task_url
stringlengths
30
116
task_name
stringlengths
2
86
task_description
stringlengths
0
14.4k
language_url
stringlengths
2
53
language_name
stringlengths
1
52
code
stringlengths
0
61.9k
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#PARI.2FGP
PARI/GP
issquare(n, &m)
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Pascal
Pascal
use Scalar::Util qw(refaddr); print refaddr(\my $v), "\n"; # 140502490125712
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Perl
Perl
use Scalar::Util qw(refaddr); print refaddr(\my $v), "\n"; # 140502490125712
http://rosettacode.org/wiki/AKS_test_for_primes
AKS test for primes
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles. The theorem on which the test is based can be stated as follows:   a number   p {\displaystyle p}   is prime   if and only if   all the coefficients of the polynomial ...
#Delphi
Delphi
  (lib 'math.lib) ;; 1 - x^p  : P = (1 0 0 0 ... 0 -1) (define (mono p) (append (list 1) (make-list (1- p) 0) (list -1)))   ;; compute (x-1)^p , p >= 1 (define (aks-poly p) (poly-pow (list -1 1) p))   ;; (define (show-them n) (for ((p (in-range 1 n))) (writeln 'p p (poly->string 'x (aks-poly p)))))   ;; aks-tes...
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#FreeBASIC
FreeBASIC
#include "isprime.bas"   function digsum( n as uinteger ) as uinteger dim as uinteger s while n s+=n mod 10 n\=10 wend return s end function   dim as uinteger s   print "Prime","Digit Sum" for i as uinteger = 2 to 499 if isprime(i) then s = digsum(i) if isprime(s) the...
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#Free_Pascal
Free Pascal
  Program AdditivePrimes; Const max_number = 500;   Var is_prime : array Of Boolean;   Procedure sieve(Var arr: Array Of boolean ); {use Sieve of Eratosthenes to find all primes to max number} Var i,j : NativeUInt;   Begin For i := 2 To high(arr) Do arr[i] := True; // set all bits to be True For i := 2 To high...
http://rosettacode.org/wiki/Algebraic_data_types
Algebraic data types
Some languages offer direct support for algebraic data types and pattern matching on them. While this of course can always be simulated with manual tagging and conditionals, it allows for terse code which is easy to read, and can represent the algorithm directly. Task As an example, implement insertion in a red-bla...
#Tailspin
Tailspin
  processor RedBlackTree data node <{VOID}|{colour: <='black'|='red'>, left: <node>, right: <node>, value: <> VOID}> local @: {}; sink insert templates balance when <{colour: <='black'>, left: <{ colour: <='red'> left: <{colour: <='red'>}>}>}> do { colour: 'red', left: { $.left.left......
http://rosettacode.org/wiki/Algebraic_data_types
Algebraic data types
Some languages offer direct support for algebraic data types and pattern matching on them. While this of course can always be simulated with manual tagging and conditionals, it allows for terse code which is easy to read, and can represent the algorithm directly. Task As an example, implement insertion in a red-bla...
#Tcl
Tcl
# From http://wiki.tcl.tk/9547 package require Tcl 8.5 package provide datatype 0.1   namespace eval ::datatype { namespace export define match matches namespace ensemble create   # Datatype definitions proc define {type = args} { set ns [uplevel 1 { namespace current }] fore...
http://rosettacode.org/wiki/Almost_prime
Almost prime
A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   where   k = 2 {\displaystyl...
#Icon_and_Unicon
Icon and Unicon
link "factors"   procedure main() every writes(k := 1 to 5,": ") do every writes(right(genKap(k),5)\10|"\n") end   procedure genKap(k) suspend (k = *factors(n := seq(q)), n) end
http://rosettacode.org/wiki/Anagrams
Anagrams
When two or more words are composed of the same characters, but in a different order, they are called anagrams. Task[edit] Using the word list at   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, find the sets of words that share the same characters that contain the most words in them. Related tasks Word plays ...
#Crystal
Crystal
require "http/client"   response = HTTP::Client.get("http://wiki.puzzlers.org/pub/wordlists/unixdict.txt")   if response.body? words : Array(String) = response.body.split   anagram = {} of String => Array(String)   words.each do |word| key = word.split("").sort.join   if !anagram[key]? anagram[key] ...
http://rosettacode.org/wiki/Angle_difference_between_two_bearings
Angle difference between two bearings
Finding the angle between two bearings is often confusing.[1] Task Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings. Input bearings are expressed in the range   -180   to   +180   degrees. The  result  is also expressed in the range   -180   to   +180   degrees. ...
#PowerShell
PowerShell
  <# .Synopsis Gets the difference between two angles between the values of -180 and 180. To see examples use "Get-Examples" .DESCRIPTION This code uses the modulo operator, this is represented with the "%". The modulo operator returns the remainder after division, as displayed below 3 % 2 = 1 20 % 1...
http://rosettacode.org/wiki/Anagrams/Deranged_anagrams
Anagrams/Deranged anagrams
Two or more words are said to be anagrams if they have the same characters, but in a different order. By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words. Task[edit] Use the word list at uni...
