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http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Pop11
Pop11
uses objectclass; define :class Delegator; slot delegate = false; enddefine;   define :class Delegate; enddefine;   define :method thing(x : Delegate); 'delegate implementation' enddefine;   define :method operation(x : Delegator); if delegate(x) and fail_safe(delegate(x), thing) then  ;;; Return value is on t...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Python
Python
class Delegator: def __init__(self): self.delegate = None def operation(self): if hasattr(self.delegate, 'thing') and callable(self.delegate.thing): return self.delegate.thing() return 'default implementation'   class Delegate: def thing(self): return 'delegate implementatio...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Racket
Racket
#lang racket ;; Delegates. Tim Brown 2014-10-16   (define delegator% (class object% (init-field [delegate #f]) (define/public (operation) (cond [(and (object? delegate) (object-method-arity-includes? delegate 'thing 0)) (send delegate thing)] [else "default implementation"])) ...
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)...
#Racket
Racket
#lang racket   ;; A triangle is a list of three pairs of points: '((x . y) (x . y) (x . y)) (define (to-tri x1 y1 x2 y2 x3 y3) `((,x1 . ,y1) (,x2 . ,y2) (,x3 . ,y3)))   (define det-2D (match-lambda [`((,x1 . ,y1) (,x2 . ,y2) (,x3 . ,y3)) (+ (* x1 (- y2 y3)) (* x2 (- y3 y1)) (* x3 (- y1 y2)))]))   (define (assert-...
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#JavaScript
JavaScript
var fso = new ActiveXObject("Scripting.FileSystemObject");   fso.DeleteFile('input.txt'); fso.DeleteFile('c:/input.txt');   fso.DeleteFolder('docs'); fso.DeleteFolder('c:/docs');
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Julia
Julia
  # Delete a file rm("input.txt")   # Delete a directory rm("docs", recursive = true)  
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#REXX
REXX
/* REXX *************************************************************** * Test the two functions determinant and permanent * using the matrix specifications shown for other languages * 21.05.2013 Walter Pachl **********************************************************************/ Call test ' 1 2', ' 3 4',2 ...
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#Ruby
Ruby
require 'matrix'   class Matrix # Add "permanent" method to Matrix class def permanent r = (0...row_count).to_a # [0,1] (first example), [0,1,2,3] (second example) r.permutation.inject(0) do |sum, sigma| sum += sigma.zip(r).inject(1){|prod, (row, col)| prod *= self[row, col] } end end end   m1 ...
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Lua
Lua
local function div(a,b) if b == 0 then error() end return a/b end
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#M2000_Interpreter
M2000 Interpreter
  Print function("{Read x : =x**2}", 2)=4  
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#M4
M4
ifelse(eval(2/0),`',`detected divide by zero or some other error of some kind')
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#Haxe
Haxe
  static function isNumeric(n:String):Bool { if (Std.parseInt(n) != null) //Std.parseInt converts a string to an int { return true; //as long as it results in an integer, the function will return true } else { return false; } }  
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#HicEst
HicEst
! = bin + 2*int + 4*flt + 8*oct +16*hex + 32*sci isNumeric("1001") ! 27 = 1 1 0 1 1 0 isNumeric("123") ! 26 = 0 1 0 1 1 0 isNumeric("1E78") ! 48 = 0 0 0 0 1 ...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being ...
#Python
Python
'''Determine if a string has all unique characters'''   from itertools import groupby     # duplicatedCharIndices :: String -> Maybe (Char, [Int]) def duplicatedCharIndices(s): '''Just the first duplicated character, and the indices of its occurrence, or Nothing if there are no duplications. ''' ...
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediatel...
#XPL0
XPL0
string 0; char C, I, J, Last;   proc Collapse(S); \Eliminate immediately repeated characters from string char S; [I:= 0; J:= 0; Last:= -1; loop [if S(I) # Last then [C(J):= S(I); if S(I) = 0 then quit; J:= J+1; ]; Last:= S(I); I:= I+1; ]; ];   int String, K; [Strin...
http://rosettacode.org/wiki/Determine_if_a_string_is_collapsible
Determine if a string is collapsible
Determine if a character string is   collapsible. And if so,   collapse the string   (by removing   immediately repeated   characters). If a character string has   immediately repeated   character(s),   the repeated characters are to be deleted (removed),   but not the primary (1st) character(s). An   immediatel...
