . as $n | binomial(2*$n; $n) - binomial(2*$n; $n-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 onl...
#Julia
Julia
# v0.6   function pascal(n::Int) r = ones(Int, n, n) for i in 2:n, j in 2:n r[i, j] = r[i-1, j] + r[i, j-1] end return r end   function catalan_num(n::Int) p = pascal(n + 2) p[n+4:n+3:end-1] - diag(p, 2) end   @show catalan_num(15)
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...
#Haskell
Haskell
import Text.Printf   main = printf "The three dogs are named %s, %s and %s.\n" dog dOG dOg where dog = "Benjamin" dOG = "Samba" dOg = "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...
#Icon_and_Unicon
Icon and Unicon
procedure main()   dog := "Benjamin" Dog := "Samba" DOG := "Bernie"   if dog == DOG then write("There is just one dog named ", dog,".") else write("The three dogs are named ", dog, ", ", Dog, " and ", DOG, ".")   end
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 y...
#D
D
import std.stdio;   void main() { auto a = listProduct([1,2], [3,4]); writeln(a);   auto b = listProduct([3,4], [1,2]); writeln(b);   auto c = listProduct([1,2], []); writeln(c);   auto d = listProduct([], [1,2]); writeln(d); }   auto listProduct(T)(T[] ta, T[] tb) { struct Result { ...
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C...
#AutoHotkey
AutoHotkey
Loop 15 out .= "`n" Catalan(A_Index) Msgbox % clipboard := SubStr(out, 2) catalan( n ) { ; By [VxE]. Returns ((2n)! / ((n + 1)! * n!)) if 0 <= N <= 22 (higher than 22 results in overflow) If ( n < 3 ) ; values less than 3 are handled specially Return n < 0 ? "" : n = 0 ? 1 : n   i := 1 ; initialize the accumulato...
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#ActionScript
ActionScript
// Static MyClass.method(someParameter);   // Instance myInstance.method(someParameter);
http://rosettacode.org/wiki/Cantor_set
Cantor set
Task Draw a Cantor set. See details at this Wikipedia webpage:   Cantor set
#ALGOL_68
ALGOL 68
BEGIN # draw a Cantor Set using ASCII # INT lines = 5; # number of lines for the set # # we must choose the line width so that the width of each segment is # # divisible by 3 ( except for the final line where the segment widt...
http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#Go
Go
package main   import ( ed "github.com/Ernyoke/Imger/edgedetection" "github.com/Ernyoke/Imger/imgio" "log" )   func main() { img, err := imgio.ImreadRGBA("Valve_original_(1).png") if err != nil { log.Fatal("Could not read image", err) }   cny, err := ed.CannyRGBA(img, 15, 45, 5) ...
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#C.23
C#
using System; using System.Net; using System.Linq;   public class Program { public static void Main() { string[] tests = { "87.70.141.1/22", "36.18.154.103/12", "62.62.197.11/29", "67.137.119.181/4", "161.214.74.21/24", "184.232.176...
http://rosettacode.org/wiki/Casting_out_nines
Casting out nines
Task   (in three parts) Part 1 Write a procedure (say c o 9 ( x ) {\displaystyle {\mathit {co9}}(x)} ) which implements Casting Out Nines as described by returning the checksum for x {\displaystyle x} . Demonstrate the procedure using the examples given there, or others you may consider lucky. Par...
#FreeBASIC
FreeBASIC
Const base10 = 10 Dim As Integer c1 = 0, c2 = 0, k = 1   For k = 1 To base10^2 c1 += 1 If (k Mod (base10-1) = (k*k) Mod (base10-1)) Then c2 += 1: Print k;" "; Next k   Print Print Using "Intentar ## numeros en lugar de ### numeros ahorra un ##.##%"; c2; c1; 100-(100*c2/c1) Sleep
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
Catmull–Clark subdivision surface
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals. The proce...
#OCaml
OCaml
open Dynar   let add3 (x1, y1, z1) (x2, y2, z2) (x3, y3, z3) = ( (x1 +. x2 +. x3), (y1 +. y2 +. y3), (z1 +. z2 +. z3) )   let mul m (x,y,z) = (m *. x, m *. y, m *. z)   let avg pts = let n, (x,y,z) = List.fold_left (fun (n, (xt,yt,zt)) (xi,yi,zi) -> succ n, (xt +. xi, yt +. yi, zt +. zi))...