#Racket
Racket
#lang racket (define word-list-file "data/unixdict.txt")   (define (read-words-into-anagram-keyed-hash) (define (anagram-key word) (sort (string->list word) char<?)) (for/fold ((hsh (hash))) ((word (in-lines))) (hash-update hsh (anagram-key word) (curry cons word) null)))   (define anagrams-list (sort ...
http://rosettacode.org/wiki/Anonymous_recursion
Anonymous recursion
While implementing a recursive function, it often happens that we must resort to a separate   helper function   to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects,   and/or the f...
#Ol
Ol
  (define (fibonacci n) (if (> 0 n) "error: negative argument." (let loop ((a 1) (b 0) (count n)) (if (= count 0) b (loop (+ a b) a (- count 1))))))   (print (map fibonacci '(1 2 3 4 5 6 7 8 9 10)))  
http://rosettacode.org/wiki/Amicable_pairs
Amicable pairs
Two integers N {\displaystyle N} and M {\displaystyle M} are said to be amicable pairs if N ≠ M {\displaystyle N\neq M} and the sum of the proper divisors of N {\displaystyle N} ( s u m ( p r o p D i v s ( N ) ) {\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))} ) = M ...
#Nim
Nim
  from math import sqrt   const N = 524_000_000.int32   proc sumProperDivisors(someNum: int32, chk4less: bool): int32 = result = 1 let maxPD = sqrt(someNum.float).int32 let offset = someNum mod 2 for divNum in countup(2 + offset, maxPD, 1 + offset): if someNum mod divNum == 0: result...
http://rosettacode.org/wiki/Animation
Animation
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games.   The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user.   This task demonstrates this. Task Creat...
#ZX_Spectrum_Basic
ZX Spectrum Basic
10 LET t$="Hello world! ": LET lt=LEN t$ 20 LET direction=1 30 PRINT AT 0,0;t$ 40 IF direction THEN LET t$=t$(2 TO )+t$(1): GO TO 60 50 LET t$=t$(lt)+t$( TO lt-1) 60 IF INKEY$<>"" THEN LET direction=NOT direction 70 PAUSE 5: GO TO 30
http://rosettacode.org/wiki/Animate_a_pendulum
Animate a pendulum
One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display. The classic such physical system is a simple gravity pendulum. Task Create a simple physical model of a pendulum and animate it.
#PureBasic
PureBasic
Procedure handleError(x, msg.s) If Not x MessageRequester("Error", msg) End EndIf EndProcedure   #ScreenW = 320 #ScreenH = 210 handleError(OpenWindow(0, 0, 0, #ScreenW, #ScreenH, "Animated Pendulum", #PB_Window_SystemMenu), "Can't open window.") handleError(InitSprite(), "Can't setup sprite display.") handl...
http://rosettacode.org/wiki/Amb
Amb
Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"). The Amb operator takes a v...
#Haxe
Haxe
class RosettaDemo { static var setA = ['the', 'that', 'a']; static var setB = ['frog', 'elephant', 'thing']; static var setC = ['walked', 'treaded', 'grows']; static var setD = ['slowly', 'quickly'];   static public function main() { Sys.print(ambParse([ setA, setB, setC, setD ]).toString()); }   static funct...
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#Astro
Astro
fun accumulator(var sum): :: Real -> _ n => sum += n   let f = accumulator!(5) print f(5) # 10 print f(10) # 20 print f(2.4) # 22.4
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#BBC_BASIC
BBC BASIC
x = FNaccumulator(1) dummy = FN(x)(5) dummy = FNaccumulator(3) PRINT FN(x)(2.3) END   DEF FNaccumulator(sum) LOCAL I%, P%, Q% DIM P% 53 : Q% = !^FNdummy() FOR I% = 0 TO 49 : P%?I% = Q%?I% : NEXT P%!I% = P% : sum = FN(P%+I%)(sum) = P%+I%   DEF FNdum...
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications
Abundant, deficient and perfect number classifications
These define three classifications of positive integers based on their   proper divisors. Let   P(n)   be the sum of the proper divisors of   n   where the proper divisors are all positive divisors of   n   other than   n   itself. if P(n) < n then n is classed as deficient (OEIS A005100). if P(n)...
#8086_Assembly
8086 Assembly
LIMIT: equ 20000 cpu 8086 org 100h mov ax,data ; Set DS and ES to point right after the mov cl,4 ; program, so we can store the array there shr ax,cl mov dx,cs add ax,dx inc ax mov ds,ax mov es,ax mov ax,1 ; Set each element to 1 at the beginning xor di,di mov cx,LIMIT+1 rep stosw mov [2],cx ; Except...
http://rosettacode.org/wiki/Align_columns
Align columns
Given a text file of many lines, where fields within a line are delineated by a single 'dollar' character, write a program that aligns each column of fields by ensuring that words in each column are separated by at least one space. Further, allow for each word in a column to be either left justified, right justified, o...
