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http://rosettacode.org/wiki/Deming%27s_Funnel
Deming's Funnel
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ...
#Stretch_2
Stretch 2
  ListPlot[MarblePositions[#][Transpose[{dxs,dys}]]&/@Range[4],PlotLegends->PointLegend[{1,2,3,4}],AspectRatio->Automatic,ImageSize->600]  
http://rosettacode.org/wiki/Deming%27s_Funnel
Deming's Funnel
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ...
#Nim
Nim
import stats, strformat   type Rule = proc(x, y: float): float   const Dxs = [-0.533, 0.270, 0.859, -0.043, -0.205, -0.127, -0.071, 0.275, 1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.150, 0.001, -0.382, 0.161, 0.915, 2.080, -2.337, 0.034, -0.126, 0.014, 0.709, 0....
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...
#Arturo
Arturo
loop 1..7 'x [ loop 1..7 'y [ loop 1..7 'z [ if all? @[ even? x 12 = sum @[x y z] 3 = size unique @[x y z] ] -> print [x y z] ] ] ]
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 ...
#Dart
Dart
class Delegator { var delegate;   String operation() { if (delegate == null) return "default implementation"; else return delegate.thing(); } }   class Delegate { String thing() => "delegate implementation"; }   main() { // Without a delegate: Delegator a = new Delegator(); Expect.equa...
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 ...
#Delphi
Delphi
unit Printer;   interface   type // the "delegate" TRealPrinter = class public procedure Print; end;   // the "delegator" TPrinter = class private FPrinter: TRealPrinter; public constructor Create; destructor Destroy; override; procedure Print; end;   implementation   { TRealPrinte...
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)...
#Java
Java
import java.util.function.BiFunction;   public class TriangleOverlap { private static class Pair { double first; double second;   Pair(double first, double second) { this.first = first; this.second = second; }   @Override public String toString...
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.
#C.2B.2B
C++
#include <cstdio> #include <direct.h>   int main() { remove( "input.txt" ); remove( "/input.txt" ); _rmdir( "docs" ); _rmdir( "/docs" );   return 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.
#Clojure
Clojure
(import '(java.io File)) (.delete (File. "output.txt")) (.delete (File. "docs"))   (.delete (new File (str (File/separator) "output.txt"))) (.delete (new File (str (File/separator) "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 ...
#J
J
i. 5 5 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
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 ...
#Java
Java
import java.util.Scanner;   public class MatrixArithmetic { public static double[][] minor(double[][] a, int x, int y){ int length = a.length-1; double[][] result = new double[length][length]; for(int i=0;i<length;i++) for(int j=0;j<length;j++){ if(i<x && j<y){ result[i][j] = a[i][j]; }else if(i>=x && ...
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.
#Eiffel
Eiffel
class MAIN creation main feature main is local x, y: INTEGER; retried: BOOLEAN; do x := 42; y := 0;   if not retried then io.put_real(x / y); else print("NaN%N"); end rescu...
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.
#Ela
Ela
open core number   x /. y = try Some (x `div` y) with _ = None   (12 /. 2, 12 /. 0)
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...
#COBOL
COBOL
program-id. is-numeric. procedure division. display function test-numval-f("abc") end-display display function test-numval-f("-123.01E+3") end-display if function test-numval-f("+123.123") equal zero then display "is numeric" end-display else displ...
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...
#CoffeeScript
CoffeeScript
  console.log (isFinite(s) for s in [5, "5", "-5", "5", "5e5", 0]) # all true console.log (isFinite(s) for s in [NaN, "fred", "###"]) # all false  
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 ...
#Factor
Factor
USING: formatting fry generalizations io kernel math.parser sequences sets ;   : repeated ( elt seq -- ) [ dup >hex over ] dip indices first2 " '%c' (0x%s) at indices %d and %d.\n" printf ;   : uniqueness-report ( str -- ) dup dup length "%u — length %d — contains " printf [ duplicates ] keep over empt...
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 ...
#Fortran
Fortran
  program demo_verify implicit none call nodup('') call nodup('.') call nodup('abcABC') call nodup('XYZ ZYX') call nodup('1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ') contains   subroutine nodup(str) character(len=*),intent(in)  :: str character(len=*),parameter  :: g='(*(g0))' character(len=:),allocatab...
