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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...
#Lambdatalk
Lambdatalk
  {def firstDifferingChar {def firstDifferingChar.r {lambda {:w :i :n} {if {or {> :i :n} {= {+ :i 1} {W.length :w}}} then all characters are the same else {if {not {W.equal? {W.get :i :w} {W.get {+ :i 1} :w}}} then at position {+ :i 1} {W.get :i :w} becomes {W.get {+ :i 1} :w} else {firstDifferingCh...
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...
#Phix
Phix
without js -- threads integer fork1 = init_cs(), fork2 = init_cs(), fork3 = init_cs(), fork4 = init_cs(), fork5 = init_cs() integer terminate = 0 -- control flag procedure person(sequence name, atom left_fork, atom right_fork) -- (except Russell, who gets left and rig...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#PHP
PHP
  <?php $Anerisia = array(31,28,31,30,31,30,31,31,30,31,30,31); $MONTHS = array("Choas","Discord","Confusion","Bureacracy","The Aftermath"); $DAYS = array("Setting Orange","Sweetmorn","BoomTime","Pungenday","Prickle-Prickle"); $Dsuff = array('th','st','nd','rd','th','th','th','th','th','th'); $Holy5...
http://rosettacode.org/wiki/Dijkstra%27s_algorithm
Dijkstra's algorithm
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task. Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro...
#PHP
PHP
  <?php function dijkstra($graph_array, $source, $target) { $vertices = array(); $neighbours = array(); foreach ($graph_array as $edge) { array_push($vertices, $edge[0], $edge[1]); $neighbours[$edge[0]][] = array("end" => $edge[1], "cost" => $edge[2]); $neighbours[$edge[1]][] = array...
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...
#Lua
Lua
function digital_root(n, base) p = 0 while n > 9.5 do n = sum_digits(n, base) p = p + 1 end return n, p end   print(digital_root(627615, 10)) print(digital_root(39390, 10)) print(digital_root(588225, 10)) print(digital_root(393900588225, 10))
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...
#MAD
MAD
NORMAL MODE IS INTEGER VECTOR VALUES INP = $I12*$ VECTOR VALUES OUTP = $I12,S1,I12*$ BASE = 10   R READ NUMBERS UNTIL 0 INPUT RDNUM READ FORMAT INP,NUMBER WHENEVER NUMBER.NE.0 SUMMAT PERS = 0 DSUM = 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...
#Python
Python
import re from itertools import product   problem_re = re.compile(r"""(?msx)(?:   # Multiple names of form n1, n2, n3, ... , and nK (?P<namelist> [a-zA-Z]+ (?: , \s+ [a-zA-Z]+)* (?: ,? \s+ and) \s+ [a-zA-Z]+ )   # Flexible floor count (2 to 10 floors) | (?: .* house \s+ that \s+ contains \s+ only \s+ (?P<floorcount>...
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 ...
#JavaScript
JavaScript
function dot_product(ary1, ary2) { if (ary1.length != ary2.length) throw "can't find dot product: arrays have different lengths"; var dotprod = 0; for (var i = 0; i < ary1.length; i++) dotprod += ary1[i] * ary2[i]; return dotprod; }   print(dot_product([1,3,-5],[4,-2,-1])); // ==> 3 prin...
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...
#PHP
PHP
<?php   function squeezeString($string, $squeezeChar) { $previousChar = null; $squeeze = ''; $charArray = preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY); for ($i = 0 ; $i < count($charArray) ; $i++) { $currentChar = $charArray[$i]; if ($previousChar !== $currentChar || $currentChar ...
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 ...
#Python
Python
import math   dxs = [-0.533, 0.27, 0.859, -0.043, -0.205, -0.127, -0.071, 0.275, 1.251, -0.231, -0.401, 0.269, 0.491, 0.951, 1.15, 0.001, -0.382, 0.161, 0.915, 2.08, -2.337, 0.034, -0.126, 0.014, 0.709, 0.129, -1.093, -0.483, -1.193, 0.02, -0.051, 0.047, -0.095, 0.695, 0.34, -0.182, 0.287, 0.213,...
