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http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#Nim
Nim
import os, re   for file in walkDirRec "/": if file.match re".*\.mp3": echo file
http://rosettacode.org/wiki/Water_collected_between_towers
Water collected between towers
Task In a two-dimensional world, we begin with any bar-chart (or row of close-packed 'towers', each of unit width), and then it rains, completely filling all convex enclosures in the chart with water. 9 ██ 9 ██ 8 ██ 8 ██ 7 ██ ...
#Perl
Perl
use Modern::Perl; use List::Util qw{ min max sum };   sub water_collected { my @t = map { { TOWER => $_, LEFT => 0, RIGHT => 0, LEVEL => 0 } } @_;   my ( $l, $r ) = ( 0, 0 ); $_->{LEFT} = ( $l = max( $l, $_->{TOWER} ) ) for @t; $_->{RIGHT} = ( $r = max( $r, $_->{TOWER} ) ) for reverse @t; $_->{LEVE...
http://rosettacode.org/wiki/Vector_products
Vector products
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers:   (X, Y, Z). If you imagine a graph with the   x   and   y   axis being at right angles to each other and having a third,   z   axis coming out of the page, then a triplet of numbers,   (X, Y, Z)   would repr...
#11l
11l
F scalartriplep(a, b, c) return dot(a, cross(b, c))   F vectortriplep(a, b, c) return cross(a, cross(b, c))   V a = (3, 4, 5) V b = (4, 3, 5) V c = (-5, -12, -13)   print(‘a = #.; b = #.; c = #.’.format(a, b, c)) print(‘a . b = #.’.format(dot(a, b))) print(‘a x b = #.’.format(cross(a,b))) print(‘a . (b x c) =...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#PicoLisp
PicoLisp
(de checkDistribution (Cnt Pm . Prg) (let Res NIL (do Cnt (accu 'Res (run Prg 1) 1)) (let (N (/ Cnt (length Res)) Min (*/ N (- 1000 Pm) 1000) Max (*/ N (+ 1000 Pm) 1000) ) (for R Res (prinl (cdr R) " " (if (>= Max (cdr R) Min) "Good" "Bad")) ) ) ) )
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#PureBasic
PureBasic
Prototype RandNum_prt()   Procedure.s distcheck(*function.RandNum_prt, repetitions, delta.d) Protected text.s, maxIndex = 0 Dim bucket(maxIndex) ;array will be resized as needed   For i = 1 To repetitions ;populate buckets v = *function() If v > maxIndex maxIndex = v Redim bucket(maxIndex) ...
http://rosettacode.org/wiki/Variable-length_quantity
Variable-length quantity
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable. Task With above operations, convert these two numbers 0x200000 (209...
#Go
Go
package main   import ( "fmt" "encoding/binary" )   func main() { buf := make([]byte, binary.MaxVarintLen64) for _, x := range []int64{0x200000, 0x1fffff} { v := buf[:binary.PutVarint(buf, x)] fmt.Printf("%d encodes into %d bytes: %x\n", x, len(v), v) x, _ = binary.Varint(v) ...
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#AutoHotkey
AutoHotkey
printAll(args*) { for k,v in args t .= v "`n" MsgBox, %t% }
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#AWK
AWK
function f(a, b, c){ if (a != "") print a if (b != "") print b if (c != "") print c }   BEGIN { print "[1 arg]"; f(1) print "[2 args]"; f(1, 2) print "[3 args]"; f(1, 2, 3) }
http://rosettacode.org/wiki/Vector
Vector
Task Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented. The Vector may be initialized in any reasonable way. Start and end points, and direction Angular coefficient and value (length) The four operations to...
#Delphi
Delphi
  program Vector;   {$APPTYPE CONSOLE}   {$R *.res}   uses System.Math.Vectors, SysUtils;   procedure VectorToString(v: TVector); begin WriteLn(Format('(%.1f + i%.1f)', [v.X, v.Y])); end;   var a, b: TVector;   begin a := TVector.Create(5, 7); b := TVector.Create(2, 3); VectorToString(a + b); VectorToSt...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
TYPE UByte = BITS 8 FOR [0..255];
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Modula-3
Modula-3
TYPE UByte = BITS 8 FOR [0..255];
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Nim
Nim
type MyBitfield = object flag {.bitsize:1.}: cuint
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#ooRexx
ooRexx
default(precision, 1000)
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#PARI.2FGP
PARI/GP
default(precision, 1000)
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Pascal
Pascal
type correctInteger = integer attribute (size = 42);
http://rosettacode.org/wiki/Voronoi_diagram
Voronoi diagram
A Voronoi diagram is a diagram consisting of a number of sites. Each Voronoi site s also has a Voronoi cell consisting of all points closest to s. Task Demonstrate how to generate and display a Voroni diagram. See algo K-means++ clustering.
#Scala
Scala
import java.awt.geom.Ellipse2D import java.awt.image.BufferedImage import java.awt.{Color, Graphics, Graphics2D}   import scala.math.sqrt   object Voronoi extends App { private val (cells, dim) = (100, 1000) private val rand = new scala.util.Random private val color = Vector.fill(cells)(rand.nextInt(0x1000000)) ...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Chi-squared_test
Verify distribution uniformity/Chi-squared test
Task Write a function to verify that a given distribution of values is uniform by using the χ 2 {\displaystyle \chi ^{2}} test to see if the distribution has a likelihood of happening of at least the significance level (conventionally 5%). The function should return a boolean that is true if the distribut...