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...
#Ksh
Ksh
  #!/bin/ksh   # Determine if a string is collapsible (repeated letters)   # # Variables: # typeset -a strings strings[0]="" strings[1]='"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln' strings[2]="..1111111111111111111111111111111111111111111111111111111111111117777888" strings[3]="I never ...
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...
#Lua
Lua
function collapse(s) local ns = "" local last = nil for c in s:gmatch"." do if last then if last ~= c then ns = ns .. c end last = c else ns = ns .. c last = c end end return ns end   function test(s)...
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...
#J
J
  Doc=: 2 : 'u :: (n"_)'   task=: monad define common=. (; #) y NB. the string and its length if. same y do. common , <'same' else. i =. differ y c =. i { y common , <((, (' (' , ') ' ,~ hex))c),'differs at index ',":i end. )   hex=: ((Num_j_,26}.Alpha_j_) {~ 16 16 #: a.&i.)&> Doc 'convert ASCII literals t...
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...
#Java
Java
public class Main{ public static void main(String[] args){ String[] tests = {"", " ", "2", "333", ".55", "tttTTT", "4444 444k"}; for(String s:tests) analyze(s); }   public static void analyze(String s){ System.out.printf("Examining [%s] which has a length of %d:\n", s, s.length()); if(s.length() > 1){ ...
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...
#Oz
Oz
declare Philosophers = [aristotle kant spinoza marx russell]   proc {Start} Forks = {MakeList {Length Philosophers}} in {ForAll Forks NewFork} for Name in Philosophers LeftFork in Forks RightFork in {RightShift Forks} do thread {Philosopher Name LeftF...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Pascal
Pascal
  program ddate; { This program is free software, it's done it's time and paid for it's crime. You can copy, edit and use this software under the terms of the GNU GPL v3 or later.   Copyright Pope Englebert Finklestien, On this day Boomtime, the 71st day of Confusion in the YOLD 3183   This program will print out the c...
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...
#Pascal
Pascal
program dijkstra(output);   type { We dynamically build the list of vertices from the edge list, just to avoid repeating ourselves in the graph input. Vertices are linked together via their `next` pointers to form a list of all vertices (sorted by name), while the `previous` pointer indicates the previous...
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...
#JavaScript
JavaScript
/// Digital root of 'x' in base 'b'. /// @return {addpers, digrt} function digitalRootBase(x,b) { if (x < b) return {addpers:0, digrt:x};   var fauxroot = 0; while (b <= x) { x = (x / b) | 0; fauxroot += x % b; }   var rootobj = digitalRootBase(fauxroot,b); rootobj.addpers += 1; r...
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root
Digital root/Multiplicative digital root
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number, n {\displaystyle n} , is calculated rather like the Digital root except digits are multiplied instead of being added: Set m {\displaystyle m} to n {\displaystyle n} and i {\displaystyle i} to 0 ...
#Tcl
Tcl
proc mdr {n} { if {$n < 0 || ![string is integer $n]} { error "must be an integer" } for {set i 0} {$n > 9} {incr i} { set n [tcl::mathop::* {*}[split $n ""]] } return [list $i $n] }
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...
#PicoLisp
PicoLisp
# Problem statement (be dwelling (@Tenants) (permute (Baker Cooper Fletcher Miller Smith) @Tenants) (not (topFloor Baker @Tenants)) (not (bottomFloor Cooper @Tenants)) (not (or ((topFloor Fletcher @Tenants)) ((bottomFloor Fletcher @Tenants)))) (higherFloor Miller Cooper @Tenants) (not (adjacentFloor S...
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 ...
#IDL
IDL
  a = [1, 3, -5] b = [4, -2, -1] c = a#TRANSPOSE(b) c = TOTAL(a*b,/PRESERVE_TYPE)  
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead...
#MATLAB_.2F_Octave
MATLAB / Octave
  function r = squeezee(s,c) ix = []; c = unique(c); for k=1:length(c) ix=[ix; find((s(1:end-1)==s(2:end)) & (s(1:end-1)==c(k)))+1]; end r=s; r(ix)=[];   fprintf(1,'Character to be squeezed: "%s"\n',c); fprintf(1,'Input: <<<%s>>> length: %d\n',s,length(s)); fprintf(1,'Output: <<<%s>>> len...