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...
#BCPL
BCPL
get "libhdr"   let start() be for p=2 to 6 by 2 for s=1 to 7 for f=1 to 7 if p~=s & s~=f & p~=f & p+s+f=12 then writef("%N %N %N*N", p, s, f)
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...
#BASIC
BASIC
print "--police-- --sanitation-- --fire--"   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 or sanitation = police then continue for if sanitation >= 1 and sanitation <= 7 then print r...
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 ...
#J
J
coclass 'delegator' operation=:3 :'thing__delegate ::thing y' thing=: 'default implementation'"_ setDelegate=:3 :'delegate=:y' NB. result is the reference to our new delegate delegate=:<'delegator'   coclass 'delegatee1'   coclass 'delegatee2' thing=: 'delegate implementation'"_   NB. set context in case thi...
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 ...
#Java
Java
interface Thingable { String thing(); }   class Delegator { public Thingable delegate;   public String operation() { if (delegate == null) return "default implementation"; else return delegate.thing(); } }   class Delegate implements Thingable { public String ...
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)...
#Lambdatalk
Lambdatalk
  Here we present a rasterized version based on a single function "isInside".   1) isInside   Given A, B, C, P is in the triangle ABC if the three cross-products PA^PB, PB^PC and PC^PA are of equal sign.   {def isInside {lambda {:a :b :c :p} {let { {:ax {car :a}} {:ay {cdr :a}} {:bx {car :b}} {:by {cdr :b...
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.
#Elena
Elena
import system'io;   public program() { File.assign("output.txt").delete();   File.assign("\output.txt").delete();   Directory.assign("docs").delete();   Directory.assign("\docs").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.
#Elixir
Elixir
File.rm!("input.txt") File.rmdir!("docs") File.rm!("/input.txt") File.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 ...
#Lambdatalk
Lambdatalk
  {require lib_matrix}   {M.determinant {M.new [[1,2,3], [4,5,6], [7,8,9]]}} -> 0 {M.permanent {M.new [[1,2,3], [4,5,6], [7,8,9]]}} -> 450   {M.determinant {M.new [[1,2,3], [4,5,6], [7,8,-9]]}} -> 54 {M.permanent {M.new [[1,2,3], [4,5,6], [7,8,...
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.
#Forth
Forth
: safe-/ ( x y -- x/y ) ['] / catch -55 = if cr ." divide by zero!" 2drop 0 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.
#Fortran
Fortran
  program rosetta_divbyzero implicit none integer, parameter :: rdp = kind(1.d0) real(rdp) :: normal,zero   normal = 1.d0 zero = 0.d0   call div_by_zero_check(normal,zero)   contains   subroutine div_by_zero_check(x,y) use, intrinsic :: ieee_exceptions use, intrinsic :: ieee_arithm...
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.C3.A9j.C3.A0_Vu
Déjà Vu
is-numeric s: true try: drop to-num s catch value-error: not   for v in [ "1" "0" "3.14" "hello" "12e3" "12ef" "-3" ]: !.( v is-numeric v )
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...
#E
E
def isNumeric(specimen :String) { try { <import:java.lang.makeDouble>.valueOf(specimen) return true } catch _ { return 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 ...
#Haskell
Haskell
import Data.List (groupBy, intersperse, sort, transpose) import Data.Char (ord, toUpper) import Data.Function(on) import Numeric (showHex)     hexFromChar :: Char -> String hexFromChar c = map toUpper $ showHex (ord c) ""   string :: String -> String string xs = ('\"' : xs) <> "\""   char :: Char -> String char c = ['...
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...
#Phix
Phix
with javascript_semantics constant tests = {"", `"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 it's...
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...
#PHP
PHP
<?php   function collapseString($string) { $previousChar = null; $collapse = ''; $charArray = preg_split('//u', $string, -1, PREG_SPLIT_NO_EMPTY); for ($i = 0 ; $i < count($charArray) ; $i++) { $currentChar = $charArray[$i]; if ($previousChar !== $currentChar) { $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...