#Phix
Phix
with javascript_semantics function f(atom aa1, t) return power(t, aa1) * exp(-t) end function function simpson38(atom aa1, a, b, integer n) atom h := (b-a)/n, h1 := h/3, tot := f(aa1,a) + f(aa1,b) for j=3*n-1 to 1 by -1 do tot += (3-(mod(j,3)=0)) * f(aa1,a+h1*j) end for ...
http://rosettacode.org/wiki/Vigen%C3%A8re_cipher
Vigenère cipher
Task Implement a   Vigenère cypher,   both encryption and decryption. The program should handle keys and text of unequal length, and should capitalize everything and discard non-alphabetic characters. (If your program handles non-alphabetic characters in another way, make a note of it.) Related tasks   Caesar ...
#J
J
NB.*vig c Vigenère cipher NB. cipher=. key 0 vig charset plain NB. plain=. key 1 vig charset cipher vig=: conjunction define : r=. (#y) $ n i.x n {~ (#n) | (r*_1^m) + n i.y )   ALPHA=: (65,:26) ];.0 a. NB. Character Set preprocess=: (#~ e.&ALPHA)@toupper NB. force uppercase and discard non-alpha c...
http://rosettacode.org/wiki/Visualize_a_tree
Visualize a tree
A tree structure   (i.e. a rooted, connected acyclic graph)   is often used in programming. It's often helpful to visually examine such a structure. There are many ways to represent trees to a reader, such as:   indented text   (à la unix tree command)   nested HTML tables   hierarchical GUI widgets   2D   or ...
#Maxima
Maxima
load(graphs)$   g: random_tree(10)$   is_tree(g); true   draw_graph(g)$
http://rosettacode.org/wiki/Visualize_a_tree
Visualize a tree
A tree structure   (i.e. a rooted, connected acyclic graph)   is often used in programming. It's often helpful to visually examine such a structure. There are many ways to represent trees to a reader, such as:   indented text   (à la unix tree command)   nested HTML tables   hierarchical GUI widgets   2D   or ...
#Nim
Nim
import strutils   type Node[T] = ref object data: T left, right: Node[T]   proc n[T](data: T; left, right: Node[T] = nil): Node[T] = Node[T](data: data, left: left, right: right)   proc indent[T](n: Node[T]): seq[string] = if n == nil: return @["-- (null)"]   result = @["--" & $n.data]   for a in inde...
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#Standard_ML
Standard ML
fun dirEntries path = let fun loop strm = case OS.FileSys.readDir strm of SOME name => name :: loop strm | NONE => [] val strm = OS.FileSys.openDir path in loop strm before OS.FileSys.closeDir strm end
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#Tcl
Tcl
foreach filename [glob *.txt] { puts $filename }
http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#Objeck
Objeck
use System.IO.File;   class Test { function : Main(args : String[]) ~ Nil { if(args->Size() = 2) { DescendDir(args[0], args[1]); }; }   function : DescendDir(path : String, pattern : String) ~ Nil { files := Directory->List(path); each(i : files) { file := files[i]; if(<>file->St...
http://rosettacode.org/wiki/Water_collected_between_towers
Water collected between towers
Task In a two-dimensional world, we begin with any bar-chart (or row of close-packed 'towers', each of unit width), and then it rains, completely filling all convex enclosures in the chart with water. 9 ██ 9 ██ 8 ██ 8 ██ 7 ██ ...
#Phix
Phix
with javascript_semantics function collect_water(sequence heights) integer res = 0 for i=2 to length(heights)-1 do integer lm = max(heights[1..i-1]), rm = max(heights[i+1..$]), d = min(lm,rm)-heights[i] res += max(0,d) end for return res end function con...
http://rosettacode.org/wiki/Vector_products
Vector products
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers:   (X, Y, Z). If you imagine a graph with the   x   and   y   axis being at right angles to each other and having a third,   z   axis coming out of the page, then a triplet of numbers,   (X, Y, Z)   would repr...
#Action.21
Action!
TYPE Vector=[INT x,y,z]   PROC CreateVector(INT vx,vy,vz Vector POINTER v) v.x=vx v.y=vy v.z=vz RETURN   PROC PrintVector(Vector POINTER v) PrintF("(%I,%I,%I)",v.x,v.y,v.z) RETURN   INT FUNC DotProduct(Vector POINTER v1,v2) INT res   res=v1.x*v2.x  ;calculation split into parts res==+v1.y*v2.y  ;otherwise i...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#Python
Python
from collections import Counter from pprint import pprint as pp   def distcheck(fn, repeats, delta): '''\ Bin the answers to fn() and check bin counts are within +/- delta % of repeats/bincount''' bin = Counter(fn() for i in range(repeats)) target = repeats // len(bin) deltacount = int(delta / 1...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#Quackery
Quackery
[ stack [ 0 0 0 0 0 0 0 ] ] is bins ( --> s )   [ 7 times [ 0 bins take i poke bins put ] ] is emptybins ( --> )   [ bins share over peek 1+ bins take rot poke bins put ] is bincrement ( n --> )   [ emptybins ove...
http://rosettacode.org/wiki/Variable-length_quantity
Variable-length quantity
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable. Task With above operations, convert these two numbers 0x200000 (209...
#Groovy
Groovy
final RADIX = 7 final MASK = 2**RADIX - 1   def octetify = { n -> def octets = [] for (def i = n; i != 0; i >>>= RADIX) { octets << ((byte)((i & MASK) + (octets.empty ? 0 : MASK + 1))) } octets.reverse() }   def deoctetify = { octets -> octets.inject(0) { long n, octet -> (n << RADIX...
http://rosettacode.org/wiki/Variable-length_quantity
Variable-length quantity
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable. Task With above operations, convert these two numbers 0x200000 (209...