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#Clojure
Clojure
  (ns example (:gen-class))   (defn prime? [n] " Prime number test (using Java) " (.isProbablePrime (biginteger n) 16))   (defn carmichael [p1] " Triplets of Carmichael primes, with first element prime p1 " (if (prime? p1) (into [] (for [h3 (range 2 p1) :let [g (+ h3 p1)] d (range 1 g)...
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: ...
#D
D
void main() { import std.stdio, std.algorithm, std.range, std.meta, std.numeric, std.conv, std.typecons;   auto list = iota(1, 11); alias ops = AliasSeq!(q{a + b}, q{a * b}, min, max, gcd);   foreach (op; ops) writeln(op.stringof, ": ", list.reduce!op);   // std.algorithm.reduce s...
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. ...
#Python
Python
# Python3 implementation of Chaocipher # left wheel = ciphertext wheel # right wheel = plaintext wheel   def main(): # letters only! makealpha(key) helps generate lalpha/ralpha. lalpha = "HXUCZVAMDSLKPEFJRIGTWOBNYQ" ralpha = "PTLNBQDEOYSFAVZKGJRIHWXUMC" msg = "WELLDONEISBETTERTHANWELLSAID"   print...
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 onl...
#Kotlin
Kotlin
// version 1.1.2   import java.math.BigInteger   val ONE = BigInteger.ONE   fun pascal(n: Int, k: Int): BigInteger { if (n == 0 || k == 0) return ONE val num = (k + 1..n).fold(ONE) { acc, i -> acc * BigInteger.valueOf(i.toLong()) } val den = (2..n - k).fold(ONE) { acc, i -> acc * BigInteger.valueOf(i.toLong...
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...
#J
J
NB. These variables are all different 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...
#Java
Java
String dog = "Benjamin"; String Dog = "Samba"; //in general, identifiers that start with capital letters are class names String DOG = "Bernie"; //in general, identifiers in all caps are constants //the conventions listed in comments here are not enforced by the language System.out.println("There are three dogs named " ...
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 y...
#Delphi
Delphi
  program Cartesian_product_of_two_or_more_lists;   {$APPTYPE CONSOLE}   uses System.SysUtils;   type TList = TArray<Integer>;   TLists = TArray<TList>;   TListHelper = record helper for TList function ToString: string; end;   TListsHelper = record helper for TLists function ToString(BreakLines: boo...
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C...
#AWK
AWK
# syntax: GAWK -f CATALAN_NUMBERS.AWK BEGIN { for (i=0; i<=15; i++) { printf("%2d %10d\n",i,catalan(i)) } exit(0) } function catalan(n, ans) { if (n == 0) { ans = 1 } else { ans = ((2*(2*n-1))/(n+1))*catalan(n-1) } return(ans) }
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#Ada
Ada
package My_Class is type Object is tagged private; procedure Primitive(Self: Object); -- primitive subprogram procedure Dynamic(Self: Object'Class); procedure Static; private type Object is tagged null record; end My_Class;
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#Apex
Apex
// Static MyClass.method(someParameter);   // Instance myInstance.method(someParameter);
http://rosettacode.org/wiki/Cantor_set
Cantor set
Task Draw a Cantor set. See details at this Wikipedia webpage:   Cantor set
#ALGOL_W
ALGOL W
begin  % draw a Cantor Set using ASCII  % integer LINES;  % number of lines for the set  % integer setWidth;  % width of each line of the set  %  % we must choose the line width so that the width of each segment i...
http://rosettacode.org/wiki/Cantor_set
Cantor set
Task Draw a Cantor set. See details at this Wikipedia webpage:   Cantor set
#AppleScript
AppleScript
------------------------- CANTOR SET -----------------------   -- cantor :: [String] -> [String] on cantor(xs) script go on |λ|(s) set m to (length of s) div 3 set blocks to text 1 thru m of s   if "█" = text 1 of s then {blocks, replicate(m, space), block...
http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#J
J
NB. 2D convolution, filtering, ...   convolve =: 4 : 'x apply (($x) partition y)' partition=: 2 1 3 0 |: {:@[ ]\ 2 1 0 |: {.@[ ]\ ] apply=: [: +/ [: +/ * max3x3 =: 3 : '(0<1{1{y) * (>./>./y)' addborder =: (0&,@|:@|.)^:4 normalize =: ]%+/@, attach =: 3 : 'max3x3 (3 3 partition (addborder y))' unique =: 3 : 'y*i.$y' con...