#Lua
Lua
function analyze(s) print(string.format("Examining [%s] which has a length of %d:", s, string.len(s))) if string.len(s) > 1 then local last = string.byte(string.sub(s,1,1)) for i=1,string.len(s) do local c = string.byte(string.sub(s,i,i)) if last ~= c then ...
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...
#PicoLisp
PicoLisp
(de dining (Name State) (loop (prinl Name ": " State) (state 'State # Dispatch according to state (thinking 'hungry) # If thinking, get hungry (hungry # If hungry, grab random fork (if (rand T) (and ...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#PicoLisp
PicoLisp
(de disdate (Year Month Day) (let? Date (date Year Month Day) (let (Leap (date Year 2 29) D (- Date (date Year 1 1))) (if (and Leap (= 2 Month) (= 29 Day)) (pack "St. Tib's Day, YOLD " (+ Year 1166)) (and Leap (>= D 60) (dec 'D)) (pack (get ...
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...
#PicoLisp
PicoLisp
(de neighbor (X Y Cost) (push (prop X 'neighbors) (cons Y Cost)) (push (prop Y 'neighbors) (cons X Cost)) )   (de dijkstra (Curr Dest) (let Cost 0 (until (== Curr Dest) (let (Min T Next) (for N (; Curr neighbors) (with (car N) (let D (+ Cost (cdr N))...
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...
#Malbolge
Malbolge
seq[n_, b_] := FixedPointList[Total[IntegerDigits[#, b]] &, n]; root[n_Integer, base_: 10] := If[base == 10, #, BaseForm[#, base]] &[Last[seq[n, base]]] persistance[n_Integer, base_: 10] := Length[seq[n, base]] - 2;
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...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
seq[n_, b_] := FixedPointList[Total[IntegerDigits[#, b]] &, n]; root[n_Integer, base_: 10] := If[base == 10, #, BaseForm[#, base]] &[Last[seq[n, base]]] persistance[n_Integer, base_: 10] := Length[seq[n, 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...
#R
R
  names = unlist(strsplit("baker cooper fletcher miller smith", " "))   test <- function(floors) { f <- function(name) which(name == floors) if ((f('baker') != 5) && (f('cooper') != 1) && (any(f('fletcher') == 2:4)) && (f('miller') > f('cooper')) && (abs(f('fletcher') - f('cooper')) > 1) && ...
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 ...
#jq
jq
  def dot(x; y): reduce range(0;x|length) as $i (0; . + x[$i] * y[$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 ...
#Jsish
Jsish
/* Dot product, in Jsish */ function dot_product(ary1, ary2) { if (ary1.length != ary2.length) throw "can't find dot product: arrays have different lengths"; var dotprod = 0; for (var i = 0; i < ary1.length; i++) dotprod += ary1[i] * ary2[i]; return dotprod; }   ;dot_product([1,3,-5],[4,-2,-1]); ;//dot_...
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...
#Prolog
Prolog
squeeze_( [], _, [] ). squeeze_( [A], _, [A] ). squeeze_( [A,A|T], A, R ) :- squeeze_( [A|T], A, R ). squeeze_( [A,A|T], B, [A|R] ) :- dif( A, B ), squeeze_( [A|T], B, R ). squeeze_( [A,B|T], S, [A|R] ) :- dif( A, B ), squeeze_( [B|T], S, R ).   squeeze( Str, SqueezeChar, Collapsed ) :- string_chars( Str, Chars ), ...
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...
#Python
Python
from itertools import groupby   def squeezer(s, txt): return ''.join(item if item == s else ''.join(grp) for item, grp in groupby(txt))   if __name__ == '__main__': strings = [ "", '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ', ...
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 ...
#Racket
Racket
#lang racket (require math/distributions math/statistics plot)   (define 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 0.129 -1.093 -0.483 -1.193 0.020 -0.051 ...