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead...
#NetLogo
NetLogo
  to-report split [ string ]  ;; utility reporter to split a string into a list report n-values length string [ [ n ] -> item n string ] end   to-report squeeze [ character string ]  ;; reporter that actually does the squeeze function  ;; remote immeadiately repeating instances of character from string ifelse ...
http://rosettacode.org/wiki/Deming%27s_Funnel
Deming's Funnel
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ...
#PARI.2FGP
PARI/GP
drop(drops, rule, rnd)={ my(v=vector(drops),target=0); v[1]=rule(target, 0); for(i=2,drops, target=rule(target, v[i-1]); v[i]=rnd(n)+target ); v }; R=[-.533-.136*I,.27-.717*I,.859-.459*I,-.043+.225*I,-.205-1.39*I,-.127-.385*I,-.071-.121*I,.275+.395*I,1.25-.490*I,-.231+.682*I,-.401+.0650*I,.269-.242*I,...
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...
#Asymptote
Asymptote
write("--police-- --sanitation-- --fire--");   for(int police = 2; police < 6; police += 2) { for(int sanitation = 1; sanitation < 7; ++sanitation) { for(int fire = 1; fire < 7; ++fire) { if(police != sanitation && sanitation != fire && fire != police && police+fire+sanitation == 12){ write(" "...
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 ...
#E
E
def makeDelegator { /** construct without an explicit delegate */ to run() { return makeDelegator(null) }   /** construct with a delegate */ to run(delegateO) { # suffix because "delegate" is a reserved keyword def delegator { to operation() { return if (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 ...
#Elena
Elena
import extensions; import system'routines;   interface IOperable { abstract operate() {} }   class Operable : IOperable { constructor() {}   operate() = "delegate implementation"; }   class Delegator { object theDelegate;   set Delegate(object) { theDelegate := object }   ...
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)...
#jq
jq
# Points are realized as arrays of two numbers [x, y]   # Triangles are realized as triples of Points [p1, p2, p3]   # Input: a Triangle def det2D: . as [ [$p1x, $p1y], [$p2x, $p2y], [$p3x, $p3y]] | $p1x * ($p2y - $p3y) + $p2x * ($p3y - $p1y) + $p3x * ($p1y - $p2y) ;   # Input: a Triangle def checkTriWi...
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.
#COBOL
COBOL
IDENTIFICATION DIVISION. PROGRAM-ID. Delete-Files.   PROCEDURE DIVISION. CALL "CBL_DELETE_FILE" USING "input.txt" CALL "CBL_DELETE_DIR" USING "docs" CALL "CBL_DELETE_FILE" USING "/input.txt" CALL "CBL_DELETE_DIR" USING "/docs"   GOBACK ...
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.
#Common_Lisp
Common Lisp
(delete-file (make-pathname :name "input.txt")) (delete-file (make-pathname :directory '(:absolute "") :name "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 ...
#JavaScript
JavaScript
const determinant = arr => arr.length === 1 ? ( arr[0][0] ) : arr[0].reduce( (sum, v, i) => sum + v * (-1) ** i * determinant( arr.slice(1) .map(x => x.filter((_, j) => i !== j)) ), 0 );   const permanent = arr => arr.length === 1 ? ( arr[0][0] ...
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.
#Elixir
Elixir
defmodule Division do def by_zero?(x,y) do try do _ = x / y false rescue ArithmeticError -> true end end end   [{2, 3}, {3, 0}, {0, 5}, {0, 0}, {2.0, 3.0}, {3.0, 0.0}, {0.0, 5.0}, {0.0, 0.0}] |> Enum.each(fn {x,y} -> IO.puts "#{x} / #{y}\tdivision by zero #{Division.by_zero?(x,y)}" ...
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.
#Emacs_Lisp
Emacs Lisp
(condition-case nil (/ 1 0) (arith-error (message "Divide by zero (either integer or float)")))
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.
#Erlang
Erlang
div_check(X,Y) -> case catch X/Y of {'EXIT',_} -> true; _ -> false 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...