#Haskell
Haskell
import Numeric (readOct, showOct) import Data.List (intercalate)   to :: Int -> String to = flip showOct ""   from :: String -> Int from = fst . head . readOct   main :: IO () main = mapM_ (putStrLn . intercalate " <-> " . (pure (:) <*> to <*> (return . show . from . to))) [2097152, 2097151]
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#BaCon
BaCon
' Variadic functions OPTION BASE 1 SUB demo (VAR arg$ SIZE argc) LOCAL x PRINT "Amount of incoming arguments: ", argc FOR x = 1 TO argc PRINT arg$[x] NEXT END SUB   ' No argument demo(0) ' One argument demo("abc") ' Three arguments demo("123", "456", "789")
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#BASIC
BASIC
SUB printAll cdecl (count As Integer, ... ) DIM arg AS Any Ptr DIM i AS Integer   arg = va_first() FOR i = 1 To count PRINT va_arg(arg, Double) arg = va_next(arg, Double) NEXT i END SUB   printAll 3, 3.1415, 1.4142, 2.71828
http://rosettacode.org/wiki/Variable_size/Get
Variable size/Get
Demonstrate how to get the size of a variable. See also: Host introspection
#11l
11l
Int64 i print(T(i).size) print(Int64.size)
http://rosettacode.org/wiki/Vector
Vector
Task Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented. The Vector may be initialized in any reasonable way. Start and end points, and direction Angular coefficient and value (length) The four operations to...
#F.23
F#
open System   let add (ax, ay) (bx, by) = (ax+bx, ay+by)   let sub (ax, ay) (bx, by) = (ax-bx, ay-by)   let mul (ax, ay) c = (ax*c, ay*c)   let div (ax, ay) c = (ax/c, ay/c)   [<EntryPoint>] let main _ = let a = (5.0, 7.0) let b = (2.0, 3.0)   printfn "%A" (add a b) printfn "%A" (sub a ...
http://rosettacode.org/wiki/Vector
Vector
Task Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented. The Vector may be initialized in any reasonable way. Start and end points, and direction Angular coefficient and value (length) The four operations to...
#Factor
Factor
(scratchpad) USE: math.vectors (scratchpad) { 1 2 } { 3 4 } v+   --- Data stack: { 4 6 }
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Perl
Perl
with javascript_semantics requires("1.0.0") include mpfr.e mpfr pi = mpfr_init(0,-121) -- 120 dp, +1 for the "3." mpfr_const_pi(pi) printf(1,"PI with 120 decimals: %s\n\n",mpfr_get_fixed(pi,120))
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Phix
Phix
with javascript_semantics requires("1.0.0") include mpfr.e mpfr pi = mpfr_init(0,-121) -- 120 dp, +1 for the "3." mpfr_const_pi(pi) printf(1,"PI with 120 decimals: %s\n\n",mpfr_get_fixed(pi,120))
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#PicoLisp
PicoLisp
  declare i fixed binary (7), /* occupies 1 byte */ j fixed binary (15), /* occupies 2 bytes */ k fixed binary (31), /* occupies 4 bytes */ l fixed binary (63); /* occupies 8 bytes */   declare d fixed decimal (1), /* occupies 1 byte */ e fixed decimal (3), ...
http://rosettacode.org/wiki/Voronoi_diagram
Voronoi diagram
A Voronoi diagram is a diagram consisting of a number of sites. Each Voronoi site s also has a Voronoi cell consisting of all points closest to s. Task Demonstrate how to generate and display a Voroni diagram. See algo K-means++ clustering.
#Seed7
Seed7
$ include "seed7_05.s7i"; include "draw.s7i"; include "keybd.s7i";   const type: point is new struct var integer: xPos is 0; var integer: yPos is 0; var color: col is black; end struct;   const proc: generateVoronoiDiagram (in integer: width, in integer: height, in integer: numCells) is func local ...
http://rosettacode.org/wiki/Voronoi_diagram
Voronoi diagram
A Voronoi diagram is a diagram consisting of a number of sites. Each Voronoi site s also has a Voronoi cell consisting of all points closest to s. Task Demonstrate how to generate and display a Voroni diagram. See algo K-means++ clustering.
#Sidef
Sidef
require('Imager')   func generate_voronoi_diagram(width, height, num_cells) { var img = %O<Imager>.new(xsize => width, ysize => height) var (nx,ny,nr,ng,nb) = 5.of { [] }...   for i in (^num_cells) { nx << rand(^width) ny << rand(^height) nr << rand(^256) ng << rand(^256) ...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Chi-squared_test
Verify distribution uniformity/Chi-squared test
Task Write a function to verify that a given distribution of values is uniform by using the χ 2 {\displaystyle \chi ^{2}} test to see if the distribution has a likelihood of happening of at least the significance level (conventionally 5%). The function should return a boolean that is true if the distribut...
#Python
Python
import math import random   def GammaInc_Q( a, x): a1 = a-1 a2 = a-2 def f0( t ): return t**a1*math.exp(-t)   def df0(t): return (a1-t)*t**a2*math.exp(-t)   y = a1 while f0(y)*(x-y) >2.0e-8 and y < x: y += .3 if y > x: y = x   h = 3.0e-4 n = int(y/h) h = y/n h...
http://rosettacode.org/wiki/Vigen%C3%A8re_cipher
Vigenère cipher
Task Implement a   Vigenère cypher,   both encryption and decryption. The program should handle keys and text of unequal length, and should capitalize everything and discard non-alphabetic characters. (If your program handles non-alphabetic characters in another way, make a note of it.) Related tasks   Caesar ...