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 ...
#Raku
Raku
sub mean { @_ R/ [+] @_ } sub stddev { # <(x - <x>)²> = <x²> - <x>² sqrt( mean(@_ »**» 2) - mean(@_)**2 ) }   constant @dz = < -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 ...
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...
#C
C
  #include<stdio.h>   int main() { int police,sanitation,fire;   printf("Police Sanitation Fire\n"); printf("----------------------------------");   for(police=2;police<=6;police+=2){ for(sanitation=1;sanitation<=7;sanitation++){ for(fire=1;fire<=7;fire++){ if(police!=sanitation && 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 ...
#JavaScript
JavaScript
function Delegator() { this.delegate = null ; this.operation = function(){ if(this.delegate && typeof(this.delegate.thing) == 'function') return this.delegate.thing() ; return 'default implementation' ; } }   function Delegate() { this.thing = function(){ return 'Delegate 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 ...
#Julia
Julia
module Delegates   export Delegator, Delegate   struct Delegator{T} delegate::T end   struct Delegate end   operation(x::Delegator) = thing(x.delegate) thing(::Any) = "default implementation" thing(::Delegate) = "delegate implementation"   end # module Delegates
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)...
#Lua
Lua
function det2D(p1,p2,p3) return p1.x * (p2.y - p3.y) + p2.x * (p3.y - p1.y) + p3.x * (p1.y - p2.y) end   function checkTriWinding(p1,p2,p3,allowReversed) local detTri = det2D(p1,p2,p3) if detTri < 0.0 then if allowReversed then local t = p3 p3 = p2 ...
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.
#Emacs_Lisp
Emacs Lisp
(delete-file "input.txt") (delete-directory "docs") (delete-file "/input.txt") (delete-directory "/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.
#Erlang
Erlang
  -module(delete). -export([main/0]).   main() -> % current directory ok = file:del_dir( "docs" ), ok = file:delete( "input.txt" ), % root directory ok = file:del_dir( "/docs" ), ok = file:delete( "/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 ...
#Lua
Lua
-- Johnson–Trotter permutations generator _JT={} function JT(dim) local n={ values={}, positions={}, directions={}, sign=1 } setmetatable(n,{__index=_JT}) for i=1,dim do n.values[i]=i n.positions[i]=i n.directions[i]=-1 end return n end   function _JT:largestMobile() for i=#self.values,1,-1 do ...
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.
#FreeBASIC
FreeBASIC
' FB 1.05.0 Win64   Const divByZeroResult As Integer = -9223372036854775808   Sub CheckForDivByZero(result As Integer) If result = divByZeroResult Then Print "Division by Zero" Else Print "Division by Non-Zero" End If End Sub   Dim As Integer x, y   x = 0 : y = 0 CheckForDivByZero(x/y) ' automatic conv...
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.
#FutureBasic
FutureBasic
  include "ConsoleWindow"   on error stop dim as long a print a / 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.
#Gambas
Gambas
Public Sub Main()   Try Print 1 / 0 If Error Then Print Error.Text   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...
#EasyLang
EasyLang
func is_numeric a$ . r . h = number a$ r = 1 - error # because every variable must be used h = h . for s$ in [ "abc" "21a" "1234" "-13" "7.65" ] call is_numeric s$ r if r = 1 print s$ & " is numeric" else print s$ & " is not numeric" . .
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...
#EchoLisp
EchoLisp
  (string->number "albert") → #f (string->number -666) → -666 (if (string->number 666) 'YES 'NO) → YES  
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 ...
#J
J
  rc_unique=: monad define string=. '"' , y , '"' self_classification=. = y NB. deprecated- consumes space proportional to the squared tally of y (*: # y) is_unique=. self_classification =&# y if. is_unique do. (# y) ; string ; 'unique' else. duplicate_masks=. (#~ (1 < +/"1)) self_classification duplicate_...
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 ...