#ColdFusion
ColdFusion
<cfset TestValue=34> TestValue: <cfoutput>#TestValue#</cfoutput><br> <cfif isNumeric(TestValue)> is Numeric. <cfelse> is NOT Numeric. </cfif>   <cfset TestValue="NAS"> TestValue: <cfoutput>#TestValue#</cfoutput><br> <cfif isNumeric(TestValue)> is Numeric. <cfelse> is NOT Numeric. </cfif>
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 ...
#FreeBASIC
FreeBASIC
Sub CaracteresUnicos (cad As String) Dim As Integer lngt = Len(cad) Print "Cadena = """; cad; """, longitud = "; lngt For i As Integer = 1 To lngt For j As Integer = i + 1 To lngt If Mid(cad,i,1) = Mid(cad,j,1) Then Print " Primer duplicado en las posiciones " & i & _ ...
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...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
ClearAll[StringCollapse] StringCollapse[s_String] := FixedPoint[StringReplace[y_ ~~ y_ :> y], s] strings = {"", "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln ", "..1111111111111111111111111111111111111111111111111111111111111117777888", "I never give 'em hell, I just tell the truth, and t...
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...
#MATLAB_.2F_Octave
MATLAB / Octave
  function r = collapse(s) ix=find((s(1:end-1)==s(2:end))+1; r=s; r(ix)=[];   fprintf(1,'Input: <<<%s>>> length: %d\n',s,length(s)); fprintf(1,'Output: <<<%s>>> length: %d\n',r,length(r)); fprintf(1,'Character to be squeezed: "%s"\n',c);   end     collapse('', ' ') collapse('║╚════════════════════...
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...
#JavaScript
JavaScript
const check = s => { const arr = [...s]; const at = arr.findIndex( (v, i) => i === 0 ? false : v !== arr[i - 1] ) const l = arr.length; const ok = at === -1; const p = ok ? "" : at + 1; const v = ok ? "" : arr[at]; const vs = v === "" ? v : `"${v}"` const h = ok ? "" : `0x${v.codePointAt(0).toSt...
http://rosettacode.org/wiki/Dining_philosophers
Dining philosophers
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra. Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou...
#Pascal
Pascal
  program dining_philosophers; {$mode objfpc}{$H+} uses {$IFDEF UNIX} cthreads, {$ENDIF} Classes, SysUtils, SyncObjs; const PHIL_COUNT = 5; LIFESPAN = 7; DELAY_RANGE = 950; DELAY_LOW = 50; PHIL_NAMES: array[1..PHIL_COUNT] of string = ('Aristotle', 'Kant', 'Spinoza', 'Marx', 'Russell'); type ...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Perl
Perl
use 5.010; use strict; use warnings; use Time::Piece ();   my @seasons = (qw< Chaos Discord Confusion Bureaucracy >, 'The Aftermath'); my @week_days = (qw< Sweetmorn Boomtime Pungenday Prickle-Prickle >, 'Setting Orange');   sub ordinal { my ($n) = @_; return $n . "th" if int($n/10) == 1; return $n . ((qw< th st nd ...
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro...
#Perl
Perl
use strict; use warnings; use constant True => 1;   sub add_edge { my ($g, $a, $b, $weight) = @_; $g->{$a} ||= {name => $a}; $g->{$b} ||= {name => $b}; push @{$g->{$a}{edges}}, {weight => $weight, vertex => $g->{$b}}; }   sub push_priority { my ($a, $v) = @_; my $i = 0; my $j = $#{$a}; w...
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...
#jq
jq
def do_until(condition; next): def u: if condition then . else (next|u) end; u;   # n may be a decimal number or a string representing a decimal number def digital_root(n): # string-only version def dr: # state: [mdr, persist] do_until( .[0] | length == 1; [ (.[0] | explode | map(.-48) | a...
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...
#Julia
Julia
function digitalroot(n::Integer, bs::Integer=10) if n < 0 || bs < 2 throw(DomainError()) end ds, pers = n, 0 while bs ≤ ds ds = sum(digits(ds, bs)) pers += 1 end return pers, ds end   for i in [627615, 39390, 588225, 393900588225, big(2) ^ 100] pers, ds = digitalroot(i) print...
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root
Digital root/Multiplicative digital root
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number, n {\displaystyle n} , is calculated rather like the Digital root except digits are multiplied instead of being added: Set m {\displaystyle m} to n {\displaystyle n} and i {\displaystyle i} to 0 ...