#ALGOL_68
ALGOL 68
STRING nl = REPR 10; STRING text in list := "Given$a$text$file$of$many$lines,$where$fields$within$a$line$"+nl+ "are$delineated$by$a$single$'dollar'$character,$write$a$program"+nl+ "that$aligns$each$column$of$fields$by$ensuring$that$words$in$each$"+nl+ "column$are$separated$by$at$least$one$space."+nl+ "Further,$...
http://rosettacode.org/wiki/Active_object
Active object
In object-oriented programming an object is active when its state depends on clock. Usually an active object encapsulates a task that updates the object's state. To the outer world the object looks like a normal object with methods that can be called from outside. Implementation of such methods must have a certain sync...
#Delphi
Delphi
  program Active_object;   {$APPTYPE CONSOLE}   uses System.SysUtils, System.Classes;   type TIntegrator = class(TThread) private { Private declarations } interval, s: double; IsRunning: Boolean; protected procedure Execute; override; public k: Tfunc<Double, Double>; constructor Crea...
http://rosettacode.org/wiki/Achilles_numbers
Achilles numbers
This page uses content from Wikipedia. The original article was at Achilles number. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) An Achilles number is a number that is powerful but imperfect. Na...
#Phix
Phix
with javascript_semantics requires("1.0.2") -- [join_by(fmt)] atom t0 = time() constant maxDigits = iff(platform()=JS?10:12) integer pps = new_dict() procedure getPerfectPowers(integer maxExp) atom hi = power(10, maxExp) integer imax = floor(sqrt(hi)) for i=2 to imax do atom p = i while tr...
http://rosettacode.org/wiki/Aliquot_sequence_classifications
Aliquot sequence classifications
An aliquot sequence of a positive integer K is defined recursively as the first member being K and subsequent members being the sum of the Proper divisors of the previous term. If the terms eventually reach 0 then the series for K is said to terminate. There are several classifications for non termination: If the s...
#Haskell
Haskell
divisors :: (Integral a) => a -> [a] divisors n = filter ((0 ==) . (n `mod`)) [1 .. (n `div` 2)]   data Class = Terminating | Perfect | Amicable | Sociable | Aspiring | Cyclic | Nonterminating deriving (Show)   aliquot :: (Integral a) => a -> [a] aliquot 0 = [0] aliquot n = n : (aliquot $ sum $ divisors...
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Oz
Oz
declare %% Creates a new class derived from BaseClass %% with an added feature (==public immutable attribute) fun {AddFeature BaseClass FeatureName FeatureValue} class DerivedClass from BaseClass feat %% "FeatureName" is escaped, otherwise a new variable %% refering to a private feature would...
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Perl
Perl
package Empty;   # Constructor. Object is hash. sub new { return bless {}, shift; }   package main;   # Object. my $o = Empty->new;   # Set runtime variable (key => value). $o->{'foo'} = 1;
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Phix
Phix
class wobbly dynamic -- (pre-define a few fields/methods if you like) end class wobbly wobble = new() ?wobble.jelly -- 0 --?wobble["jelly"] -- for dynamic names use [] wobble.jelly = "green" ?wobble.jelly -- "green"
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Phix
Phix
procedure address() object V integer addr4 -- stored /4 (assuming dword aligned, which it will be) #ilASM{ [32] lea eax,[V] shr eax,2 mov [addr4],eax [64] lea rax,[V] shr rax,2 mov [addr4],rax [] } if machine_bits()=32 then poke4(addr4*4,12...
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#PicoLisp
PicoLisp
: (setq X 7) -> 7   : (adr 'X) -> -2985527269106   : (val (adr -2985527269106)) -> 7   : (set (adr -2985527269106) '(a b c)) -> (a b c)   : X -> (a b c)
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#PL.2FI
PL/I
  declare addr builtin; /* retrieve address of a variable */ declare ptradd builtin; /* pointer addition */ declare cstg builtin; /* retrieve length of the storage of a variable */ declare hbound builtin; /* retrieve the number of elements in an array */   declare p pointe...
http://rosettacode.org/wiki/AKS_test_for_primes
AKS test for primes
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles. The theorem on which the test is based can be stated as follows:   a number   p {\displaystyle p}   is prime   if and only if   all the coefficients of the polynomial ...
#EchoLisp
EchoLisp
  (lib 'math.lib) ;; 1 - x^p  : P = (1 0 0 0 ... 0 -1) (define (mono p) (append (list 1) (make-list (1- p) 0) (list -1)))   ;; compute (x-1)^p , p >= 1 (define (aks-poly p) (poly-pow (list -1 1) p))   ;; (define (show-them n) (for ((p (in-range 1 n))) (writeln 'p p (poly->string 'x (aks-poly p)))))   ;; aks-tes...
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#Frink
Frink
vals = toArray[select[primes[2, 500], {|x| isPrime[sum[integerDigits[x]]]}]] println[formatTable[columnize[vals, 10]]] println["\n" + length[vals] + " values found."]
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#Go
Go
package main   import "fmt"   func isPrime(n int) bool { switch { case n < 2: return false case n%2 == 0: return n == 2 case n%3 == 0: return n == 3 default: d := 5 for d*d <= n { if n%d == 0 { return false } ...
http://rosettacode.org/wiki/Algebraic_data_types
Algebraic data types
Some languages offer direct support for algebraic data types and pattern matching on them. While this of course can always be simulated with manual tagging and conditionals, it allows for terse code which is easy to read, and can represent the algorithm directly. Task As an example, implement insertion in a red-bla...