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#Common_Lisp
Common Lisp
(defun ip->bit-vector (ip) (flet ((int->bits (int) (loop :for i :below 8 :collect (if (logbitp i int) 1 0) :into bits :finally (return (nreverse bits))))) (loop :repeat 4 :with start := 0 :for pos := (position #\. ip :start start) :collect...
http://rosettacode.org/wiki/Casting_out_nines
Casting out nines
Task   (in three parts) Part 1 Write a procedure (say c o 9 ( x ) {\displaystyle {\mathit {co9}}(x)} ) which implements Casting Out Nines as described by returning the checksum for x {\displaystyle x} . Demonstrate the procedure using the examples given there, or others you may consider lucky. Par...
#Free_Pascal
Free Pascal
program castout9; {$ifdef fpc}{$mode delphi}{$endif} uses generics.collections; type TIntegerList = TSortedList<integer>;   procedure co9(const start,base,lim:integer;kaprekars:array of integer); var C1:integer = 0; C2:integer = 0; S:TIntegerlist; k,i:integer; begin S:=TIntegerlist.Create; for k := start ...
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
Catmull–Clark subdivision surface
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals. The proce...
#Phix
Phix
-- demo\rosetta\Catmull_Clark_subdivision_surface.exw with javascript_semantics function newPoint() return {0,0,0} end function function newPointEx() return {newPoint(),0} end function function centerPoint(sequence p1, p2) return sq_div(sq_add(p1, p2), 2) end function function getFacePoints(sequence inputPoints...
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#D
D
enum mod = (in int n, in int m) pure nothrow @nogc=> ((n % m) + m) % m;   bool isPrime(in uint n) pure nothrow @nogc { if (n == 2 || n == 3) return true; else if (n < 2 || n % 2 == 0 || n % 3 == 0) return false; for (uint div = 5, inc = 2; div ^^ 2 <= n; div += inc, inc = 6 - inc) if (n % div == ...
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: ...
#DCL
DCL
$ list = "1,2,3,4,5" $ call reduce list "+" $ show symbol result $ $ numbers = "5,4,3,2,1" $ call reduce numbers "-" $ show symbol result $ $ call reduce list "*" $ show symbol result $ exit $ $ reduce: subroutine $ local_list = 'p1 $ value = f$integer( f$element( 0, ",", local_list )) $ i = 1 $ loop: $ element = f$el...
http://rosettacode.org/wiki/Chaocipher
Chaocipher
Description The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010. The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here. ...
#Raku
Raku
my @left; my @right;   sub reset { @left = <HXUCZVAMDSLKPEFJRIGTWOBNYQ>.comb; @right = <PTLNBQDEOYSFAVZKGJRIHWXUMC>.comb; }   sub encode ($letter) { my $index = @right.first: $letter.uc, :k; my $enc = @left[$index]; $index.&permute; $enc }   sub decode ($letter) { my $index = @left.first:...
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 onl...
#Lua
Lua
function nextrow (t) local ret = {} t[0], t[#t + 1] = 0, 0 for i = 1, #t do ret[i] = t[i - 1] + t[i] end return ret end   function catalans (n) local t, middle = {1} for i = 1, n do middle = math.ceil(#t / 2) io.write(t[middle] - (t[middle + 1] or 0) .. " ") t = nextrow(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...
#JavaScript
JavaScript
var dog = "Benjamin"; var Dog = "Samba"; var DOG = "Bernie"; document.write("The three dogs are named " + 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...
#jq
jq
def task(dog; Dog; DOG): "The three dogs are named \(dog), \(Dog), and \(DOG)." ;   task("Benjamin"; "Samba"; "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 y...
#F.23
F#
  //Nigel Galloway February 12th., 2018 let cP2 n g = List.map (fun (n,g)->[n;g]) (List.allPairs n g)  
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C...
#BASIC
BASIC
DECLARE FUNCTION catalan (n AS INTEGER) AS SINGLE   REDIM SHARED results(0) AS SINGLE   FOR x% = 1 TO 15 PRINT x%, catalan (x%) NEXT   FUNCTION catalan (n AS INTEGER) AS SINGLE IF UBOUND(results) < n THEN REDIM PRESERVE results(n)   IF 0 = n THEN results(0) = 1 ELSE results(n) = ((2 * ((2 * n)...