#Java
Java
  import java.util.HashMap; import java.util.Map;   // Title: Determine if a string has all unique characters   public class StringUniqueCharacters {   public static void main(String[] args) { System.out.printf("%-40s  %2s  %10s  %8s  %s  %s%n", "String", "Length", "All Unique", "1st Diff", "Hex", "Positi...
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...
#PL.2FM
PL/M
100H: BDOS: PROCEDURE (FN, ARG); DECLARE FN BYTE, ARG ADDRESS; GO TO 5; END BDOS; EXIT: PROCEDURE; CALL BDOS(0,0); END EXIT; PRINT: PROCEDURE (S); DECLARE S ADDRESS; CALL BDOS(9, S); END PRINT;   /* PRINT NUMBER */ PRINT$NUMBER: PROCEDURE (N); DECLARE S (6) BYTE INITIAL ('.....$'); DECLARE (N, P) ADDRESS, C BAS...
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...
#Prolog
Prolog
collapse_( [], [] ). collapse_( [A], [A] ). collapse_( [A,A|T], R ) :- collapse_( [A|T], R ). collapse_( [A,B|T], [A|R] ) :- dif( A, B ), collapse_( [B|T], R ).   collapse( Str, Collapsed ) :- string_chars( Str, Chars ), collapse_( Chars, Result ), string_chars( Collapsed, Result ).
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...
#Maple
Maple
CheckSame:=proc(s) local i, index; printf("input: \"%s\", length: %a\n", s, StringTools:-Length(s)); for i from 2 to StringTools:-Length(s) do if (s[i - 1] <> s[i]) then printf("The given string has different characters.\n"); printf("The first different character is %a (0x%x) which appears at index %a.\n\n",...
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...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
ClearAll[AllSameCharacters] AllSameCharacters[s_String] := Module[{c = Characters[s], i = 0, tf}, If[Length[c] > 1, tf = AllTrue[Rest[c], (i++; # == First[c]) &]; If[tf, Print["input = \"", s, "\", Length = ", StringLength[s], ", All the same!"] , Print["input = \"", s, "\", 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...
#Pike
Pike
class Philosopher { string name; object left; object right;   void create(string _name, object _left, object _right) { name = _name; left = _left; right = _right; }   void take_forks() { if (left->take(this) && right->take(this)) { wr...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#Pike
Pike
> Calendar.Discordian.now()->format_ext_ymd(); Result: "Pungenday, 59 Bureaucracy 3177" > Calendar.Discordian.Day(Calendar.Day(2011,11,11))->format_ext_ymd(); Result: "Setting Orange, 23 The Aftermath 3177" > Calendar.Discordian.Day(Calendar.Badi.Day(168,13,9))->format_ext_ymd(); Result: "Setting Orange, 23 The Af...
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...
#Prolog
Prolog
rpath([target|reversed_path], distance)
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...
#Modula-2
Modula-2
MODULE DigitalRoot; FROM FormatString IMPORT FormatString; FROM Terminal IMPORT WriteString,WriteLn,ReadChar;   TYPE Root = RECORD persistence,root : LONGINT; END;   PROCEDURE digitalRoot(inRoot,base : LONGINT) : Root; VAR root,persistence,num : LONGINT; BEGIN root := ABS(inRoot); persistence :=...
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...
#Racket
Racket
  #lang racket   ;; A quick `amb' implementation (define fails '()) (define (fail) (if (pair? fails) ((car fails)) (error "no more choices!"))) (define (amb xs) (let/cc k (set! fails (cons k fails))) (if (pair? xs) (begin0 (car xs) (set! xs (cdr xs))) (begin (set! fails (cdr fails)) (fail)))) (define (assert ...
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 ...
#Julia
Julia
x = [1, 3, -5] y = [4, -2, -1] z = dot(x, y) z = x'*y z = x ⋅ y
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 ...
#K
K
+/1 3 -5 * 4 -2 -1 3   1 3 -5 _dot 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...