#Wren
Wren
var R = "R" var B = "B"   class Tree { ins(x) {} // overridden by child classes   insert(x) { // inherited by child classes var t = ins(x) if (t.type == T) return T.new(B, t.le, t.aa, t.ri) if (t.type == E) return E.new() return null } }   class T is Tree { construct...
http://rosettacode.org/wiki/Almost_prime
Almost prime
A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   where   k = 2 {\displaystyl...
#J
J
(10 {. [:~.[:/:~[:,*/~)^:(i.5)~p:i.10 2 3 5 7 11 13 17 19 23 29 4 6 9 10 14 15 21 22 25 26 8 12 18 20 27 28 30 42 44 45 16 24 36 40 54 56 60 81 84 88 32 48 72 80 108 112 120 162 168 176
http://rosettacode.org/wiki/Anagrams
Anagrams
When two or more words are composed of the same characters, but in a different order, they are called anagrams. Task[edit] Using the word list at   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, find the sets of words that share the same characters that contain the most words in them. Related tasks Word plays ...
#D
D
import std.stdio, std.algorithm, std.string, std.exception, std.file;   void main() { string[][ubyte[]] an; foreach (w; "unixdict.txt".readText.splitLines) an[w.dup.representation.sort().release.assumeUnique] ~= w; immutable m = an.byValue.map!q{ a.length }.reduce!max; writefln("%(%s\n%)", an.by...
http://rosettacode.org/wiki/Angle_difference_between_two_bearings
Angle difference between two bearings
Finding the angle between two bearings is often confusing.[1] Task Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings. Input bearings are expressed in the range   -180   to   +180   degrees. The  result  is also expressed in the range   -180   to   +180   degrees. ...
#PureBasic
PureBasic
Procedure.f getDifference (b1.f, b2.f) r.f = Mod((b2 - b1), 360) If r >= 180: r - 360 EndIf PrintN(StrF(b1) + #TAB$ + StrF(b2) + #TAB$ + StrF(r)); EndProcedure   If OpenConsole() PrintN("Input in -180 to +180 range:") getDifference(20.0, 45.0) getDifference(-45.0, 45.0) getDifference(-85.0, 90.0) getD...
http://rosettacode.org/wiki/Anagrams/Deranged_anagrams
Anagrams/Deranged anagrams
Two or more words are said to be anagrams if they have the same characters, but in a different order. By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words. Task[edit] Use the word list at uni...
#Raku
Raku
my @anagrams = 'unixdict.txt'.IO.words .map(*.comb.cache) # explode words into lists of characters .classify(*.sort.join).values # group words with the same characters .grep(* > 1) # only take groups with more than one word .sort(-*[0]) # sort by length o...
http://rosettacode.org/wiki/Anonymous_recursion
Anonymous recursion
While implementing a recursive function, it often happens that we must resort to a separate   helper function   to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects,   and/or the f...
#OxygenBasic
OxygenBasic
  function fiboRatio() as double function fibo( double i, j ) as double if j > 2e12 then return j / i return fibo j, i + j end function return fibo 1, 1 end function   print fiboRatio    
http://rosettacode.org/wiki/Amicable_pairs
Amicable pairs
Two integers N {\displaystyle N} and M {\displaystyle M} are said to be amicable pairs if N ≠ M {\displaystyle N\neq M} and the sum of the proper divisors of N {\displaystyle N} ( s u m ( p r o p D i v s ( N ) ) {\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))} ) = M ...
#Oberon-2
Oberon-2
  MODULE AmicablePairs; IMPORT Out; CONST max = 20000;   VAR i,j: INTEGER; pd: ARRAY max + 1 OF LONGINT;   PROCEDURE ProperDivisorsSum(n: LONGINT): LONGINT; VAR i,sum: LONGINT; BEGIN sum := 0; IF n > 1 THEN INC(sum,1);i := 2; WHILE (i < n) DO IF (n MOD i) = 0 THEN INC(sum,i) END; IN...
http://rosettacode.org/wiki/Animate_a_pendulum
Animate a pendulum
One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display. The classic such physical system is a simple gravity pendulum. Task Create a simple physical model of a pendulum and animate it.
#Python
Python
import pygame, sys from pygame.locals import * from math import sin, cos, radians   pygame.init()   WINDOWSIZE = 250 TIMETICK = 100 BOBSIZE = 15   window = pygame.display.set_mode((WINDOWSIZE, WINDOWSIZE)) pygame.display.set_caption("Pendulum")   screen = pygame.display.get_surface() screen.fill((255,255,255))   PIVOT ...
http://rosettacode.org/wiki/Amb
Amb
Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"). The Amb operator takes a v...
#Icon_and_Unicon
Icon and Unicon
procedure main() s1 := ["the","that","a"] s2 := ["frog","elephant","thing"] s3 := ["walked","treaded","grows"] s4 := ["slowly","quickly"]   write(amb(!s1,!s2,!s3,!s4)) end   procedure amb(exprs[]) s := "" every e := !exprs do { if \c ~== e[1] then fail c := e[-1] s ||...