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#AutoHotkey
AutoHotkey
class myClass { Method(someParameter){ MsgBox % SomeParameter } }   myClass.method("hi") myInstance := new myClass myInstance.Method("bye")
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#Bracmat
Bracmat
( ( myClass = (name=aClass) ( Method = .out$(str$("Output from " !(its.name) ": " !arg)) ) (new=.!arg:?(its.name)) ) & (myClass.Method)$"Example of calling a 'class' method" & new$(myClass,object1):?MyObject & (MyObject..Method)$"Example of calling an instance method" & !MyObject:?Alias & ...
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#C
C
  #include<stdlib.h> #include<stdio.h>   typedef struct{ int x; int (*funcPtr)(int); }functionPair;   int factorial(int num){ if(num==0||num==1) return 1; else return num*factorial(num-1); }   int main(int argc,char** argv) { functionPair response;...
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library
Call a function in a shared library
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function. This is a special case of calling a foreign language function where the focus is c...
#Ada
Ada
with Ada.Text_IO; use Ada.Text_IO; with Interfaces; use Interfaces; with Interfaces.C; use Interfaces.C; with System; use System;   with Ada.Unchecked_Conversion;   procedure Shared_Library_Call is -- -- Interface to kernel32.dll which is responsible for loading DLLs under Windows. -- There are re...
http://rosettacode.org/wiki/Cantor_set
Cantor set
Task Draw a Cantor set. See details at this Wikipedia webpage:   Cantor set
#Arturo
Arturo
width: 81 height: 5   lines: array.of: height repeat `*` width   cantor: function [start length idx].export:[lines][ seg: length / 3 if seg = 0 -> return null   loop idx..dec height 'i [ loop (start + seg).. dec start + 2 * seg 'j -> set lines\[i] j ` ` ] cantor start seg idx+1 ...
http://rosettacode.org/wiki/Calkin-Wilf_sequence
Calkin-Wilf sequence
The Calkin-Wilf sequence contains every nonnegative rational number exactly once. It can be calculated recursively as follows: a1 = 1 an+1 = 1/(2⌊an⌋+1-an) for n > 1 Task part 1 Show on this page terms 1 through 20 of the Calkin-Wilf sequence. To avoid floating point error, you may want to ...
#11l
11l
T CalkinWilf n = 1 d = 1   F ()() V r = (.n, .d) .n = 2 * (.n I/ .d) * .d + .d - .n swap(&.n, &.d) R r   print(‘The first 20 terms of the Calkwin-Wilf sequence are:’) V cw = CalkinWilf() [String] seq L 20 V (n, d) = cw() seq.append(I d == 1 {String(n)} E n‘/’d) print(seq.join(‘, ’...
http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#Java
Java
import java.awt.image.BufferedImage; import java.util.Arrays;   /** * <p><em>This software has been released into the public domain. * <strong>Please read the notes in this source file for additional information. * </strong></em></p> * * <p>This class provides a configurable implementation of the Canny edge * de...
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#Factor
Factor
USING: command-line formatting grouping io kernel math.parser namespaces prettyprint sequences splitting ; IN: rosetta-code.canonicalize-cidr   ! canonicalize a CIDR block: make sure none of the host bits are set command-line get [ lines ] when-empty [  ! ( CIDR-IP -- bits-in-network-part dotted-decimal ) "/" sp...
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#Go
Go
package main   import ( "fmt" "log" "strconv" "strings" )   func check(err error) { if err != nil { log.Fatal(err) } }   // canonicalize a CIDR block: make sure none of the host bits are set func canonicalize(cidr string) string { // dotted-decimal / bits in network part split :=...
http://rosettacode.org/wiki/Casting_out_nines
Casting out nines
Task   (in three parts) Part 1 Write a procedure (say c o 9 ( x ) {\displaystyle {\mathit {co9}}(x)} ) which implements Casting Out Nines as described by returning the checksum for x {\displaystyle x} . Demonstrate the procedure using the examples given there, or others you may consider lucky. Par...
#Go
Go
package main   import ( "fmt" "log" "strconv" )   // A casting out nines algorithm.   // Quoting from: http://mathforum.org/library/drmath/view/55926.html /* First, for any number we can get a single digit, which I will call the "check digit," by repeatedly adding the digits. That is, we add the digits of...
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
Catmull–Clark subdivision surface
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals. The proce...