#R
R
squeeze_string <- function(string, character){   str_iterable <- strsplit(string, "")[[1]]   message(paste0("Original String: ", "<<<", string, ">>>\n", "Length: ", length(str_iterable), "\n", "Character: ", character))   detect <- rep(TRUE, length(str_iterable))     ...
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...
#Racket
Racket
#lang racket/base   (define (squeeze-string s c) (let loop ((cs (string->list s)) (squeezing? #f) (l 0) (acc null)) (cond [(null? cs) (values l (list->string (reverse acc)))] [(and squeezing? (char=? (car cs) c)) (loop (cdr cs) #t l acc)] [else (loop (cdr cs) (char=? (car cs) c) (add1 l) (cons...
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 ...
#Ruby
Ruby
def funnel(dxs, &rule) x, rxs = 0, [] for dx in dxs rxs << (x + dx) x = rule[x, dx] end rxs end   def mean(xs) xs.inject(:+) / xs.size end   def stddev(xs) m = mean(xs) Math.sqrt(xs.inject(0.0){|sum,x| sum + (x-m)**2} / xs.size) end   def experiment(label, dxs, dys, &rule) rxs, rys = funnel(dxs, &...
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...
#C.23
C#
using System; public class Program { public static void Main() { for (int p = 2; p <= 7; p+=2) { for (int s = 1; s <= 7; s++) { int f = 12 - p - s; if (s >= f) break; if (f > 7) continue; if (s == p || f == p) continue; //not even n...
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 ...
#Kotlin
Kotlin
// version 1.1.51   interface Thingable { fun thing(): String? }   class Delegate(val responds: Boolean) : Thingable { override fun thing() = if (responds) "delegate implementation" else null }   class Delegator(d: Delegate) : Thingable by d { fun operation() = thing() ?: "default implementation" }   fun ma...
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 ...
#Latitude
Latitude
Delegator ::= Object clone tap { self delegate := Nil. self clone := { Parents above (parent self, 'clone) call tap { self delegate := #'(self delegate). }. }. self operation := { localize. if { this delegate slot? 'thing. } then { this delegate thing. } else { "default imp...
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)...
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
p1 = Polygon@{{0, 0}, {5, 0}, {0, 5}}; p2 = Polygon@{{0, 0}, {5, 0}, {0, 6}}; ! RegionDisjoint[p1, p2]   p1 = Polygon@{{0, 0}, {0, 5}, {5, 0}}; p2 = Polygon@{{0, 0}, {0, 5}, {5, 0}}; ! RegionDisjoint[p1, p2]   p1 = Polygon@{{0, 0}, {5, 0}, {0, 5}}; p2 = Polygon@{{-10, 0}, {-5, 0}, {-1, 6}}; ! RegionDisjoint[p1, p2]   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.
#F.23
F#
open System.IO   [<EntryPoint>] let main argv = let fileName = "input.txt" let dirName = "docs" for path in ["."; "/"] do ignore (File.Delete(Path.Combine(path, fileName))) ignore (Directory.Delete(Path.Combine(path, dirName))) 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.
#Factor
Factor
"docs" "/docs" [ delete-tree ] bi@ "input.txt" "/input.txt" [ delete-file ] bi@
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 ...
#Maple
Maple
M:=<<2|9|4>,<7|5|3>,<6|1|8>>:   with(LinearAlgebra):   Determinant(M); Permanent(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 ...
#Mathematica.2FWolfram_Language
Mathematica/Wolfram Language
Permanent[m_List] := With[{v = Array[x, Length[m]]}, Coefficient[Times @@ (m.v), Times @@ v] ]
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.
#Go
Go
package main   import "fmt"   func divCheck(x, y int) (q int, ok bool) { defer func() { recover() }() q = x / y return q, true }   func main() { fmt.Println(divCheck(3, 2)) fmt.Println(divCheck(3, 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.
#Groovy
Groovy
def dividesByZero = { double n, double d -> assert ! n.infinite : 'Algorithm fails if the numerator is already infinite.' (n/d).infinite || (n/d).naN }
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...