#Java
Java
public class VigenereCipher { public static void main(String[] args) { String key = "VIGENERECIPHER"; String ori = "Beware the Jabberwock, my son! The jaws that bite, the claws that catch!"; String enc = encrypt(ori, key); System.out.println(enc); System.out.println(decrypt(e...
http://rosettacode.org/wiki/Visualize_a_tree
Visualize a tree
A tree structure   (i.e. a rooted, connected acyclic graph)   is often used in programming. It's often helpful to visually examine such a structure. There are many ways to represent trees to a reader, such as:   indented text   (à la unix tree command)   nested HTML tables   hierarchical GUI widgets   2D   or ...
#Perl
Perl
#!/usr/bin/perl use warnings; use strict; use utf8; use open OUT => ':utf8', ':std';   sub parse { my ($tree) = shift; if (my ($root, $children) = $tree =~ /^(.+?)\((.*)\)$/) {   my $depth = 0; for my $pos (0 .. length($children) - 1) { my $char = \substr $children, $pos, 1; ...
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#Toka
Toka
needs shell " ." " .\\.txt$" dir.listByPattern
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#TUSCRIPT
TUSCRIPT
$$ MODE TUSCRIPT files=FILE_NAMES (+,-std-) fileswtxt= FILTER_INDEX (files,":*.txt:",-) txtfiles= SELECT (files,#fileswtxt)
http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#Objective-C
Objective-C
NSString *dir = NSHomeDirectory(); NSDirectoryEnumerator *de = [[NSFileManager defaultManager] enumeratorAtPath:dir];   for (NSString *file in de) if ([[file pathExtension] isEqualToString:@"mp3"]) NSLog(@"%@", file);
http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#OCaml
OCaml
#!/usr/bin/env ocaml #load "unix.cma" #load "str.cma" open Unix   let walk_directory_tree dir pattern = let re = Str.regexp pattern in (* pre-compile the regexp *) let select str = Str.string_match re str 0 in let rec walk acc = function | [] -> (acc) | dir::tail -> let contents = Array.to_list (Sys.rea...
http://rosettacode.org/wiki/Water_collected_between_towers
Water collected between towers
Task In a two-dimensional world, we begin with any bar-chart (or row of close-packed 'towers', each of unit width), and then it rains, completely filling all convex enclosures in the chart with water. 9 ██ 9 ██ 8 ██ 8 ██ 7 ██ ...
#Phixmonti
Phixmonti
include ..\Utilitys.pmt   def collect_water 0 var res len 1 - 2 swap 2 tolist for var i 1 i 1 - slice max >ps len i - 1 + i swap slice max >ps i get ps> ps> min swap - 0 max res + var res endfor drop res enddef   ( ( 1 5 3 7 2 ) ( 5 3 7 2 6 4 5 9 1 2 )...
http://rosettacode.org/wiki/Vector_products
Vector products
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers:   (X, Y, Z). If you imagine a graph with the   x   and   y   axis being at right angles to each other and having a third,   z   axis coming out of the page, then a triplet of numbers,   (X, Y, Z)   would repr...
#Ada
Ada
with Ada.Text_IO;   procedure Vector is type Float_Vector is array (Positive range <>) of Float; package Float_IO is new Ada.Text_IO.Float_IO (Float);   procedure Vector_Put (X : Float_Vector) is begin Ada.Text_IO.Put ("("); for I in X'Range loop Float_IO.Put (X (I), Aft => 1, Exp => 0)...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#R
R
distcheck <- function(fn, repetitions=1e4, delta=3) { if(is.character(fn)) { fn <- get(fn) } if(!is.function(fn)) { stop("fn is not a function") } samp <- fn(n=repetitions) counts <- table(samp) expected <- repetitions/length(counts) lbound <- expected * (1 - 0.01*delta) ...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#Racket
Racket
#lang racket (define (pretty-fraction f) (if (integer? f) f (let* ((d (denominator f)) (n (numerator f)) (q (quotient n d)) (r (remainder n d))) (format "~a ~a" q (/ r d)))))   (define (test-uniformity/naive r n δ) (define observation (make-hash)) (for ((_ (in-range n))) (hash-update! observation (r...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#Raku
Raku
my $d7 = 1..7; sub roll7 { $d7.roll };   my $threshold = 3;   for 14, 105, 1001, 10003, 100002, 1000006 -> $n { dist( $n, $threshold, &roll7 ) };     sub dist ( $n is copy, $threshold, &producer ) { my @dist; my $expect = $n / 7; say "Expect\t",$expect.fmt("%.3f");   loop ($_ = $n; $n; --$n) { @dist...
http://rosettacode.org/wiki/Variable-length_quantity
Variable-length quantity
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable. Task With above operations, convert these two numbers 0x200000 (209...
#Icon_and_Unicon
Icon and Unicon
procedure main() every i := 2097152 | 2097151 | 1 | 127 | 128 | 589723405834 | 165 | 256 do write(image(i)," = ",string2hex(v := uint2vlq(i))," = ",vlq2uint(v)) end   procedure vlq2uint(s) #: decode a variable length quantity if *s > 0 then { i := 0 s ? while h := ord(move(1)) do { if (p...