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#Bracmat
Bracmat
( ( accumulator = . ' ( add sum object . (object=add=$arg+!arg) & !(object.add):?sum & '($($sum)+!arg):(=?(object.add)) & !sum ) ) & accumulator$1:(=?x) & x$5 & accumulator$3 & out$(x$23/10) )
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#Brat
Brat
accumulator = { sum | { n | sum = sum + n } }   x = accumulator 1 x 5 accumulator 3 #Does not affect x p x 2.3 #Prints 8.3 (1 + 5 + 2.3)
http://rosettacode.org/wiki/Ackermann_function
Ackermann function
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree. The Ackermann function is usually defined as follows: A ( m , n ) = { n + 1 if  m = 0 A ( m ...
#11l
11l
F ack2(m, n) -> Int R I m == 0 {(n + 1) } E I m == 1 {(n + 2) } E I m == 2 {(2 * n + 3) } E I m == 3 {(8 * (2 ^ n - 1) + 5) } E I n == 0 {ack2(m - 1, 1) } E ack2(m - 1, ack2(m, n - 1))   print(ack2(0, 0)) print(ack2(3, 4)) print(ack2(4, 1))
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications
Abundant, deficient and perfect number classifications
These define three classifications of positive integers based on their   proper divisors. Let   P(n)   be the sum of the proper divisors of   n   where the proper divisors are all positive divisors of   n   other than   n   itself. if P(n) < n then n is classed as deficient (OEIS A005100). if P(n)...
#AArch64_Assembly
AArch64 Assembly
  /* ARM assembly AARCH64 Raspberry PI 3B or android 64 bits */ /* program numberClassif64.s */   /*******************************************/ /* Constantes file */ /*******************************************/ /* for this file see task include a file in language AArch64 assembly*/ .include "...
http://rosettacode.org/wiki/Align_columns
Align columns
Given a text file of many lines, where fields within a line are delineated by a single 'dollar' character, write a program that aligns each column of fields by ensuring that words in each column are separated by at least one space. Further, allow for each word in a column to be either left justified, right justified, o...
#Amazing_Hopper
Amazing Hopper
  #define IGet(__N__,__X__) [__N__]SGet(__X__)   #include <hbasic.h> #define MAX_LINE 1000   Begin Option Stack 15   Declare as Numeric ( fd, i, index, max token ) as Numeric ( num tokens, size Column, tCells ) as Alpha ( line ) as Numeric ( display Left, display Right, display ...
http://rosettacode.org/wiki/Active_object
Active object
In object-oriented programming an object is active when its state depends on clock. Usually an active object encapsulates a task that updates the object's state. To the outer world the object looks like a normal object with methods that can be called from outside. Implementation of such methods must have a certain sync...
#E
E
def makeIntegrator() { var value := 0.0 var input := fn { 0.0 }   var input1 := input() var t1 := timer.now()   def update() { def t2 := timer.now() def input2 :float64 := input() def dt := (t2 - t1) / 1000   value += (input1 + input2) * dt / 2   t1 := t2 ...
http://rosettacode.org/wiki/Achilles_numbers
Achilles numbers
This page uses content from Wikipedia. The original article was at Achilles number. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) An Achilles number is a number that is powerful but imperfect. Na...
#Raku
Raku
use Prime::Factor; use Math::Root;   sub is-square-free (Int \n) { constant @p = ^100 .map: { next unless .is-prime; .² }; for @p -> \p { return False if n %% p } True }   sub powerful (\n, \k = 2) { my @p; p(1, 2*k - 1); sub p (\m, \r) { @p.push(m) and return if r < k; for 1 .. ...
http://rosettacode.org/wiki/Aliquot_sequence_classifications
Aliquot sequence classifications
An aliquot sequence of a positive integer K is defined recursively as the first member being K and subsequent members being the sum of the Proper divisors of the previous term. If the terms eventually reach 0 then the series for K is said to terminate. There are several classifications for non termination: If the s...
#J
J
proper_divisors=: [: */@>@}:@,@{ [: (^ i.@>:)&.>/ 2 p: x: aliquot=: +/@proper_divisors ::0: rc_aliquot_sequence=: aliquot^:(i.16)&> rc_classify=: 3 :0 if. 16 ~:# y do. ' invalid ' elseif. 6 > {: y do. ' terminate ' elseif. (+./y>2^47) +. 16 = #~.y do. ' non-terminat...
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#PHP
PHP
class E {};   $e=new E();   $e->foo=1;   $e->{"foo"} = 1; // using a runtime name $x = "foo"; $e->$x = 1; // using a runtime name in a variable
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#PicoLisp
PicoLisp
: (setq MyObject (new '(+MyClass))) # Create some object -> $385605941 : (put MyObject 'newvar '(some value)) # Set variable -> (some value) : (show MyObject) # Show the object $385605941 (+MyClass) newvar (some value) -> $385605941
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Pike
Pike
class CSV { mapping variables = ([]);   mixed `->(string name) { return variables[name]; }   void `->=(string name, mixed value) { variables[name] = value; }   array _indices() { return indices(variables); } }   object csv = CSV(); csv->greeting = "hello w...