#Vlang
Vlang
// Only valid for n > 0 && base >= 2 fn mult(nn u64, base int) u64 { mut n := nn mut mult := u64(0) for mult = 1; mult > 0 && n > 0; n /= u64(base) { mult *= n % u64(base) } return mult }   // Only valid for n >= 0 && base >= 2 fn multi_digital_root(n u64, base int) (int, int) { mut m := u64(0) mut mp := 0 fo...
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root
Digital root/Multiplicative digital root
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number, n {\displaystyle n} , is calculated rather like the Digital root except digits are multiplied instead of being added: Set m {\displaystyle m} to n {\displaystyle n} and i {\displaystyle i} to 0 ...
#Wren
Wren
import "/big" for BigInt import "/fmt" for Fmt   // Only valid for n > 0 && base >= 2 var mult = Fn.new { |n, base| var m = BigInt.one while (m > BigInt.zero && n > BigInt.zero) { var dm = n.divMod(base) m = m * dm[1] n = dm[0] } return m }   // Only valid for n >= 0 && base >= 2...
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...
#PowerShell
PowerShell
  # Floors are numbered 1 (ground) to 5 (top)   # Baker, Cooper, Fletcher, Miller, and Smith live on different floors: $statement1 = '$baker -ne $cooper -and $baker -ne $fletcher -and $baker -ne $miller -and $baker -ne $smith -and $cooper -ne $fletcher -and $cooper -ne $miller -and ...
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 ...
#Idris
Idris
module Main   import Data.Vect   dotProduct : (Num a) => Vect n a -> Vect n a -> a dotProduct = (sum .) . zipWith (*)   main : IO () main = printLn $ dotProduct [1,2,3] [1,2,3]  
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 ...
#J
J
1 3 _5 +/ . * 4 _2 _1 3 dotp=: +/ . * NB. Or defined as a verb (function) 1 3 _5 dotp 4 _2 _1 3
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead...
#Nim
Nim
import unicode, strformat   proc squeeze(s: string; ch: Rune) = echo fmt"Specified character: '{ch}'" let original = s.toRunes echo fmt"Original: length = {original.len}, string = «««{s}»»»" var previous = Rune(0) var squeezed: seq[Rune] for rune in original: if rune != previous: squeezed.add(rune...
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead...
#Perl
Perl
use strict; use warnings; use Unicode::UCD 'charinfo';   for ( ['', ' '], ['"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ', '-'], ['..1111111111111111111111111111111111111111111111111111111111111117777888', '7'], ["I never give 'em hell, I just tell the truth, and they think it's hell...
http://rosettacode.org/wiki/Deming%27s_Funnel
Deming's Funnel
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ...
#Perl
Perl
@dx = qw< -0.533 0.270 0.859 -0.043 -0.205 -0.127 -0.071 0.275 1.251 -0.231 -0.401 0.269 0.491 0.951 1.150 0.001 -0.382 0.161 0.915 2.080 -2.337 0.034 -0.126 0.014 0.709 0.129 -1.093 -0.483 -1.193 0.020 -0.051 0.047 -0.095 0.695 0.340 -0.182 0.287 0.213 -0.423 -0.021 -0.134...
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...
#AutoHotkey
AutoHotkey
perm(elements, n, opt:="", Delim:="", str:="", res:="", j:=0, dup:="") { res := IsObject(res) ? res : [], dup := IsObject(dup) ? dup : [] if (n > j) Loop, parse, elements, % Delim res := !(InStr(str, A_LoopField) && !(InStr(opt, "rep"))) ? perm(elements, n, opt, Delim, trim(str Delim A_LoopField, Delim), res, ...
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 ...
#F.23
F#
type Delegator() = let defaultOperation() = "default implementation" let mutable del = null   // write-only property "Delegate" member x.Delegate with set(d:obj) = del <- d   member x.operation() = if del = null then defaultOperation() else match del.GetType().GetMethod("thing", [||]) with...
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 ...
#Forth
Forth
include FMS-SI.f   :class delegate  :m thing ." delegate implementation" ;m ;class   delegate slave   :class delegator ivar del \ object container  :m !: ( n -- ) del ! ;m  :m init: 0 del ! ;m  :m default ." default implementation" ;m  :m operation del @ 0= if self default exit then del @ has-meth th...