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#Batch_File
Batch File
  @echo off   :_main call:_variadicfunc arg1 "arg 2" arg-3 pause>nul   :_variadicfunc setlocal for %%i in (%*) do echo %%~i exit /b :: Note: if _variadicfunc was called from cmd.exe with arguments parsed to it, it would only need to contain: :: @for %%i in (%*) do echo %%i  
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#bc
bc
/* Version a */ define f(a[], l) { auto i for (i = 0; i < l; i++) a[i] }   /* Version b */ define g(a[]) { auto i for (i = 0; a[i] != -1; i++) a[i] }   /* Version c */ define h(a[]) { auto i   for (i = 1; i <= a[0]; i++) a[i] }
http://rosettacode.org/wiki/Variable_size/Get
Variable size/Get
Demonstrate how to get the size of a variable. See also: Host introspection
#ActionScript
ActionScript
  package {   import flash.display.Sprite; import flash.events.Event; import flash.sampler.getSize;   public class VariableSizeGet extends Sprite {   public function VariableSizeGet() { if ( stage ) _init(); else addEventListener(Event.ADDED_TO_STAGE, _init); }  ...
http://rosettacode.org/wiki/Variable_size/Get
Variable size/Get
Demonstrate how to get the size of a variable. See also: Host introspection
#Ada
Ada
Int_Bits : constant Integer := Integer'size; Whole_Bytes : constant Integer := Int_Bits / Storage_Unit; -- Storage_Unit is the number of bits per storage element
http://rosettacode.org/wiki/Vector
Vector
Task Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented. The Vector may be initialized in any reasonable way. Start and end points, and direction Angular coefficient and value (length) The four operations to...
#Forth
Forth
: v. swap . . ; : v* swap over * >r * r> ; : v/ swap over / >r / r> ; : v+ >r swap >r + r> r> + ; : v- >r swap >r - r> r> - ;
http://rosettacode.org/wiki/Vector
Vector
Task Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented. The Vector may be initialized in any reasonable way. Start and end points, and direction Angular coefficient and value (length) The four operations to...
#Fortran
Fortran
MODULE ROSETTA_VECTOR IMPLICIT NONE   TYPE VECTOR REAL :: X, Y END TYPE VECTOR     INTERFACE OPERATOR(+) MODULE PROCEDURE VECTOR_ADD END INTERFACE   INTERFACE OPERATOR(-) MODULE PROCEDURE VECTOR_SUB END INTERFACE   INTERFACE OPERATOR(/) MODULE PROCEDURE VECTO...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#PL.2FI
PL/I
  declare i fixed binary (7), /* occupies 1 byte */ j fixed binary (15), /* occupies 2 bytes */ k fixed binary (31), /* occupies 4 bytes */ l fixed binary (63); /* occupies 8 bytes */   declare d fixed decimal (1), /* occupies 1 byte */ e fixed decimal (3), ...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#PureBasic
PureBasic
  EnableExplicit   Structure AllTypes b.b a.a w.w u.u c.c ; character type : 1 byte on x86, 2 bytes on x64 l.l i.i ; integer type : 4 bytes on x86, 8 bytes on x64 q.q f.f d.d s.s ; pointer to string on heap : pointer size same as integer z.s{2} ; fixed length string of 2 characters, sto...
http://rosettacode.org/wiki/Voronoi_diagram
Voronoi diagram
A Voronoi diagram is a diagram consisting of a number of sites. Each Voronoi site s also has a Voronoi cell consisting of all points closest to s. Task Demonstrate how to generate and display a Voroni diagram. See algo K-means++ clustering.
#Tcl
Tcl
package require Tk proc r to {expr {int(rand()*$to)}}; # Simple helper   proc voronoi {photo pointCount} { for {set i 0} {$i < $pointCount} {incr i} { lappend points [r [image width $photo]] [r [image height $photo]] } foreach {x y} $points { lappend colors [format "#%02x%02x%02x" [r 256] [r 256] [r 256...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Chi-squared_test
Verify distribution uniformity/Chi-squared test
Task Write a function to verify that a given distribution of values is uniform by using the χ 2 {\displaystyle \chi ^{2}} test to see if the distribution has a likelihood of happening of at least the significance level (conventionally 5%). The function should return a boolean that is true if the distribut...
#R
R
  dset1=c(199809,200665,199607,200270,199649) dset2=c(522573,244456,139979,71531,21461)   chi2IsUniform<-function(dataset,significance=0.05){ chi2IsUniform=(chisq.test(dataset)$p.value>significance) }   for (ds in list(dset1,dset2)){ print(c("Data set:",ds)) print(chisq.test(ds)) print(paste("uniform?",chi2IsUn...
http://rosettacode.org/wiki/Vigen%C3%A8re_cipher
Vigenère cipher
Task Implement a   Vigenère cypher,   both encryption and decryption. The program should handle keys and text of unequal length, and should capitalize everything and discard non-alphabetic characters. (If your program handles non-alphabetic characters in another way, make a note of it.) Related tasks   Caesar ...
#JavaScript
JavaScript
// helpers // helper function ordA(a) { return a.charCodeAt(0) - 65; }   // vigenere function vigenere(text, key, decode) { var i = 0, b; key = key.toUpperCase().replace(/[^A-Z]/g, ''); return text.toUpperCase().replace(/[^A-Z]/g, '').replace(/[A-Z]/g, function(a) { b = key[i++ % key.length]; return Str...
http://rosettacode.org/wiki/Visualize_a_tree
Visualize a tree
A tree structure   (i.e. a rooted, connected acyclic graph)   is often used in programming. It's often helpful to visually examine such a structure. There are many ways to represent trees to a reader, such as:   indented text   (à la unix tree command)   nested HTML tables   hierarchical GUI widgets   2D   or ...
#Phix
Phix
-- -- demo\rosetta\VisualiseTree.exw -- with javascript_semantics -- To the theme tune of the Milk Tray Ad iyrt, -- All because the Windows console hates utf8: constant TL = '\#DA', -- aka '┌' VT = '\#B3', -- aka '│' BL = '\#C0', -- aka '└' HZ = '\#C4', -- aka '─' ...