#zkl
zkl
fcn collapsible(str){ // no Unicode sink:=Sink(String); str.reduce('wrap(c1,c2){ if(c1!=c2) sink.write(c2); c2 },""); // prime with \0 cstr:=sink.close(); return(str.len()!=cstr.len(), cstr); }
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#Racket
Racket
#lang racket   (define (first-non-matching-index l =) (and (not (null? l)) (index-where l (curry (negate =) (car l)))))   (define (report-string-sameness s) (printf "~s (length: ~a): ~a~%" s (string-length s) (cond [(first-non-matching-index (string->list s) char=?) =>...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#Raku
Raku
-> $str { my $i = 0; print "\n{$str.raku} (length: {$str.chars}), has "; my %m; %m{$_}.push: ++$i for $str.comb;   if %m > 1 { say "different characters:"; say "'{.key}' ({.key.uninames}; hex ordinal: {(.key.ords).fmt: "0x%X"})" ~ " in positions: {.value.join: ', '}" for %m...
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou...
#Smalltalk
Smalltalk
'From Squeak3.7 of ''4 September 2004'' [latest update: #5989] on 13 October 2011 at 2:44:42 pm'! Object subclass: #Philosopher instanceVariableNames: 'table random name seat forks running' classVariableNames: '' poolDictionaries: '' category: 'rosettacode'!   !Philosopher methodsFor: 'private'! createfork ^ Semap...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Rust
Rust
extern crate chrono;   use chrono::NaiveDate; use std::str::FromStr;   fn main() { let date = std::env::args().nth(1).expect("Please provide a YYYY-MM-DD date."); println!("{} is {}", date, NaiveDate::from_str(&date).unwrap().to_poee()); }   // The necessary constants for the seasons, weekdays, and holydays. co...
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro...
#Sidef
Sidef
class Graph(*args) {   struct Node { String name, Array edges = [], Number dist = Inf, prev = nil, Bool visited = false, }   struct Edge { Number weight, Node vertex, }   has g = Hash()   method init { args.each { |a| se...
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displ...
#PowerShell
PowerShell
function Get-DigitalRoot ($n) { function Get-Digitalsum ($n) { if ($n -lt 10) {$n} else { ($n % 10) + (Get-DigitalSum ([math]::Floor($n / 10))) } }   $ap = 0 do {$n = Get-DigitalSum $n; $ap++} until ($n -lt 10) $DigitalRoot = [pscustomobject]@{ 'Su...
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of...
#UTFool
UTFool
  ··· http://rosettacode.org/wiki/Dinesman's_multiple-dwelling_problem ··· import java.util.HashSet   ■ Dinesman § static   houses⦂ HashSet⟨String⟩°   ▶ main • args⦂ String[] · Baker, Cooper, Fletcher, Miller, and Smith … build *StringBuilder°, *StringBuilder "BCFMS" ∀ house ∈ houses⦂ St...
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot ...
#.D0.9C.D0.9A-61.2F52
МК-61/52
С/П * ИП0 + П0 С/П БП 00
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot ...
#Modula-2
Modula-2
MODULE DotProduct; FROM RealStr IMPORT RealToStr; FROM Terminal IMPORT WriteString,WriteLn,ReadChar;   TYPE Vector = RECORD x,y,z : REAL END;   PROCEDURE DotProduct(u,v : Vector) : REAL; BEGIN RETURN u.x*v.x + u.y*v.y + u.z*v.z END DotProduct;   VAR buf : ARRAY[0..63] OF CHAR; dp : REAL; BEG...
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and mu...
#FOCAL
FOCAL
01.10 F P=2,2,6;F S=1,7;F G=1,7;D 2 01.20 Q   02.10 I (P-S)2.2,2.6,2.2 02.20 I (P-G)2.3,2.6,2.3 02.30 I (S-G)2.4,2.6,2.4 02.40 I (P+S+G-12)2.6,2.5,2.6 02.50 T %1,P,S,G,! 02.60 R
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and mu...