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)...
#Julia
Julia
module Triangles   using LinearAlgebra   export AntiClockwise, Both, StrictCheck, MildCheck   abstract type Widing end struct AntiClockwise <: Widing end struct Both <: Widing end   function _check_triangle_winding(t, widing::AntiClockwise) trisq = fill!(Matrix{eltype(t)}(undef, 3, 3), 1) trisq[:, 1:2]...
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.
#Component_Pascal
Component Pascal
  VAR l: Files.Locator; BEGIN (* Locator is the directory *) l := Files.dir.This("proof"); (* delete 'xx.txt' file, in directory 'proof' *) Files.dir.Delete(l,"xx.txt"); END ...  
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.
#D
D
import std.file: remove;   void main() { remove("data.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 ...
#jq
jq
# Eliminate row i and row j def except(i;j): reduce del(.[i])[] as $row ([]; . + [$row | del(.[j]) ] );   def det: def parity(i): if i % 2 == 0 then 1 else -1 end; if length == 1 and (.[0] | length) == 1 then .[0][0] else . as $m | reduce range(0; length) as $i (0; . + parity($i) * $m[0][$i] * ( $m ...
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 ...
#Julia
Julia
using LinearAlgebra
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.
#ERRE
ERRE
  PROGRAM DIV_BY_ZERO   EXCEPTION IF ERR=11 THEN PRINT("Division by Zero") END IF END EXCEPTION   BEGIN PRINT(0/3) PRINT(3/0) END PROGRAM  
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.
#F.23
F#
let detectDivideZero (x : int) (y : int):int option = try Some(x / y) with | :? System.ArithmeticException -> None     printfn "12 divided by 3 is %A" (detectDivideZero 12 3) printfn "1 divided by 0 is %A" (detectDivideZero 1 0)
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...
#Common_Lisp
Common Lisp
(defun numeric-string-p (string) (let ((*read-eval* nil)) (ignore-errors (numberp (read-from-string string)))))
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...
#D
D
import std.stdio, std.string, std.array;   void main() { foreach (const s; ["12", " 12\t", "hello12", "-12", "02", "0-12", "+12", "1.5", "1,000", "1_000", "0x10", "0b10101111_11110000_11110000_00110011", "-0b10101", "0x10.5"]) writefln(`isNumeric("%s"): %s`...
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 ...
#Go
Go
package main   import "fmt"   func analyze(s string) { chars := []rune(s) le := len(chars) fmt.Printf("Analyzing %q which has a length of %d:\n", s, le) if le > 1 { for i := 0; i < le-1; i++ { for j := i + 1; j < le; j++ { if chars[j] == chars[i] { ...
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...
#Modula-2
Modula-2
MODULE StrCollapse; FROM InOut IMPORT WriteString, WriteCard, WriteLn; FROM Strings IMPORT Length;   (* Collapse a string *) PROCEDURE Collapse(in: ARRAY OF CHAR; VAR out: ARRAY OF CHAR); VAR i, o: CARDINAL; BEGIN i := 0; o := 0; WHILE (i < HIGH(in)) AND (in[i] # CHR(0)) DO IF (o = 0) O...
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...
#jq
jq
jq -rn '   def firstdifferent: label $out | foreach explode[] as $i ({index:-1}; .prev = .i | .i = $i | .index +=1; if .prev and $i != .prev then .index, break $out else empty end) // null ;   def lpad($n): " "*($n-length) + "\"\(.)\"" ;   [" "*10, "length", "same", "index", "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...
#Julia
Julia
firstdifferent(s) = isempty(s) ? nothing : findfirst(x -> x != s[1], s)   function testfunction(strings) println("String | Length | All Same | First Different(Hex) | Position\n" * "-----------------------------------------------------------------------------") for s in strings ...
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...
#Perl
Perl
  use threads; use threads::shared; my @names = qw(Aristotle Kant Spinoza Marx Russell);   my @forks = ('On Table') x @names; share $forks[$_] for 0 .. $#forks;   sub pick_up_forks { my $philosopher = shift; my ($first, $second) = ($philosopher, $philosopher-1); ($first, $second) = ($second, $first) if $philos...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Phix
Phix
with javascript_semantics constant seasons = {"Chaos", "Discord", "Confusion", "Bureaucracy", "The Aftermath"}, weekday = {"Sweetmorn", "Boomtime", "Pungenday", "Prickle-Prickle", "Setting Orange"}, apostle = {"Mungday", "Mojoday", "Syaday", "Zaraday", "Maladay"}, holiday = {"Chaoflux", "Disc...