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#TXR
TXR
(glob "/etc/*.conf")
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#UNIX_Shell
UNIX Shell
ls -d *.c # *.c files in current directory (cd mydir && ls -d *.c) # *.c files in mydir
http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#ooRexx
ooRexx
/* REXX --------------------------------------------------------------- * List all file names on my disk D: that contain the string TTTT *--------------------------------------------------------------------*/ call SysFileTree "d:\*.*", "file", "FS" -- F get all Files -- S search ...
http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#Oz
Oz
declare [Path] = {Module.link ['x-oz://system/os/Path.ozf']} [Regex] = {Module.link ['x-oz://contrib/regex']}   proc {WalkDirTree Root Pattern Proc} proc {Walk R} Entries = {Path.readdir R} Files = {Filter Entries Path.isFile} MatchingFiles = {Filter Files fun {$ File} {Regex.search P...
http://rosettacode.org/wiki/Water_collected_between_towers
Water collected between towers
Task In a two-dimensional world, we begin with any bar-chart (or row of close-packed 'towers', each of unit width), and then it rains, completely filling all convex enclosures in the chart with water. 9 ██ 9 ██ 8 ██ 8 ██ 7 ██ ...
#PicoLisp
PicoLisp
(de water (Lst) (sum '((A) (cnt nT (clip (mapcar '((B) (>= B A)) Lst)) ) ) (range 1 (apply max Lst)) ) ) (println (mapcar water (quote (1 5 3 7 2) (5 3 7 2 6 4 5 9 1 2) (2 6 3 5 2 8 1 4 2 2 5 3 5 7 4 1) (5 5 5 5) ...
http://rosettacode.org/wiki/Vector_products
Vector products
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers:   (X, Y, Z). If you imagine a graph with the   x   and   y   axis being at right angles to each other and having a third,   z   axis coming out of the page, then a triplet of numbers,   (X, Y, Z)   would repr...
#ALGOL_68
ALGOL 68
MODE FIELD = INT; FORMAT field fmt = $g(-0)$;   MODE VEC = [3]FIELD; FORMAT vec fmt = $"("f(field fmt)", "f(field fmt)", "f(field fmt)")"$;   PROC crossp = (VEC a, b)VEC:( #Cross product of two 3D vectors# CO ASSERT(LWB a = LWB b AND UPB a = UPB b AND UPB b = 3 # "For 3D vectors only" #); CO (a[2]*b[3] - a[...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#REXX
REXX
/*REXX program simulates a number of trials of a random digit and show it's skew %. */ parse arg func times delta seed . /*obtain arguments (options) from C.L. */ if func=='' | func=="," then func= 'RANDOM' /*function not specified? Use default.*/ if times=='' | times=="," then times= 1000000...
http://rosettacode.org/wiki/Variable-length_quantity
Variable-length quantity
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable. Task With above operations, convert these two numbers 0x200000 (209...
#J
J
N=: 128x v2i=: (N&| N&#./.~ [: +/\ _1 |. N&>)@i.~&a. i2v=: a. {~ [:;}.@(N+//.@,:N&#.inv)&.> ifv=: v2i :. i2v vfi=: i2v :. v2i
http://rosettacode.org/wiki/Variable-length_quantity
Variable-length quantity
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable. Task With above operations, convert these two numbers 0x200000 (209...
#Java
Java
public class VLQCode { public static byte[] encode(long n) { int numRelevantBits = 64 - Long.numberOfLeadingZeros(n); int numBytes = (numRelevantBits + 6) / 7; if (numBytes == 0) numBytes = 1; byte[] output = new byte[numBytes]; for (int i = numBytes - 1; i >= 0; i--) { int curBy...
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#BCPL
BCPL
get "libhdr"   // A, B, C, etc are dummy arguments. If more are needed, more can be added. // Eventually you will run into the compiler limit. let foo(num, A, B, C, D, E, F, G, H, I, J, K, L, M, N, O) be // The arguments can be indexed starting from the first one. for i=1 to num do writef("%S*N", (@num)!i)   ...
http://rosettacode.org/wiki/Variadic_function
Variadic function
Task Create a function which takes in a variable number of arguments and prints each one on its own line. Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime. Functions of this type are also known as Variadic Functions. Related task   Call a function...
#BQN
BQN
Fun1 ← •Show¨ Fun2 ← {•Show¨𝕩} Fun3 ← { 1=≠𝕩 ? •Show 𝕩; "too many arguments " ! 𝕩}
http://rosettacode.org/wiki/Variable_size/Get
Variable size/Get
Demonstrate how to get the size of a variable. See also: Host introspection
#ALGOL_68
ALGOL 68
INT i; BYTES b; # typically INT and BYTES are the same size # STRING s:="DCLXVI", [666]CHAR c; print(( "sizeof INT i =",bytes width, new line, "UPB STRING s =",UPB s, new line, "UPB []CHAR c =",UPB c, new line ))
http://rosettacode.org/wiki/Variable_size/Get
Variable size/Get
Demonstrate how to get the size of a variable. See also: Host introspection
#AutoHotkey
AutoHotkey
VarSetCapacity(Var, 10240000) ; allocate 10 megabytes MsgBox % size := VarSetCapacity(Var) ; 10240000
http://rosettacode.org/wiki/Variable_size/Get
Variable size/Get
Demonstrate how to get the size of a variable. See also: Host introspection
#Babel
Babel
main: { (1 2 (3 4) 5 6) dup mu disp dup nva disp dup npt disp dup nlf disp dup nin disp dup nhref disp dup nhword disp }   disp! : { %d cr << }  
http://rosettacode.org/wiki/Vector
Vector
Task Implement a Vector class (or a set of functions) that models a Physical Vector. The four basic operations and a pretty print function should be implemented. The Vector may be initialized in any reasonable way. Start and end points, and direction Angular coefficient and value (length) The four operations to...