#Python
Python
  """   Input and output are assumed to be in this form based on the talk page for the task:   input_points = [ [-1.0, 1.0, 1.0], [-1.0, -1.0, 1.0], [ 1.0, -1.0, 1.0], [ 1.0, 1.0, 1.0], [ 1.0, -1.0, -1.0], [ 1.0, 1.0, -1.0], [-1.0, -1.0, -1.0], [-1.0, 1.0, -1.0] ]   input_faces = [ [0, 1, 2, 3...
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#EchoLisp
EchoLisp
  ;; charmichaël numbers up to N-th prime ; 61 is 18-th prime (define (charms (N 18) local: (h31 0) (Prime2 0) (Prime3 0)) (for* ((Prime1 (primes N)) (h3 (in-range 1 Prime1)) (d (+ h3 Prime1))) (set! h31 (+ h3 Prime1)) #:continue (!zero? (modulo (* h31 (1- Prime1)) d)) #:continue (!= (m...
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: ...
#D.C3.A9j.C3.A0_Vu
Déjà Vu
reduce f lst init: if lst: f reduce @f lst init pop-from lst else: init   !. reduce @+ [ 1 10 200 ] 4 !. reduce @- [ 1 10 200 ] 4  
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: ...
#Delphi
Delphi
  ;; rem : the foldX family always need an initial value ;; fold left a list (foldl + 0 (iota 10)) ;; 0 + 1 + .. + 9 → 45   ;; fold left a sequence (lib 'sequences) (foldl * 1 [ 1 .. 10]) → 362880 ;; 10!   ;; folding left and right (foldl / 1 ' ( 1 2 3 4)) → 8/3 (foldr / 1 '(1 2 3 4)) → 3/8   ;;scanl gi...
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. ...
#Ruby
Ruby
txt = "WELLDONEISBETTERTHANWELLSAID" @left = "HXUCZVAMDSLKPEFJRIGTWOBNYQ".chars @right = "PTLNBQDEOYSFAVZKGJRIHWXUMC".chars   def encrypt(char) coded_char = @left[@right.index(char)]   @left.rotate!(@left.index(coded_char)) part = @left.slice!(1,13).rotate @left.insert(1, *part)   @right.rotate!(@right.in...
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 onl...
#M2000_Interpreter
M2000 Interpreter
  Module CatalanNumbers { Def Integer count, t_row, size=31 Dim triangle(1 to size, 1 to size)   \\ call sub pascal_triangle(size, &triangle())     Print "The first 15 Catalan numbers are" count = 1% : t_row = 2%   Do { Print Format$("{0:0:-3}:{1:0:-15}", count, tr...
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 onl...
#Maple
Maple
catalan:=proc(n) local i,a:=[1],C:=[1]; for i to n do a:=[0,op(a)]+[op(a),0]; a:=[0,op(a)]+[op(a),0]; C:=[op(C),a[i+1]-a[i]]; od; C end:   catalan(10); # [1, 1, 2, 5, 14, 42, 132, 429, 1430, 4862, 16796]
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...
#Julia
Julia
dog, Dog, DOG = "Benjamin", "Samba", "Bernie"   if dog === Dog println("There is only one dog, ", DOG) else println("The three dogs are: ", dog, ", ", Dog, " and ", DOG) end
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...
#K
K
  dog: "Benjamin" Dog: "Samba" DOG: "Bernie" "There are three dogs named ",dog,", ",Dog," and ",DOG "There are three dogs 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 y...
#Factor
Factor
IN: scratchpad { 1 2 } { 3 4 } cartesian-product . { { { 1 3 } { 1 4 } } { { 2 3 } { 2 4 } } } IN: scratchpad { 3 4 } { 1 2 } cartesian-product . { { { 3 1 } { 3 2 } } { { 4 1 } { 4 2 } } } IN: scratchpad { 1 2 } { } cartesian-product . { { } { } } IN: scratchpad { } { 1 2 } cartesian-product . { }
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C...
#BASIC256
BASIC256
function factorial(n) if n = 0 then return 1 return n * factorial(n - 1) end function   function catalan1(n) prod = 1 for i = n + 2 to 2 * n prod *= i next i return int(prod / factorial(n)) end function   function catalan2(n) if n = 0 then return 1 sum = 0 for i = 0 to n - 1 ...
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#C.2B.2B
C++
// Static MyClass::method(someParameter);   // Instance myInstance.method(someParameter);   // Pointer MyPointer->method(someParameter);  
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#C_sharp
C_sharp
// Static MyClass.Method(someParameter);   // Instance myInstance.Method(someParameter);
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library
Call a function in a shared library
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function. This is a special case of calling a foreign language function where the focus is c...