#Forth
Forth
\ if department numbers are valid, print them on a single line : fire ( pol san fir -- ) 2dup = if 2drop drop exit then 2 pick over = if 2drop drop exit then rot . swap . . cr ;   \ tries to assign numbers with given policeno and sanitationno \ and fire = 12 - policeno - sanitationno : sanitation ( pol san ...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Raku
Raku
class Non-Delegate { }   class Delegate { method thing { return "delegate implementation" } }   class Delegator { has $.delegate is rw;   method operation { $.delegate.^can( 'thing' ) ?? $.delegate.thing !! "default implementation" } }   my Delegator $d .= new;   say "empty: "~$d.operation;   $d.delegate = ...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Ruby
Ruby
class Delegator attr_accessor :delegate def operation if @delegate.respond_to?(:thing) @delegate.thing else 'default implementation' end end end   class Delegate def thing 'delegate implementation' end end   if __FILE__ == $PROGRAM_NAME   # No delegate a = ...
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)...
#Raku
Raku
# Reference: # https://stackoverflow.com/questions/2049582/how-to-determine-if-a-point-is-in-a-2d-triangle # https://www.geeksforgeeks.org/check-if-two-given-line-segments-intersect/   sub if-overlap ($triangle-pair) { my (\A,\B) = $triangle-pair; my Bool $result = False;   sub sign (\T) { return (T[0;0]...
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Kotlin
Kotlin
// version 1.0.6   /* testing on Windows 10 which needs administrative privileges to delete files from the root */   import java.io.File   fun main(args: Array<String>) { val paths = arrayOf("input.txt", "docs", "c:\\input.txt", "c:\\docs") var f: File for (path in paths) { f = File(path) ...
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#LabVIEW
LabVIEW
// delete file local(f = file('input.txt')) #f->delete   // delete directory // directory must be empty before it can be successfully deleted. A failure is generated if the operation fails. local(d = dir('docs')) #d->delete   // delete file in root file system (requires permissions at user OS level) local(f = file('//i...
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#Rust
Rust
  fn main() { let mut m1: Vec<Vec<f64>> = vec![vec![1.0,2.0],vec![3.0,4.0]]; let mut r_m1 = &mut m1; let rr_m1 = &mut r_m1; let mut m2: Vec<Vec<f64>> = vec![vec![1.0, 2.0, 3.0, 4.0], vec![4.0, 5.0, 6.0, 7.0], vec![7.0, 8.0, 9.0, 10.0], vec![10.0, 11.0, 12.0, 13.0]]; let mut r_m2 = &mut m2; let rr_m2...
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#Scala
Scala
  def permutationsSgn[T]: List[T] => List[(Int,List[T])] = { case Nil => List((1,Nil)) case xs => { for { (x, i) <- xs.zipWithIndex (sgn,ys) <- permutationsSgn(xs.take(i) ++ xs.drop(1 + i)) } yield { val sgni = sgn * (2 * (i%2) - 1) (sgni, (x :: ys)) } } }   def det(m:List[List...
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Maple
Maple
1/0; # Here is the default behavior.
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
Check[2/0, Print["division by 0"], Power::infy]
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#MATLAB
MATLAB
function [isDividedByZero] = dividebyzero(numerator, denomenator) isDividedByZero = isinf( numerator/denomenator ); % If isDividedByZero equals 1, divide by zero occured.
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#i
i
concept numeric(n) { number(n) errors { print(n, " is not numeric!") return } print(n, " is numeric :)") }   software { numeric("1200") numeric("3.14") numeric("3/4") numeric("abcdefg") numeric("1234test") }
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#Icon_and_Unicon
Icon and Unicon
  write(image(x), if numeric(x) then " is numeric." else " is not numeric")  
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being ...
#R
R
isAllUnique <- function(string) { strLength <- nchar(string) if(length(strLength) > 1) { #R has a distinction between the length of a string and that of a character vector. It is a common source #of problems when coming from another language. We will try to avoid the topic here. #For our purposes, let...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#REXX
REXX
/*REXX program verifies that all characters in a string are all the same (character). */ @chr= ' [character' /* define a literal used for SAY.*/ @all= 'all the same character for string (length' /* " " " " " " */ @.= ...
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou...