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   Type Vector As Double x, y Declare Operator Cast() As String End Type   Operator Vector.Cast() As String Return "[" + Str(x) + ", " + Str(y) + "]" End Operator   Operator + (vec1 As Vector, vec2 As Vector) As Vector Return Type<Vector>(vec1.x + vec2.x, vec1.y + vec2.y) End Operator   Operat...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Python
Python
/*REXX program demonstrates on setting a variable (using a "minimum var size".*/ numeric digits 100 /*default: 9 (decimal digs) for numbers*/   /*── 1 2 3 4 5 6 7──*/ /*──1234567890123456789012345678901234567890123456789012345678901234567890──*...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Racket
Racket
/*REXX program demonstrates on setting a variable (using a "minimum var size".*/ numeric digits 100 /*default: 9 (decimal digs) for numbers*/   /*── 1 2 3 4 5 6 7──*/ /*──1234567890123456789012345678901234567890123456789012345678901234567890──*...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Raku
Raku
/*REXX program demonstrates on setting a variable (using a "minimum var size".*/ numeric digits 100 /*default: 9 (decimal digs) for numbers*/   /*── 1 2 3 4 5 6 7──*/ /*──1234567890123456789012345678901234567890123456789012345678901234567890──*...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#REXX
REXX
/*REXX program demonstrates on setting a variable (using a "minimum var size".*/ numeric digits 100 /*default: 9 (decimal digs) for numbers*/   /*── 1 2 3 4 5 6 7──*/ /*──1234567890123456789012345678901234567890123456789012345678901234567890──*...
http://rosettacode.org/wiki/Variable_size/Set
Variable size/Set
Task Demonstrate how to specify the minimum size of a variable or a data type.
#Scala
Scala
/* Ranges for variables of the primitive numeric types */ println(s"A Byte variable has a range of : ${Byte.MinValue} to ${Byte.MaxValue}") println(s"A Short variable has a range of : ${Short.MinValue} to ${Short.MaxValue}") println(s"An Int variable has a range of : ${Int.MinValue} to ${Int.MaxValue}") prin...
http://rosettacode.org/wiki/Voronoi_diagram
Voronoi diagram
A Voronoi diagram is a diagram consisting of a number of sites. Each Voronoi site s also has a Voronoi cell consisting of all points closest to s. Task Demonstrate how to generate and display a Voroni diagram. See algo K-means++ clustering.
#Wren
Wren
import "graphics" for Canvas, Color import "dome" for Window import "random" for Random   class Game { static init() { Window.title = "Voronoi diagram" var cells = 70 var size = 700 Window.resize(size, size) Canvas.resize(size, size) voronoi(cells, size) }   s...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Chi-squared_test
Verify distribution uniformity/Chi-squared test
Task Write a function to verify that a given distribution of values is uniform by using the χ 2 {\displaystyle \chi ^{2}} test to see if the distribution has a likelihood of happening of at least the significance level (conventionally 5%). The function should return a boolean that is true if the distribut...
#Racket
Racket
  #lang racket (require racket/flonum (planet williams/science:4:5/science) (only-in (planet williams/science/unsafe-ops-utils) real->float))   ; (chi^2-goodness-of-fit-test observed expected df) ; Given: observed, a sequence of observed frequencies ; expected, a sequence of expected frequencies ; ...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Chi-squared_test
Verify distribution uniformity/Chi-squared test
Task Write a function to verify that a given distribution of values is uniform by using the χ 2 {\displaystyle \chi ^{2}} test to see if the distribution has a likelihood of happening of at least the significance level (conventionally 5%). The function should return a boolean that is true if the distribut...
#Raku
Raku
sub incomplete-γ-series($s, $z) { my \numers = $z X** 1..*; my \denoms = [\*] $s X+ 1..*; my $M = 1 + [+] (numers Z/ denoms) ... * < 1e-6; $z**$s / $s * exp(-$z) * $M; }   sub postfix:<!>(Int $n) { [*] 2..$n }   sub Γ-of-half(Int $n where * > 0) { ($n %% 2) ?? (($_-1)! giv...
http://rosettacode.org/wiki/Vigen%C3%A8re_cipher
Vigenère cipher
Task Implement a   Vigenère cypher,   both encryption and decryption. The program should handle keys and text of unequal length, and should capitalize everything and discard non-alphabetic characters. (If your program handles non-alphabetic characters in another way, make a note of it.) Related tasks   Caesar ...
#jq
jq
def vigenere(text; key; encryptp): # retain alphabetic characters only def n: ascii_upcase | explode | map(select(65 <= . and . <= 90)) | [., length]; (text | n) as [$xtext, $length] | (key | n) as [$xkey, $keylength] | reduce range(0; $length) as $i (null; ($i % $keylength) as $ki | . + [if encryptp ...
http://rosettacode.org/wiki/Vigen%C3%A8re_cipher
Vigenère cipher
Task Implement a   Vigenère cypher,   both encryption and decryption. The program should handle keys and text of unequal length, and should capitalize everything and discard non-alphabetic characters. (If your program handles non-alphabetic characters in another way, make a note of it.) Related tasks   Caesar ...
#Jsish
Jsish
/* Vigenère cipher, in Jsish */ "use strict";   function ordA(a:string):number { return a.charCodeAt(0) - 65; }   // vigenere function vigenereCipher(text:string, key:string, decode:boolean=false):string { var i = 0, b; key = key.toUpperCase().replace(/[^A-Z]/g, ''); return text.toUpperCase().replace(/[...
http://rosettacode.org/wiki/Visualize_a_tree
Visualize a tree
A tree structure   (i.e. a rooted, connected acyclic graph)   is often used in programming. It's often helpful to visually examine such a structure. There are many ways to represent trees to a reader, such as:   indented text   (à la unix tree command)   nested HTML tables   hierarchical GUI widgets   2D   or ...