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#PL.2FM
PL/M
100H: /* THERE IS NO STANDARD LIBRARY THIS DEFINES SOME BASIC I/O USING CP/M */ BDOS: PROCEDURE (F,A); DECLARE F BYTE, A ADDRESS; GO TO 5; END BDOS; EXIT: PROCEDURE; CALL BDOS(0,0); END EXIT; PUT$CHAR: PROCEDURE (C); DECLARE C BYTE; CALL BDOS(2,C); END PUT$CHAR; PRINT: PROCEDURE (S); DECLARE S ADDRESS; CALL BDOS(9,S...
http://rosettacode.org/wiki/AKS_test_for_primes
AKS test for primes
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles. The theorem on which the test is based can be stated as follows:   a number   p {\displaystyle p}   is prime   if and only if   all the coefficients of the polynomial ...
#Elena
Elena
import extensions;   singleton AksTest { static long[] c := new long[](100);   coef(int n) { int i := 0; int j := 0;   if ((n < 0) || (n > 63)) { AbortException.raise() }; // gracefully deal with range issue   c[i] := 1l; for (int i := 0, i < n, i += 1) { ...
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#J
J
(#~ 1 p: [:+/@|: 10&#.inv) i.&.(p:inv) 500 2 3 5 7 11 23 29 41 43 47 61 67 83 89 101 113 131 137 139 151 157 173 179 191 193 197 199 223 227 229 241 263 269 281 283 311 313 317 331 337 353 359 373 379 397 401 409 421 443 449 461 463 467 487
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#Java
Java
public class additivePrimes {   public static void main(String[] args) { int additive_primes = 0; for (int i = 2; i < 500; i++) { if(isPrime(i) && isPrime(digitSum(i))){ additive_primes++; System.out.print(i + " "); } } System.o...
http://rosettacode.org/wiki/Almost_prime
Almost prime
A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   where   k = 2 {\displaystyl...
#Java
Java
public class AlmostPrime { public static void main(String[] args) { for (int k = 1; k <= 5; k++) { System.out.print("k = " + k + ":");   for (int i = 2, c = 0; c < 10; i++) { if (kprime(i, k)) { System.out.print(" " + i); c++; ...
http://rosettacode.org/wiki/Anagrams
Anagrams
When two or more words are composed of the same characters, but in a different order, they are called anagrams. Task[edit] Using the word list at   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, find the sets of words that share the same characters that contain the most words in them. Related tasks Word plays ...
#Delphi
Delphi
  program AnagramsTest;   {$APPTYPE CONSOLE}   {$R *.res}   uses System.SysUtils, System.Classes, System.Diagnostics;   function Sort(s: string): string; var c: Char; i, j, aLength: Integer; begin aLength := s.Length;   if aLength = 0 then exit('');   Result := s;   for i := 1 to aLength - 1 do ...
http://rosettacode.org/wiki/Angle_difference_between_two_bearings
Angle difference between two bearings
Finding the angle between two bearings is often confusing.[1] Task Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings. Input bearings are expressed in the range   -180   to   +180   degrees. The  result  is also expressed in the range   -180   to   +180   degrees. ...
#Python
Python
from __future__ import print_function   def getDifference(b1, b2): r = (b2 - b1) % 360.0 # Python modulus has same sign as divisor, which is positive here, # so no need to consider negative case if r >= 180.0: r -= 360.0 return r   if __name__ == "__main__": print ("Input in -180 to +180 range") print (getDiff...
http://rosettacode.org/wiki/Anagrams/Deranged_anagrams
Anagrams/Deranged anagrams
Two or more words are said to be anagrams if they have the same characters, but in a different order. By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words. Task[edit] Use the word list at uni...
#REXX
REXX
/*REXX program finds the largest deranged word (within an identified dictionary). */ iFID= 'unixdict.txt'; words=0 /*input file ID; number of words so far*/ wL.=0 /*number of words of length L. so far*/ do while lines(iFID)\==0 ...
http://rosettacode.org/wiki/Anonymous_recursion
Anonymous recursion
While implementing a recursive function, it often happens that we must resort to a separate   helper function   to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects,   and/or the f...
#PARI.2FGP
PARI/GP
Fib(n)={ my(F=(k,f)->if(k<2,k,f(k-1,f)+f(k-2,f))); if(n<0,(-1)^(n+1),1)*F(abs(n),F) };
http://rosettacode.org/wiki/Amicable_pairs
Amicable pairs
Two integers N {\displaystyle N} and M {\displaystyle M} are said to be amicable pairs if N ≠ M {\displaystyle N\neq M} and the sum of the proper divisors of N {\displaystyle N} ( s u m ( p r o p D i v s ( N ) ) {\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))} ) = M ...
#Oforth
Oforth
import: mapping   Integer method: properDivs -- [] #[ self swap mod 0 == ] self 2 / seq filter ;   : amicables | i j | Array new 20000 loop: i [ i properDivs sum dup ->j i <= if continue then j properDivs sum i <> if continue then [ i, j ] over add ] ;
http://rosettacode.org/wiki/Animate_a_pendulum
Animate a pendulum
One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display. The classic such physical system is a simple gravity pendulum. Task Create a simple physical model of a pendulum and animate it.