#Tcl
Tcl
package require Thread   foreach name {Aristotle Kant Spinoza Marx Russel} { lappend forks [thread::mutex create] lappend tasks [set t [thread::create -preserved { # Implement each task as a coroutine internally for simplicity of presentation # This is because we want to remain able to receive m...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Scala
Scala
package rosetta   import java.util.GregorianCalendar import java.util.Calendar   object DDate extends App { private val DISCORDIAN_SEASONS = Array("Chaos", "Discord", "Confusion", "Bureaucracy", "The Aftermath")   // month from 1-12; day from 1-31 def ddate(year: Int, month: Int, day: Int): String = { val dat...
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro...
#Swift
Swift
typealias WeightedEdge = (Int, Int, Int)   struct Grid<T> { var nodes: [Node<T>]   mutating func addNode(data: T) -> Int { nodes.append(Node(data: data, edges: []))   return nodes.count - 1 }   mutating func createEdges(weights: [WeightedEdge]) { for (start, end, weight) in weights { nodes[sta...
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displ...
#Prolog
Prolog
digit_sum(N, Base, Sum):- digit_sum(N, Base, Sum, 0).   digit_sum(N, Base, Sum, S1):- N < Base, !, Sum is S1 + N. digit_sum(N, Base, Sum, S1):- divmod(N, Base, M, Digit), S2 is S1 + Digit, digit_sum(M, Base, Sum, S2).   digital_root(N, Base, AP, DR):- digital_root(N, Base, AP, DR, 0).   ...
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of...
#Wren
Wren
import "/seq" for Lst   var permute // recursive permute = Fn.new { |input| if (input.count == 1) return [input] var perms = [] var toInsert = input[0] for (perm in permute.call(input.skip(1).toList)) { for (i in 0..perm.count) { var newPerm = perm.toList newPerm.insert(i...
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot ...
#MUMPS
MUMPS
DOTPROD(A,B)  ;Returns the dot product of two vectors. Vectors are assumed to be stored as caret-delimited strings of numbers.  ;If the vectors are not of equal length, a null string is returned. QUIT:$LENGTH(A,"^")'=$LENGTH(B,"^") "" NEW I,SUM SET SUM=0 FOR I=1:1:$LENGTH(A,"^") SET SUM=SUM+($PIECE(A,"^",I)*$PIECE(...
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot ...
#Nemerle
Nemerle
using System; using System.Console; using Nemerle.Collections.NCollectionsExtensions;   module DotProduct { DotProduct(x : array[int], y : array[int]) : int { $[(a * b)|(a, b) in ZipLazy(x, y)].FoldLeft(0, _+_); }   Main() : void { def arr1 = array[1, 3, -5]; def arr2 = array[4, ...
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and mu...
#Fortran
Fortran
INTEGER P,S,F !Department codes for Police, Sanitation, and Fire. Values 1 to 7 only. 1 PP:DO P = 2,7,2 !The police demand an even number. They're special and use violence. 2 SS:DO S = 1,7 !The sanitation department accepts any value. 3 IF (P.EQ.S) CYCLE SS !But it must differ from the othe...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Rust
Rust
trait Thingable { fn thing(&self) -> &str; }   struct Delegator<T>(Option<T>);   struct Delegate {}   impl Thingable for Delegate { fn thing(&self) -> &'static str { "Delegate implementation" } }   impl<T: Thingable> Thingable for Delegator<T> { fn thing(&self) -> &str { self.0.as_ref()....
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Scala
Scala
trait Thingable { def thing: String }   class Delegator { var delegate: Thingable = _   def operation: String = if (delegate == null) "default implementation" else delegate.thing }   class Delegate extends Thingable { override def thing = "delegate implementation" }   // Example usage // Memory management ign...
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)...
#REXX
REXX
/* REXX */ Signal On Halt Signal On Novalue Signal On Syntax   fid='trio.in' oid='trio.txt'; 'erase' oid     Call trio_test '0 0 5 0 0 5 0 0 5 0 0 6' Call trio_test '0 0 0 5 5 0 0 0 0 5 5 0' Call trio_test '0 0 5 0 0 5 -10 0 -5 0 -1 6' Call trio_test '0 0 5 0 2.5 5 0 4 2.5 -1 5 4' Cal...
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Lasso
Lasso
// delete file local(f = file('input.txt')) #f->delete   // delete directory // directory must be empty before it can be successfully deleted. A failure is generated if the operation fails. local(d = dir('docs')) #d->delete   // delete file in root file system (requires permissions at user OS level) local(f = file('//i...