#PicoLisp
PicoLisp
(view '(1 (2 (3 (4) (5) (6 (7))) (8 (9)) (10)) (11 (12) (13))))
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#UnixPipes
UnixPipes
ls | grep '\.c$'
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively
Walk a directory/Non-recursively
Task Walk a given directory and print the names of files matching a given pattern. (How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?) Note: This task is for non-recursive methods.   These tasks should read a single directory, not an entire directory tree. ...
#VBScript
VBScript
  Sub show_files(folder_path,pattern) Set objfso = CreateObject("Scripting.FileSystemObject") For Each file In objfso.GetFolder(folder_path).Files If InStr(file.Name,pattern) Then WScript.StdOut.WriteLine file.Name End If Next End Sub   Call show_files("C:\Windows",".exe")  
http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#Perl
Perl
use File::Find qw(find); my $dir = '.'; my $pattern = 'foo'; my $callback = sub { print $File::Find::name, "\n" if /$pattern/ }; find $callback, $dir;
http://rosettacode.org/wiki/Walk_a_directory/Recursively
Walk a directory/Recursively
Task Walk a given directory tree and print files matching a given pattern. Note: This task is for recursive methods.   These tasks should read an entire directory tree, not a single directory. Note: Please be careful when running any code examples found here. Related task   Walk a directory/Non-recursively   ...
#Phix
Phix
function find_pfile(string pathname, sequence dirent) if match("pfile.e",dirent[D_NAME]) then -- return pathname&dirent[D_NAME] -- as below ?pathname&"\\"&dirent[D_NAME] end if return 0 -- non-zero terminates scan end function ?walk_dir("C:\\Program Files (x86)\\Phix",find_pfile,1)
http://rosettacode.org/wiki/Water_collected_between_towers
Water collected between towers
Task In a two-dimensional world, we begin with any bar-chart (or row of close-packed 'towers', each of unit width), and then it rains, completely filling all convex enclosures in the chart with water. 9 ██ 9 ██ 8 ██ 8 ██ 7 ██ ...
#Python
Python
def water_collected(tower): N = len(tower) highest_left = [0] + [max(tower[:n]) for n in range(1,N)] highest_right = [max(tower[n:N]) for n in range(1,N)] + [0] water_level = [max(min(highest_left[n], highest_right[n]) - tower[n], 0) for n in range(N)] print("highest_left: ", highest_left) ...
http://rosettacode.org/wiki/Vector_products
Vector products
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers:   (X, Y, Z). If you imagine a graph with the   x   and   y   axis being at right angles to each other and having a third,   z   axis coming out of the page, then a triplet of numbers,   (X, Y, Z)   would repr...
#ALGOL_W
ALGOL W
begin  % define the Vector record type  % record Vector( integer X, Y, Z );    % calculates the dot product of two Vectors  % integer procedure dotProduct( reference(Vector) value A, B ) ; ( X(A) * X(B) ) + ( Y(A) * Y(B) ) + ( Z(A...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#Ring
Ring
  # Project : Verify distribution uniformity/Naive   maxrnd = 7 for r = 2 to 5 check = distcheck(pow(10,r), 0.05) see "over " + pow(10,r) + " runs dice5 " + nl if check see "failed distribution check with " + check + " bin(s) out of range" + nl else see "passed distribution check" + nl ...
http://rosettacode.org/wiki/Verify_distribution_uniformity/Naive
Verify distribution uniformity/Naive
This task is an adjunct to Seven-sided dice from five-sided dice. Task Create a function to check that the random integers returned from a small-integer generator function have uniform distribution. The function should take as arguments: The function (or object) producing random integers. The number of times ...
#Ruby
Ruby
def distcheck(n, delta=1) unless block_given? raise ArgumentError, "pass a block to this method" end   h = Hash.new(0) n.times {h[ yield ] += 1}   target = 1.0 * n / h.length h.each do |key, value| if (value - target).abs > 0.01 * delta * n raise StandardError, "distribution potential...
http://rosettacode.org/wiki/Variable_declaration_reset
Variable declaration reset
A decidely non-challenging task to highlight a potential difference between programming languages. Using a straightforward longhand loop as in the JavaScript and Phix examples below, show the locations of elements which are identical to the immediately preceding element in {1,2,2,3,4,4,5}. The (non-blank) results may ...
#ALGOL_68
ALGOL 68
BEGIN []INT s = ( 1, 2, 2, 3, 4, 4, 5 ); FOR i FROM LWB s TO UPB s DO INT curr := s[ i ], prev; IF IF i > LWB s THEN curr = prev ELSE FALSE FI THEN print( ( i, newline ) ) FI; prev := curr OD END
http://rosettacode.org/wiki/Variable-length_quantity
Variable-length quantity
Implement some operations on variable-length quantities, at least including conversions from a normal number in the language to the binary representation of the variable-length quantity for that number, and vice versa. Any variants are acceptable. Task With above operations, convert these two numbers 0x200000 (209...
#JavaScript
JavaScript
const RADIX = 7; const MASK = 2**RADIX - 1;   const octetify = (n)=> { if (n >= 2147483648) { throw new RangeError("Variable Length Quantity not supported for numbers >= 2147483648"); } const octets = []; for (let i = n; i != 0; i >>>= RADIX) { octets.push((((i & MASK) + (octets.empty ? 0 : (MASK + 1))))); } ...