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...
#Phix
Phix
with javascript_semantics --requires("1.0.2") -- (builtin E renamed as EULER) --enum A,B,C,D,E,F constant A=1, B=2, C=3, D=4, E=5, F=6 -- (or use this) constant edges = {{A,B,7}, {A,C,9}, {A,F,14}, {B,C,10}, {B,D,15}, {C,D,11}, ...
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...
#K
K
  / print digital root and additive persistence prt: {`"Digital root = ", x, `"Additive persistence = ",y} / sum of digits of an integer sumdig: {d::(); (0<){d::d,x!10; x%:10}/x; +/d} / compute digital root and additive persistence digroot: {sm::sumdig x; ap::0; (9<){sm::sumdig x;ap::ap+1; x:sm}/x; prt[sm;ap]}  
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...
#Kotlin
Kotlin
// version 1.0.6   fun sumDigits(n: Long): Int = when { n < 0L -> throw IllegalArgumentException("Negative numbers not allowed") else -> { var sum = 0 var nn = n while (nn > 0L) { sum += (nn % 10).toInt() nn /= 10 } ...
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root
Digital root/Multiplicative digital root
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number, n {\displaystyle n} , is calculated rather like the Digital root except digits are multiplied instead of being added: Set m {\displaystyle m} to n {\displaystyle n} and i {\displaystyle i} to 0 ...
#zkl
zkl
fcn mdroot(n){ // Multiplicative digital root mdr := List(n); while (mdr[-1] > 9){ mdr.append(mdr[-1].split().reduce('*,1)); } return(mdr.len() - 1, mdr[-1]); }
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...
#Prolog
Prolog
:- use_module(library(clpfd)).   :- dynamic top/1, bottom/1.   % Baker does not live on the top floor rule1(L) :- member((baker, F), L), top(Top), F #\= Top.   % Cooper does not live on the bottom floor. rule2(L) :- member((cooper, F), L), bottom(Bottom), F #\= Bottom.   % Fletcher does not live on either the 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 ...
#Java
Java
public class DotProduct {   public static void main(String[] args) { double[] a = {1, 3, -5}; double[] b = {4, -2, -1};   System.out.println(dotProd(a,b)); }   public static double dotProd(double[] a, double[] b){ if(a.length != b.length){ throw new IllegalArgumentException("The dimensions have to be equa...
http://rosettacode.org/wiki/Determine_if_a_string_is_squeezable
Determine if a string is squeezable
Determine if a character string is   squeezable. And if so,   squeeze the string   (by removing any number of a   specified   immediately repeated   character). This task is very similar to the task     Determine if a character string is collapsible     except that only a specified character is   squeezed   instead...
#Phix
Phix
with javascript_semantics constant tests = {"", " ", `"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln `,"-", "..1111111111111111111111111111111111111111111111111111111111111117777888","7",...
http://rosettacode.org/wiki/Deming%27s_Funnel
Deming's Funnel
W Edwards Deming was an American statistician and management guru who used physical demonstrations to illuminate his teachings. In one demonstration Deming repeatedly dropped marbles through a funnel at a target, marking where they landed, and observing the resulting pattern. He applied a sequence of "rules" to try to ...
#Phix
Phix
with javascript_semantics function funnel(sequence dxs, integer rule) atom x = 0.0 sequence rxs = {} for i=1 to length(dxs) do atom dx = dxs[i] rxs = append(rxs,x + dx) switch rule case 2: x = -dx case 3: x = -(x+dx) case 4: x = x+dx end sw...
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...
#AWK
AWK
  # syntax: GAWK -f DEPARTMENT_NUMBERS.AWK BEGIN { print(" # FD PD SD") for (fire=1; fire<=7; fire++) { for (police=1; police<=7; police++) { for (sanitation=1; sanitation<=7; sanitation++) { if (rules() ~ /^1+$/) { printf("%2d %2d %2d %2d\n",++count,fire,police,sanitation) ...