#Elixir
Elixir
defmodule RC do def is_numeric(str) do case Float.parse(str) do {_num, ""} -> true _ -> false end end end   ["123", "-12.3", "123.", ".05", "-12e5", "+123", " 123", "abc", "123a", "12.3e", "1 2"] |> Enum.filter(&RC.is_numeric/1)
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...
#Erlang
Erlang
is_numeric(L) -> Float = (catch erlang:list_to_float(L)), Int = (catch erlang:list_to_integer(L)), is_number(Float) orelse is_number(Int).
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 ...
#JavaScript
JavaScript
(() => { 'use strict';   // duplicatedCharIndices :: String -> Maybe (Char, [Int]) const duplicatedCharIndices = s => { const duplicates = filter(g => 1 < g.length)( groupBy(on(eq)(snd))( sortOn(snd)( zip(enumFrom(0))(chars(s)) ...
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...
#PureBasic
PureBasic
EnableExplicit DataSection STR1: Data.s "" STR2: Data.s "'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln " STR3: Data.s "..1111111111111111111111111111111111111111111111111111111111111117777888" STR4: Data.s "I never give 'em hell, I just tell the truth, and they think it's hell....
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...
#Python
Python
from itertools import groupby   def collapser(txt): return ''.join(item for item, grp in groupby(txt))   if __name__ == '__main__': strings = [ "", '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ', "..1111111111111111111111111111111111111111111111111...
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...
#Nanoquery
Nanoquery
def analyze(s) s = str(s) println "Examining [" + s + "] which has a length of " + str(len(s)) + ":"   if len(s) < 2 println "\tAll characters in the string are the same." return end   for i in range(0, len(s) - 2) if s[i] != s[i + 1] println "\tNot all characters...
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...
#Nim
Nim
import strformat   proc analyze(str: string) = if str.len() > 1: var first = str[0] for i, c in str: if c != first: echo "'", str, "': [len: ", str.len(), "] not all characters are the same. starts to differ at index ", i, ": '", first, "' != '", c, "'...
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...
#Prolog
Prolog
dining_philosophers :- new(D, window('Dining philosophers')), new(S, window('Dining philosophers : statistics')), send(D, size, new(_, size(800,800))),   new(E, ellipse(400,400)), send(E, center, point(400,400)), send(D, display, E),   new(F1, fork(0)), new(F2, fork(1)), new(F3, fork(2)), new(F4, fork(3)), n...
http://rosettacode.org/wiki/Discordian_date
Discordian date
Task Convert a given date from the   Gregorian calendar   to the   Discordian calendar.
#PowerBASIC
PowerBASIC
#COMPILE EXE #DIM ALL   'change this for systems that use a different character $DATESEP = "-"   FUNCTION day(date AS STRING) AS LONG 'date is same format as date$ DIM tmpdash1 AS LONG, tmpdash2 AS LONG tmpdash1 = INSTR(date, $DATESEP) tmpdash2 = INSTR(-1, date, $DATESEP) FUNCTION = VAL(MID$(date, t...
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...
#Python
Python
from collections import namedtuple, deque from pprint import pprint as pp     inf = float('inf') Edge = namedtuple('Edge', ['start', 'end', 'cost'])   class Graph(): def __init__(self, edges): self.edges = [Edge(*edge) for edge in edges] # print(dir(self.edges[0])) self.vertices = {e.start f...
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...
#Nanoquery
Nanoquery
def digital_root(n) ap = 0 n = +(int(n)) while n >= 10 sum = 0 for digit in str(n) sum += int(digit) end n = sum ap += 1 end return {ap, n} end   println "here"   if main values = {627615, 39390, 588825, 393900588225, 55} for n in values aproot = digital_root(n) println format("%12d has additive...
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...
#NetRexx
NetRexx
/* NetRexx ************************************************************ * Test digroot **********************************************************************/ Say 'number -> digital_root persistence' test_digroot(7 ,7, 0) test_digroot(627615 ,9, 2) test_digroot(39390 ,6, 2) test_digroot(588225 ...