#Arturo
Arturo
getCurlVersion: function [][ try? [ call.external:'curl "curl_version" .expect: :string [] ] else [ "library not found" ] ]   print ["curl version:" getCurlVersion]
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library
Call a function in a shared library
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function. This is a special case of calling a foreign language function where the focus is c...
#AutoHotkey
AutoHotkey
ahkdll := DllCall("LoadLibrary", "str", "AutoHotkey.dll") clientHandle := DllCall("AutoHotkey\ahkdll", "str", "dllclient.ahk", "str" , "", "str", "parameter1 parameter2", "Cdecl Int")
http://rosettacode.org/wiki/Cantor_set
Cantor set
Task Draw a Cantor set. See details at this Wikipedia webpage:   Cantor set
#AWK
AWK
  # syntax: GAWK -f CANTOR_SET.AWK # converted from C BEGIN { WIDTH = 81 HEIGHT = 5 for (i=0; i<HEIGHT; ++i) { for (j=0; j<WIDTH; ++j) { lines[i][j] = "*" } } cantor(0,WIDTH,1) for (i=0; i<HEIGHT; ++i) { for (j=0; j<WIDTH; ++j) { printf("%s",lines[i][j]) }...
http://rosettacode.org/wiki/Calkin-Wilf_sequence
Calkin-Wilf sequence
The Calkin-Wilf sequence contains every nonnegative rational number exactly once. It can be calculated recursively as follows: a1 = 1 an+1 = 1/(2⌊an⌋+1-an) for n > 1 Task part 1 Show on this page terms 1 through 20 of the Calkin-Wilf sequence. To avoid floating point error, you may want to ...
#ALGOL_68
ALGOL 68
BEGIN # Show elements 1-20 of the Calkin-Wilf sequence as rational numbers # # also show the position of a specific element in the seuence # # Uses code from the Arithmetic/Rational # # & Continued fraction/Arithmetic/Construct from rational number...
http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#Julia
Julia
using Images   canny_edges = canny(img, sigma = 1.4, upperThreshold = 0.80, lowerThreshold = 0.20)
http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
Export["out.bmp", EdgeDetect[Import[InputString[]]]];
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#Hare
Hare
use fmt; use net::ip; use strings;   export fn main() void = { const array = ["87.70.141.1/22", "36.18.154.103/12", "62.62.197.11/29", "67.137.119.181/4", "161.214.74.21/24", "184.232.176.184/18"];   for (let i = 0z; i < len(array); i += 1) { match (canonicalizecidr(array[i])) { case let s: str => fm...
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#Haskell
Haskell
import Control.Monad (guard) import Data.Bits ((.|.), (.&.), complement, shiftL, shiftR, zeroBits) import Data.Maybe (listToMaybe) import Data.Word (Word32, Word8) import Text.ParserCombinators.ReadP (ReadP, char, readP_to_S) import Text.Printf (printf) import Text.Read.Lex (readDecP)   -- A 32-bit IPv4 address, with a...
http://rosettacode.org/wiki/Casting_out_nines
Casting out nines
Task   (in three parts) Part 1 Write a procedure (say c o 9 ( x ) {\displaystyle {\mathit {co9}}(x)} ) which implements Casting Out Nines as described by returning the checksum for x {\displaystyle x} . Demonstrate the procedure using the examples given there, or others you may consider lucky. Par...
#Haskell
Haskell
co9 n | n <= 8 = n | otherwise = co9 $ sum $ filter (/= 9) $ digits 10 n   task2 = filter (\n -> co9 n == co9 (n ^ 2)) [1 .. 100]   task3 k = filter (\n -> n `mod` k == n ^ 2 `mod` k) [1 .. 100]
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
Catmull–Clark subdivision surface
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals. The proce...
#Rust
Rust
  pub struct Vector3 {pub x: f64, pub y: f64, pub z: f64, pub w: f64}   pub struct Triangle {pub r: [usize; 3], pub(crate) col: [f32; 4], pub(crate) p: [Vector3; 3], n: Vector3, pub t: [Vector2; 3]} pub struct Mesh{pub v: Vec<Vector3>, pub f: Vec<Triangle>}   impl Triangle{ pub fn new() -> Triangle {return Triangle...