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Liberty_BASIC
Liberty BASIC
' show where we are print DefaultDir$   ' in here kill "input.txt" result=rmdir("Docs")   ' from root kill "\input.txt" result=rmdir("\Docs")  
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#Sidef
Sidef
class Array { method permanent { var r = @^self.len   var sum = 0 r.permutations { |*a| var prod = 1 [a,r].zip {|row,col| prod *= self[row][col] } sum += prod }   return sum } }   var m1 = [[1,2],[3,4]]   var m2 = [[1, 2, 3, 4], ...
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Maxima
Maxima
f(a, b) := block([q: errcatch(a / b)], if emptyp(q) then 'error else q[1]);   f(5, 6); 5 / 6   f(5, 0;) 'error
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#MAXScript
MAXScript
if not bit.isFinite (<i>expression</i>) then...
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#min
min
(/ inf ==) :div-zero?
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#IDL
IDL
function isnumeric,input on_ioerror, false test = double(input) return, 1 false: return, 0 end
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#J
J
isNumeric=: _ ~: _ ". ] isNumericScalar=: 1 -: isNumeric TXT=: ,&' a scalar numeric value.' &.> ' is not';' represents' sayIsNumericScalar=: , TXT {::~ isNumericScalar
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being ...
#Racket
Racket
#lang racket   (define (first-non-unique-element.index seq) (let/ec ret (for/fold ((es (hash))) ((e seq) (i (in-naturals))) (if (hash-has-key? es e) (ret (list e (hash-ref es e) i)) (hash-set es e i))) #f))   (define (report-if-a-string-has-all-unique-characters str) (printf "~s (length ~a): ~a~%" str...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being ...
#Raku
Raku
-> $str { my $i = 0; print "\n{$str.raku} (length: {$str.chars}), has "; my %m; %m{$_}.push: ++$i for $str.comb; if any(%m.values) > 1 { say "duplicated characters:"; say "'{.key}' ({.key.uninames}; hex ordinal: {(.key.ords).fmt: "0x%X"})" ~ " in positions: {.value.join: ',...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#Ring
Ring
  nputStr = [""," ","2","333",".55","tttTTT","4444 444k"]   for word in inputStr for x = 1 to len(word) for y = x + 1 to len(word) if word[x] != word[y] char = word[y]  ? "Input = " + "'" + word + "'" + ", length = " + len(word)  ? " First difference ...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#Ruby
Ruby
strings = ["", " ", "2", "333", ".55", "tttTTT", "4444 444k", "pépé", "🐶🐶🐺🐶", "🎄🎄🎄🎄"]   strings.each do |str| pos = str.empty? ? nil : str =~ /[^#{str[0]}]/ print "#{str.inspect} (size #{str.size}): " puts pos ? "first different char #{str[pos].inspect} (#{'%#x' % str[pos].ord}) at position #{pos}." ...
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou...
#VBA
VBA
'The combination of holding to the second fork '(HOLDON=True) and all philosophers start 'with same hand (DIJKSTRASOLUTION=False) leads 'to a deadlock. To prevent deadlock 'set HOLDON=False, and DIJKSTRASOLUTION=True. Public Const HOLDON = False Public Const DIJKSTRASOLUTION = True Public Const X = 10 'chance to contin...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Seed7
Seed7
$ include "seed7_05.s7i"; include "time.s7i";   const array string: seasons is [0] ("Chaos", "Discord", "Confusion", "Bureaucracy", "The Aftermath"); const array string: weekday is [0] ("Sweetmorn", "Boomtime", "Pungenday", "Prickle-Prickle", "Setting Orange"); const array string: apostle is [0] ("Mungday", "Mojoday"...
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro...
#Tailspin
Tailspin
  data vertex <'a'..'f'>, to <vertex>   templates shortestPaths&{graph:} @: []; [ {to: $, distance: 0"1", path:[]} ] -> # when <[](0)> do $@ ! otherwise def closest: $ ... -> ..=Min&{by: :(distance:), select: :()}; $closest -> ..|@: $; def path: [ $closest.path..., $closest.to ]; [ $... -> \(<?(...
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displ...