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...
#Raku
Raku
use MONKEY-SEE-NO-EVAL;   sub parse_and_solve ($text) { my %ids; my $expr = (grammar { state $c = 0; rule TOP { <fact>+ { make join ' && ', $<fact>>>.made } }   rule fact { <name> (not)? <position> { make sprintf $<position>.made.fmt($0 ?? "!(%s)" !! "%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 ...
#Klingphix
Klingphix
:sq_mul  %c %i ( ) !c len [  !i $i get rot $i get rot * $c swap 0 put !c ] for $c ;   :sq_sum 0 swap len [ get rot + swap ] for swap ;   ( 1 3 -5 ) ( 4 -2 -1 ) sq_mul sq_sum pstack   " " input
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 ...
#Kotlin
Kotlin
fun dot(v1: Array<Double>, v2: Array<Double>) = v1.zip(v2).map { it.first * it.second }.reduce { a, b -> a + b }   fun main(args: Array<String>) { dot(arrayOf(1.0, 3.0, -5.0), arrayOf(4.0, -2.0, -1.0)).let { println(it) } }
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...
#Raku
Raku
map { my $squeeze = $^phrase; sink $^reg; $squeeze ~~ s:g/($reg)$0+/$0/; printf "\nOriginal length: %d <<<%s>>>\nSqueezable on \"%s\": %s\nSqueezed length: %d <<<%s>>>\n", $phrase.chars, $phrase, $reg.uniname, $phrase ne $squeeze, $squeeze.chars, $squeeze }, '', ' ', '"If I were two-faced, ...
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...
#REXX
REXX
/*REXX program "squeezes" all immediately repeated characters in a string (or strings). */ @.= /*define a default for the @. array. */ #.1= ' '; @.1= #.2= '-'; @.2= '"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ' #.3= '7'; @.3= ..111111111111111...
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 ...
#Sidef
Sidef
func x̄(a) { a.sum / a.len }   func σ(a) { sqrt(x̄(a.map{.**2}) - x̄(a)**2) }   const Δ = (%n< -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 -1.19...
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...
#C.2B.2B
C++
  #include <iostream> #include <iomanip>   int main( int argc, char* argv[] ) { int sol = 1; std::cout << "\t\tFIRE\t\tPOLICE\t\tSANITATION\n"; for( int f = 1; f < 8; f++ ) { for( int p = 1; p < 8; p++ ) { for( int s = 1; s < 8; s++ ) { if( f != p && f != s && p != s && !...
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 ...
#Logtalk
Logtalk
% define a category for holding the interface % and implementation for delegator objects   :- category(delegator).   :- public(delegate/1). :- public(set_delegate/1).   :- private(delegate_/1). :- dynamic(delegate_/1).   delegate(Delegate) :- ::delegate_(Delegate).   set_delegate(Delegat...
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 ...
#Lua
Lua
local function Delegator() return { operation = function(self) if (type(self.delegate)=="table") and (type(self.delegate.thing)=="function") then return self.delegate:thing() else return "default implementation" end end } end   local function Delegate() return { thing...
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)...
#Modula-2
Modula-2
MODULE Overlap; FROM EXCEPTIONS IMPORT AllocateSource,ExceptionSource,GetMessage,RAISE; FROM LongStr IMPORT RealToFixed; FROM Terminal IMPORT WriteString,WriteLn,ReadChar;   TYPE Point = RECORD x,y : LONGREAL; END; Triangle = RECORD p1,p2,p3 : Point; END;   VAR TextWinExSrc : Excepti...
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.
#Forth
Forth
s" input.txt" delete-file throw s" /input.txt" delete-file throw
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.
#Fortran
Fortran
OPEN (UNIT=5, FILE="input.txt", STATUS="OLD") ! Current directory CLOSE (UNIT=5, STATUS="DELETE") OPEN (UNIT=5, FILE="/input.txt", STATUS="OLD") ! Root directory CLOSE (UNIT=5, STATUS="DELETE")