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#F.23
F#
  // Carmichael Number . Nigel Galloway: November 19th., 2017 let fN n = Seq.collect ((fun g->(Seq.map(fun e->(n,1+(n-1)*(n+g)/e,g,e))){1..(n+g-1)})){2..(n-1)} let fG (P1,P2,h3,d) = let mod' n g = (n%g+g)%g let fN P3 = if isPrime P3 && (P2*P3)%(P1-1)=1 then Some (P1,P2,P3) else None if isPrime P2 && ((h3+P1)*(P1-...
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: ...
#EchoLisp
EchoLisp
  ;; rem : the foldX family always need an initial value ;; fold left a list (foldl + 0 (iota 10)) ;; 0 + 1 + .. + 9 → 45   ;; fold left a sequence (lib 'sequences) (foldl * 1 [ 1 .. 10]) → 362880 ;; 10!   ;; folding left and right (foldl / 1 ' ( 1 2 3 4)) → 8/3 (foldr / 1 '(1 2 3 4)) → 3/8   ;;scanl gi...
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. ...
#Rust
Rust
const LEFT_ALPHABET_CT: &str = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"; const RIGHT_ALPHABET_PT: &str = "PTLNBQDEOYSFAVZKGJRIHWXUMC"; const ZENITH: usize = 0; const NADIR: usize = 12; const SEQUENCE: &str = "WELLDONEISBETTERTHANWELLSAID";   fn cipher(letter: &char, left: &String, right: &String) -> (usize, char) { let pos = r...
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 onl...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
nextrow[lastrow_] := Module[{output}, output = ConstantArray[1, Length[lastrow] + 1]; Do[ output[[i + 1]] = lastrow[[i]] + lastrow[[i + 1]]; , {i, 1, Length[lastrow] - 1}]; output ] pascaltriangle[size_] := NestList[nextrow, {1}, size] catalannumbers[length_] := Module[{output, basetriangle}, basetria...
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 onl...
#MATLAB_.2F_Octave
MATLAB / Octave
n = 15; p = pascal(n + 2); p(n + 4 : n + 3 : end - 1)' - diag(p, 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...
#Kotlin
Kotlin
fun main(args: Array<String>) { val dog = "Benjamin" val Dog = "Samba" val DOG = "Bernie" println("The three dogs are named $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...
#Lasso
Lasso
  local(dog = 'Benjamin') local(Dog = 'Samba') local(DOG = 'Bernie')   stdoutnl('There is just one dog named ' + #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 y...
#FreeBASIC
FreeBASIC
#define MAXLEN 64   type listitem ' An item of a list may be a number is_num as boolean ' or another list, so I have to account union ' for both, implemented as a union. list as any ptr ' FreeBASIC is twitchy about circularly num as uinteger ...
http://rosettacode.org/wiki/Catalan_numbers
Catalan numbers
Catalan numbers You are encouraged to solve this task according to the task description, using any language you may know. Catalan numbers are a sequence of numbers which can be defined directly: C n = 1 n + 1 ( 2 n n ) = ( 2 n ) ! ( n + 1 ) ! n !  for  n ≥ 0. {\displaystyle C...
#BBC_BASIC
BBC BASIC
10 FOR i% = 1 TO 15 20 PRINT FNcatalan(i%) 30 NEXT 40 END 50 DEF FNcatalan(n%) 60 IF n% = 0 THEN = 1 70 = 2 * (2 * n% - 1) * FNcatalan(n% - 1) / (n% + 1)
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#ChucK
ChucK
  MyClass myClassObject; myClassObject.myFunction(some parameter);  
http://rosettacode.org/wiki/Call_an_object_method
Call an object method
In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class. Show how to call a static or class method, and an instance m...
#Clojure
Clojure
(Long/toHexString 15) ; use forward slash for static methods (System/currentTimeMillis)   (.equals 1 2) ; use dot operator to call instance methods (. 1 (equals 2)) ; alternative style
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library
Call a function in a shared library
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function. This is a special case of calling a foreign language function where the focus is c...
#BaCon
BaCon
' Call a dynamic library function PROTO j0 bessel0 = j0(1.0) PRINT bessel0  
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library
Call a function in a shared library
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function. This is a special case of calling a foreign language function where the focus is c...