#PureBasic
PureBasic
; if you just want the DigitalRoot ; Procedure.q DigitalRoot(N.q) apparently will do ; i must have missed something because it seems too simple ; http://en.wikipedia.org/wiki/Digital_root#Congruence_formula   Procedure.q DigitalRoot(N.q) Protected M.q=N%9 if M=0:ProcedureReturn 9 Else  :ProcedureReturn M:EndIf EndProc...
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of...
#XPL0
XPL0
include c:\cxpl\codes; int B, C, F, M, S; for B:= 1 to 4 do \Baker does not live on top (5th) floor for C:= 2 to 5 do \Cooper does not live on bottom floor if C#B then \Cooper & Baker live on different floors for F:= 2 to 4 do ...
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot ...
#NetRexx
NetRexx
/* NetRexx */ options replace format comments java crossref savelog symbols binary   whatsTheVectorVictor = [[double 1.0, 3.0, -5.0], [double 4.0, -2.0, -1.0]] dotProduct = Rexx dotProduct(whatsTheVectorVictor) say dotProduct.format(null, 2)   return   method dotProduct(vec1 = double[], vec2 = double[]) public constant...
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and mu...
#FreeBASIC
FreeBASIC
' version 15-08-2017 ' compile with: fbc -s console   Dim As Integer fire, police, sanitation   Print "police fire sanitation" Print "----------------------"   For police = 2 To 7 Step 2 For fire = 1 To 7 If fire = police Then Continue For sanitation = 12 - police - fire If sanitation = fire...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Sidef
Sidef
class NonDelegate { }   class Delegate { method thing { return "delegate implementation" } }   class Delegator (delegate = null) { method operation {   if (delegate.respond_to(:thing)) { return delegate.thing }   return "default implementation" } }   var d = D...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Smalltalk
Smalltalk
Object subclass:#Thingy instanceVariableNames:''   thing ^ 'thingy implementation'
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Swift
Swift
import Foundation   protocol Thingable { // prior to Swift 1.2, needs to be declared @objc func thing() -> String }   class Delegator { weak var delegate: AnyObject? func operation() -> String { if let f = self.delegate?.thing { return f() } else { return "default implementation" } } }  ...
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)...
#Ruby
Ruby
require "matrix"   def det2D(p1, p2, p3) return p1[0] * (p2[1] - p3[1]) + p2[0] * (p3[1] - p1[1]) + p3[0] * (p1[1] - p2[1]) end   def checkTriWinding(p1, p2, p3, allowReversed) detTri = det2D(p1, p2, p3) if detTri < 0.0 then if allowReversed then p2[0], p3[0] = p3[0], p2[0] p...
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Lingo
Lingo
-- note: fileIO xtra is shipped with Director, i.e. an "internal" fp = xtra("fileIO").new() fp.openFile("input.txt", 0) fp.delete()
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Locomotive_Basic
Locomotive Basic
|era,"input.txt"
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#Simula
Simula
! MATRIX ARITHMETIC ; BEGIN   INTEGER PROCEDURE LENGTH(A); ARRAY A; LENGTH := UPPERBOUND(A, 1) - LOWERBOUND(A, 1) + 1;    ! Set MAT to the first minor of A dropping row X and column Y ; PROCEDURE MINOR(A, X, Y, MAT); ARRAY A, MAT; INTEGER X, Y; BEGIN INTEGER I, J, rowA, M; M := LENGTH(A) ...
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#SPAD
SPAD
(1) -> M:=matrix [[2, 9, 4], [7, 5, 3], [6, 1, 8]]   +2 9 4+ | | (1) |7 5 3| | | +6 1 8+ Type: Matrix(Integer) (2) -> determinant M   (2) - 360 ...
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#mIRC_Scripting_Language
mIRC Scripting Language
var %n = $rand(0,1) if ($calc(1/ %n) == $calc((1/ %n)+1)) { echo -ag Divides By Zero } else { echo -ag Does Not Divide By Zero }
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#MUMPS
MUMPS
DIV(A,B) ;Divide A by B, and watch for division by zero  ;The ANSI error code for division by zero is "M9".  ;$ECODE errors are surrounded by commas when set. NEW $ETRAP SET $ETRAP="GOTO DIVFIX^ROSETTA" SET D=(A/B) SET $ETRAP="" QUIT D DIVFIX IF $FIND($ECODE,",M9,")>1 WRITE !,"Error: Division by zero" SET $ECODE=...