#QB64
QB64
'declare and initialize variables CONST PI = 3.141592   DIM SHARED Bob_X, Bob_Y, Pivot_X, Pivot_Y, Rod_Length, Rod_Angle, Bob_Angular_Acceleration, Bob_Angular_Velocity, Delta_Time, Drawing_Scale, G AS DOUBLE DIM SHARED exit_flag AS INTEGER   'set gravity to Earth's by default (in m/s squared) G = -9.80665   'set the p...
http://rosettacode.org/wiki/Amb
Amb
Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"). The Amb operator takes a v...
#J
J
amb=. ([ , ' ' , ])&>/&.>@:((({:@:[ = {.@:])&>/&> # ])@:,@:({@(,&<))) >@(amb&.>/) ('the';'that';'a');('frog';'elephant';'thing');('walked';'treaded';'grows');(<'slowly';'quickly') +-----------------------+ |that thing grows slowly| +-----------------------+
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#BQN
BQN
Acc ← { 𝕊 sum: {sum+↩𝕩} } x ← Acc 1 X 5 Acc 3 X 2.3
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#C
C
#include <stdio.h> //~ Take a number n and return a function that takes a number i #define ACCUMULATOR(name,n) __typeof__(n) name (__typeof__(n) i) { \ static __typeof__(n) _n=n; LOGIC; } //~ have it return n incremented by the accumulation of i #define LOGIC return _n+=i ACCUMULATOR(x,1.0) ACCUMULATOR(y,3) ACCUMUL...
http://rosettacode.org/wiki/Ackermann_function
Ackermann function
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree. The Ackermann function is usually defined as follows: A ( m , n ) = { n + 1 if  m = 0 A ( m ...
#360_Assembly
360 Assembly
* Ackermann function 07/09/2015 &LAB XDECO &REG,&TARGET .*-----------------------------------------------------------------* .* THIS MACRO DISPLAYS THE REGISTER CONTENTS AS A TRUE * .* DECIMAL VALUE. XDECO IS NOT PART OF STANDARD S360 MACROS! * *--------------------------------------...
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications
Abundant, deficient and perfect number classifications
These define three classifications of positive integers based on their   proper divisors. Let   P(n)   be the sum of the proper divisors of   n   where the proper divisors are all positive divisors of   n   other than   n   itself. if P(n) < n then n is classed as deficient (OEIS A005100). if P(n)...
#Action.21
Action!
PROC FillSumOfDivisors(CARD ARRAY pds CARD size,maxNum,offset) CARD i,j   FOR i=0 TO size-1 DO pds(i)=1 OD FOR i=2 TO maxNum DO FOR j=i+i TO maxNum STEP i DO IF j>=offset THEN pds(j-offset)==+i FI OD OD RETURN   PROC Main() DEFINE MAXNUM="20000" DEFINE HALFNUM="10000"...
http://rosettacode.org/wiki/Align_columns
Align columns
Given a text file of many lines, where fields within a line are delineated by a single 'dollar' character, write a program that aligns each column of fields by ensuring that words in each column are separated by at least one space. Further, allow for each word in a column to be either left justified, right justified, o...
#AppleScript
AppleScript
-- COLUMN ALIGNMENTS ---------------------------------------------------------   property pstrLines : ¬ "Given$a$text$file$of$many$lines,$where$fields$within$a$line$\n" & ¬ "are$delineated$by$a$single$'dollar'$character,$write$a$program\n" & ¬ "that$aligns$each$column$of$fields$by$ensuring$that$words$in$eac...
http://rosettacode.org/wiki/Active_object
Active object
In object-oriented programming an object is active when its state depends on clock. Usually an active object encapsulates a task that updates the object's state. To the outer world the object looks like a normal object with methods that can be called from outside. Implementation of such methods must have a certain sync...
#EchoLisp
EchoLisp
  (require 'timer)   ;; returns an 'object' : (&lamdba; message [values]) ;; messages : input, output, sample, inspect (define (make-active) (let [ (t0 #f) (dt 0) (t 0) (Kt 0) ; K(t) (S 0) (K 0)] (lambda (message . args) (case message ((output) (// S 2)) ((input ) (set! K (car args)) (set! t0 #f)...
http://rosettacode.org/wiki/Achilles_numbers
Achilles numbers
This page uses content from Wikipedia. The original article was at Achilles number. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) An Achilles number is a number that is powerful but imperfect. Na...
#Rust
Rust
fn perfect_powers(n: u128) -> Vec<u128> { let mut powers = Vec::<u128>::new(); let sqrt = (n as f64).sqrt() as u128; for i in 2..=sqrt { let mut p = i * i; while p < n { powers.push(p); p *= i; } } powers.sort(); powers.dedup(); powers }   fn b...
http://rosettacode.org/wiki/Achilles_numbers
Achilles numbers
This page uses content from Wikipedia. The original article was at Achilles number. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) An Achilles number is a number that is powerful but imperfect. Na...