#BBC_BASIC
BBC BASIC
SYS "MessageBox", @hwnd%, "This is a test message", 0, 0  
http://rosettacode.org/wiki/Cantor_set
Cantor set
Task Draw a Cantor set. See details at this Wikipedia webpage:   Cantor set
#BASIC
BASIC
10 DEFINT A-Z 20 N = 4 30 W = 3^(N-1) 40 S = W 50 L$ = STRING$(W, "#") 60 PRINT L$ 70 IF S = 1 THEN END 80 S = S\3 90 P = 1 100 IF P >= W-S GOTO 60 110 P = P+S 120 MID$(L$,P,S) = SPACE$(S) 130 P = P+S 140 GOTO 100
http://rosettacode.org/wiki/Calkin-Wilf_sequence
Calkin-Wilf sequence
The Calkin-Wilf sequence contains every nonnegative rational number exactly once. It can be calculated recursively as follows: a1 = 1 an+1 = 1/(2⌊an⌋+1-an) for n > 1 Task part 1 Show on this page terms 1 through 20 of the Calkin-Wilf sequence. To avoid floating point error, you may want to ...
#AppleScript
AppleScript
-- Return the first n terms of the sequence. Tree generation. Faster for this purpose. on CalkinWilfSequence(n) script o property sequence : {{1, 1}} -- Initialised with the first term ({numerator, denominator}). end script   -- Work through the growing sequence list, adding the two children of each...
http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#MATLAB_.2F_Octave
MATLAB / Octave
BWImage = edge(GrayscaleImage,'canny');
http://rosettacode.org/wiki/Canny_edge_detector
Canny edge detector
Task Write a program that performs so-called canny edge detection on an image. A possible algorithm consists of the following steps: Noise reduction.   May be performed by Gaussian filter.   Compute intensity gradient   (matrices G x {\displaystyle G_{x}} and G y {\displaystyle G_{y}} ) ...
#Nim
Nim
import lenientops import math import nimPNG   const MaxBrightness = 255   type Pixel = int16 # Used instead of byte to be able to store negative values.   #---------------------------------------------------------------------------------------------------   func convolution*[normalize: static bool](input: seq[Pixel]...
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#J
J
cidr=: {{ 'a e'=. 0 ".each (y rplc'. ')-.&;:'/' ('/',":e),~rplc&' .'":_8#.\32{.e{.,(8#2)#:a }}
http://rosettacode.org/wiki/Canonicalize_CIDR
Canonicalize CIDR
Task Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form. That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address. Example Given ...
#Java
Java
import java.text.MessageFormat; import java.text.ParseException;   public class CanonicalizeCIDR { public static void main(String[] args) { for (String test : TESTS) { try { CIDR cidr = new CIDR(test); System.out.printf("%-18s -> %s\n", test, cidr.toString()); ...
http://rosettacode.org/wiki/Casting_out_nines
Casting out nines
Task   (in three parts) Part 1 Write a procedure (say c o 9 ( x ) {\displaystyle {\mathit {co9}}(x)} ) which implements Casting Out Nines as described by returning the checksum for x {\displaystyle x} . Demonstrate the procedure using the examples given there, or others you may consider lucky. Par...
#J
J
castout=: 1 :0 [: (#~ ] =&((m-1)&|) *:) <. + [: i. (+*)@-~ )
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface
Catmull–Clark subdivision surface
Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals. The proce...
#Tcl
Tcl
package require Tcl 8.5   # Use math functions and operators as commands (Lisp-like). namespace path {tcl::mathfunc tcl::mathop}   # Add 3 points. proc add3 {A B C} { lassign $A Ax Ay Az lassign $B Bx By Bz lassign $C Cx Cy Cz list [+ $Ax $Bx $Cx] [+ $Ay $By $Cy] [+ $Az $Bz $Cz] }   # Multiply a point b...
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#Factor
Factor
USING: formatting kernel locals math math.primes math.ranges sequences ; IN: rosetta-code.carmichael   :: carmichael ( p1 -- ) 1 p1 (a,b) [| h3 | h3 p1 + [1,b) [| d | h3 p1 + p1 1 - * d mod zero? p1 neg p1 * h3 rem d h3 mod = and [ p1 1 - h3 p1 + * d /i 1 ...
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes
Carmichael 3 strong pseudoprimes
A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it. The   Miller Rabin Test   uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this. The purpose of this task is to investigate such numbers using a met...
#Fortran
Fortran
LOGICAL FUNCTION ISPRIME(N) !Ad-hoc, since N is not going to be big... INTEGER N !Despite this intimidating allowance of 32 bits... INTEGER F !A possible factor. ISPRIME = .FALSE. !Most numbers aren't prime. DO F = 2,SQRT(DFLOAT(N)) !Wince... IF (MOD(N,F).EQ.0) RETURN ...