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#Java
Java
public boolean isNumeric(String input) { try { Integer.parseInt(input); return true; } catch (NumberFormatException e) { // s is not numeric return false; } }
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric
Determine if a string is numeric
Task Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings. Other tasks related to string operations: Metrics Array length String length Cop...
#JavaScript
JavaScript
function isNumeric(n) { return !isNaN(parseFloat(n)) && isFinite(n); } var value = "123.45e7"; // Assign string literal to value if (isNumeric(value)) { // value is a number } //Or, in web browser in address field: // javascript:function isNumeric(n) {return !isNaN(parseFloat(n)) && isFinite(n);}; value="123.45e4"...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters
Determine if a string has all unique characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are unique   indicate if or which character is duplicated and where   display each string and its length   (as the strings are being ...
#REXX
REXX
/*REXX pgm determines if a string is comprised of all unique characters (no duplicates).*/ @.= /*assign a default for the @. array. */ parse arg @.1 /*obtain optional argument from the CL.*/ if @.1='' then do; @.1= ...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#Rust
Rust
fn test_string(input: &str) { println!("Checking string {:?} of length {}:", input, input.chars().count());   let mut chars = input.chars();   match chars.next() { Some(first) => { if let Some((character, pos)) = chars.zip(2..).filter(|(c, _)| *c != first).next() { printl...
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters
Determine if a string has all the same characters
Task Given a character string   (which may be empty, or have a length of zero characters):   create a function/procedure/routine to:   determine if all the characters in the string are the same   indicate if or which character is different from the previous character   display each string and its length   (as the...
#Scala
Scala
import scala.collection.immutable.ListMap   object StringAllSameCharacters {   /**Transform an input String into an HashMap of its characters and its first occurrence index*/ def countChar( s : String) : Map[Char, Int] = { val mapChar = s.toSeq.groupBy(identity).map{ case (a,b) => a->s.indexOf(a) } val orde...
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou...
#Visual_Basic_.NET
Visual Basic .NET
Imports System.Threading Module Module1 Public rnd As New Random   Sub Main() 'Aristotle, Kant, Spinoza, Marx, and Russel Dim f1 As New Fork(1) Dim f2 As New Fork(2) Dim f3 As New Fork(3) Dim f4 As New Fork(4) Dim f5 As New Fork(5)   Console.WriteLine("1: Deadlock...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Sidef
Sidef
require('Time::Piece');   var seasons = %w(Chaos Discord Confusion Bureaucracy The\ Aftermath); var week_days = %w(Sweetmorn Boomtime Pungenday Prickle-Prickle Setting\ Orange);   func ordinal (n) { "#{n}" + (n % 100 ~~ [11,12,13] ? 'th'  : <th st nd rd th th th th th th>[n % 10])...
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro...
#Tcl
Tcl
proc dijkstra {graph origin} { # Initialize dict for {vertex distmap} $graph { dict set dist $vertex Inf dict set path $vertex {} } dict set dist $origin 0 dict set path $origin [list $origin]   while {[dict size $graph]} { # Find unhandled node with least weight set d Inf dict for {uu -} $...
http://rosettacode.org/wiki/Digital_root
Digital root
The digital root, X {\displaystyle X} , of a number, n {\displaystyle n} , is calculated: find X {\displaystyle X} as the sum of the digits of n {\displaystyle n} find a new X {\displaystyle X} by summing the digits of X {\displaystyle X} , repeating until X {\displ...
#Python
Python
def digital_root (n): ap = 0 n = abs(int(n)) while n >= 10: n = sum(int(digit) for digit in str(n)) ap += 1 return ap, n   if __name__ == '__main__': for n in [627615, 39390, 588225, 393900588225, 55]: persistance, root = digital_root(n) print("%12i has additive persi...
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem
Dinesman's multiple-dwelling problem
Task Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below. Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of...