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 ...
#Go
Go
package main import "fmt"   type Delegator struct { delegate interface{} // the delegate may be any type }   // interface that represents anything that supports thing() type Thingable interface { thing() string }   func (self Delegator) operation() string { if v, ok := self.delegate.(Thingable); ok { ...
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 ...
#Io
Io
Delegator := Object clone do( delegate ::= nil operation := method( if((delegate != nil) and (delegate hasSlot("thing")), delegate thing, "default implementation" ) ) )   Delegate := Object clone do( thing := method("delegate implementation") )   a := clone Delega...
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)...
#Kotlin
Kotlin
// version 1.1.0   typealias Point = Pair<Double, Double>   data class Triangle(var p1: Point, var p2: Point, var p3: Point) { override fun toString() = "Triangle: $p1, $p2, $p3" }   fun det2D(t: Triangle): Double { val (p1, p2, p3) = t return p1.first * (p2.second - p3.second) + p2.first * (p3...
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.
#Delphi
Delphi
procedure TMain.btnDeleteClick(Sender: TObject); var CurrentDirectory : String; begin CurrentDirectory := GetCurrentDir;   DeleteFile(CurrentDirectory + '\input.txt'); RmDir(PChar(CurrentDirectory + '\docs'));   DeleteFile('c:\input.txt'); RmDir(PChar('c:\docs')); end;  
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.
#E
E
<file:input.txt>.delete(null) <file:docs>.delete(null) <file:///input.txt>.delete(null) <file:///docs>.delete(null)
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 ...
#Kotlin
Kotlin
// version 1.1.2   typealias Matrix = Array<DoubleArray>   fun johnsonTrotter(n: Int): Pair<List<IntArray>, List<Int>> { val p = IntArray(n) { it } // permutation val q = IntArray(n) { it } // inverse permutation val d = IntArray(n) { -1 } // direction = 1 or -1 var sign = 1 val perms = mutableLi...
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.
#Factor
Factor
USE: math.floats.env   : try-div ( a b -- ) '[ { +fp-zero-divide+ } [ _ _ /f . ] with-fp-traps ] try ;
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.
#Fancy
Fancy
def divide: x by: y { try { x / y } catch DivisionByZeroError => e { e message println # prints error message } }  
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...
#Delphi
Delphi
  function IsNumericString(const inStr: string): Boolean; var i: extended; begin Result := TryStrToFloat(inStr,i); 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...
#Dyalect
Dyalect
func String.IsNumeric() { try { parse(this) is Integer or Float } catch _ { false } }   var str = "1234567" print(str.IsNumeric())
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 ...
#Groovy
Groovy
class StringUniqueCharacters { static void main(String[] args) { printf("%-40s  %2s  %10s  %8s  %s  %s%n", "String", "Length", "All Unique", "1st Diff", "Hex", "Positions") printf("%-40s  %2s  %10s  %8s  %s  %s%n", "------------------------", "------", "----------", "--------", "---", "---------") ...
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...
#NetLogo
NetLogo
  to-report split [ string ]  ;; utility reporter to split a string into a list report n-values length string [ [ n ] -> item n string ] end   to-report collapse [ string ]  ;; reporter that actually does the collapse function ifelse ( string = "" ) [ report "" ] [ report reduce [ [ a b ] -> (word a ifelse-v...
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...
#Nim
Nim
import unicode, strformat   proc collapse(s: string) = let original = s.toRunes echo fmt"Original: length = {original.len}, string = «««{s}»»»" var previous = Rune(0) var collapsed: seq[Rune] for rune in original: if rune != previous: collapsed.add(rune) previous = rune echo fmt"Collapsed: ...
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...
#Perl
Perl
use strict; use warnings; use utf8; binmode STDOUT, ":utf8";   my @lines = split "\n", <<~'STRINGS';   "If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ..1111111111111111111111111111111111111111111111111111111111111117777888 I never give 'em hell, I just tell the truth, and they think...
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...
#Kotlin
Kotlin
fun analyze(s: String) { println("Examining [$s] which has a length of ${s.length}:") if (s.length > 1) { val b = s[0] for ((i, c) in s.withIndex()) { if (c != b) { println(" Not all characters in the string are the same.") println(" '$c' (0x${In...