#zkl
zkl
var Baker, Cooper, Fletcher, Miller, Smith; // value == floor const bottom=1,top=5; // floors: 1..5 // All live on different floors, enforced by using permutations of floors //fcn c0{ (Baker!=Cooper!=Fletcher) and (Fletcher!=Miller!=Smith) } fcn c1{ Baker!=top } fcn c2{ Cooper!=bottom } fcn c3{ bottom!=Fletcher!=top }...
http://rosettacode.org/wiki/Dot_product
Dot product
Task Create a function/use an in-built function, to compute the   dot product,   also known as the   scalar product   of two vectors. If possible, make the vectors of arbitrary length. As an example, compute the dot product of the vectors:   [1,  3, -5]     and   [4, -2, -1] If implementing the dot ...
#newLISP
newLISP
(define (dot-product x y) (apply + (map * x y)))   (println (dot-product '(1 3 -5) '(4 -2 -1)))
http://rosettacode.org/wiki/Department_numbers
Department numbers
There is a highly organized city that has decided to assign a number to each of their departments:   police department   sanitation department   fire department Each department can have a number between   1   and   7   (inclusive). The three department numbers are to be unique (different from each other) and mu...
#Gambas
Gambas
Public Sub Main() Dim siC0, siC1, siC2 As Short Dim sOut As New String[] Dim sTemp As String   For siC0 = 2 To 6 Step 2 For siC1 = 1 To 7 For siC2 = 1 To 7 If sic0 + siC1 + siC2 = 12 Then If siC0 <> siC1 And siC1 <> siC2 And siC0 <> siC2 Then sOut.Add(Str(siC0) & Str(siC1) & Str(siC2)) End If ...
http://rosettacode.org/wiki/Delegates
Delegates
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern. Objects ...
#Tcl
Tcl
package require TclOO   oo::class create Delegate { method thing {} { return "delegate impl." } export thing }   oo::class create Delegator { variable delegate constructor args { my delegate {*}$args }   method delegate args { if {[llength $args] == 0} { i...
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap
Determine if two triangles overlap
Determining if two triangles in the same plane overlap is an important topic in collision detection. Task Determine which of these pairs of triangles overlap in 2D:   (0,0),(5,0),(0,5)     and   (0,0),(5,0),(0,6)   (0,0),(0,5),(5,0)     and   (0,0),(0,5),(5,0)   (0,0),(5,0),(0,5)     and   (-10,0),(-5,0),(-1,6)...
#Scala
Scala
object Overlap { type Point = (Double, Double)   class Triangle(var p1: Point, var p2: Point, var p3: Point) { override def toString: String = s"Triangle: $p1, $p2, $p3" }   def det2D(t: Triangle): Double = { val (p1, p2, p3) = (t.p1, t.p2, t.p3) p1._1 * (p2._2 - p3._2) + p2._1 * (p3._2 - p1._...
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Logo
Logo
erasefile "input.txt erasefile "/input.txt
http://rosettacode.org/wiki/Delete_a_file
Delete a file
Task Delete a file called "input.txt" and delete a directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
#Lua
Lua
os.remove("input.txt") os.remove("/input.txt") os.remove("docs") os.remove("/docs")
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#Stata
Stata
real vector range1(real scalar n, real scalar i) { if (i < 1 | i > n) { return(1::n) } else if (i == 1) { return(2::n) } else if (i == n) { return(1::n-1) } else { return(1::i-1\i+1::n) } }   real matrix submat(real matrix a, real scalar i, real scalar j) { return(a[range1(rows(a), i), range1(cols(a), j)]...
http://rosettacode.org/wiki/Determinant_and_permanent
Determinant and permanent
For a given matrix, return the determinant and the permanent of the matrix. The determinant is given by det ( A ) = ∑ σ sgn ⁡ ( σ ) ∏ i = 1 n M i , σ i {\displaystyle \det(A)=\sum _{\sigma }\operatorname {sgn}(\sigma )\prod _{i=1}^{n}M_{i,\sigma _{i}}} while the permanent is given by ...
#Tcl
Tcl
package require math::linearalgebra package require struct::list   proc permanent {matrix} { for {set plist {};set i 0} {$i<[llength $matrix]} {incr i} { lappend plist $i } foreach p [::struct::list permutations $plist] { foreach i $plist j $p { lappend prod [lindex $matrix $i $j] } lappend sum [::...
http://rosettacode.org/wiki/Detect_division_by_zero
Detect division by zero
Task Write a function to detect a   divide by zero error   without checking if the denominator is zero.
#Nanoquery
Nanoquery
def div_check(x, y) try (x / y) return false catch return true end end