#Wren
Wren
import "./math" for Int import "./seq" for Lst import "./fmt" for Fmt   var maxDigits = 8 var limit = 10.pow(maxDigits) var c = Int.primeSieve(limit-1, false)   var totient = Fn.new { |n| var tot = n var i = 2 while (i*i <= n) { if (n%i == 0) { while(n%i == 0) n = (n/i).floor ...
http://rosettacode.org/wiki/Aliquot_sequence_classifications
Aliquot sequence classifications
An aliquot sequence of a positive integer K is defined recursively as the first member being K and subsequent members being the sum of the Proper divisors of the previous term. If the terms eventually reach 0 then the series for K is said to terminate. There are several classifications for non termination: If the s...
#Java
Java
import java.util.ArrayList; import java.util.Arrays; import java.util.List; import java.util.stream.LongStream;   public class AliquotSequenceClassifications {   private static Long properDivsSum(long n) { return LongStream.rangeClosed(1, (n + 1) / 2).filter(i -> n % i == 0 && n != i).sum(); }   sta...
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Pop11
Pop11
lib objectclass;   define :class foo; enddefine;   define define_named_method(method, class); lvars method_str = method >< ''; lvars class_str = class >< ''; lvars method_hash_str = 'hash_' >< length(class_str) >< '_' >< class_str >< '_' >< length(method_str) ...
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#PowerShell
PowerShell
$x = 42 ` | Add-Member -PassThru ` NoteProperty ` Title ` "The answer to the question about life, the universe and everything"
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Python
Python
class empty(object): pass e = empty()
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime
Add a variable to a class instance at runtime
Demonstrate how to dynamically add variables to an object (a class instance) at runtime. This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re...
#Raku
Raku
class Bar { } # an empty class   my $object = Bar.new; # new instance   role a_role { # role to add a variable: foo, has $.foo is rw = 2; # with an initial value of 2 }   $object does a_role; # compose in the role   say $object.foo; # prints: 2 $object.foo = 5; # ...
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#PowerBASIC
PowerBASIC
'get a variable's address: DIM x AS INTEGER, y AS LONG y = VARPTR(x)   'can't set the address of a single variable, but can access memory locations DIM z AS INTEGER z = PEEK(INTEGER, y)   'or can do it one byte at a time DIM zz(1) AS BYTE zz(0) = PEEK(BYTE, y) zz(1) = PEEK(BYTE, y + 1) '(MAK creates an INTEGER, LONG, o...
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#PureBasic
PureBasic
a.i = 5 MessageRequester("Address",Str(@a))
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#Python
Python
foo = object() # Create (instantiate) an empty object address = id(foo)
http://rosettacode.org/wiki/Address_of_a_variable
Address of a variable
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#QB64
QB64
  ' Adapted from QB64wiki example a demo of _MEM type data and _MEM functions Type points x As Integer y As Integer z As Integer End Type   Dim Shared m(3) As _MEM Dim Shared Saved As points, first As points   m(1) = _Mem(first.x) m(2) = _Mem(first.y) m(3) = _Mem(first.z)   print "QB64 way to manage address...
http://rosettacode.org/wiki/AKS_test_for_primes
AKS test for primes
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles. The theorem on which the test is based can be stated as follows:   a number   p {\displaystyle p}   is prime   if and only if   all the coefficients of the polynomial ...
#Elixir
Elixir
defmodule AKS do def iterate(f, x), do: fn -> [x | iterate(f, f.(x))] end   def take(0, _lazy), do: [] def take(n, lazy) do [value | next] = lazy.() [value | take(n-1, next)] end   def pascal, do: iterate(fn row -> [1 | sum_adj(row)] end, [1])   defp sum_adj([_] = l), do: l defp sum_adj([a, b | _]...
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#jq
jq
def is_prime: . as $n | if ($n < 2) then false elif ($n % 2 == 0) then $n == 2 elif ($n % 3 == 0) then $n == 3 elif ($n % 5 == 0) then $n == 5 elif ($n % 7 == 0) then $n == 7 elif ($n % 11 == 0) then $n == 11 elif ($n % 13 == 0) then $n == 13 elif ($n % 17 == 0) then $n == 17...
http://rosettacode.org/wiki/Additive_primes
Additive primes
Definitions In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes. Task Write a program to determine (and show here) all additive primes less than 500. Optionally, show the number of additive primes. Also see   the OEIS entry:   A046704 additive primes.   ...
#Haskell
Haskell
import Data.List (unfoldr)   -- infinite list of primes primes = 2 : sieve [3,5..] where sieve (x:xs) = x : sieve (filter (\y -> y `mod` x /= 0) xs)   -- primarity test, effective for numbers less then billion isPrime n = all (\p -> n `mod` p /= 0) $ takeWhile (< sqrtN) primes where sqrtN = round . sqrt . fromInteg...
http://rosettacode.org/wiki/Almost_prime
Almost prime
A   k-Almost-prime   is a natural number   n {\displaystyle n}   that is the product of   k {\displaystyle k}   (possibly identical) primes. Example 1-almost-primes,   where   k = 1 {\displaystyle k=1} ,   are the prime numbers themselves. 2-almost-primes,   where   k = 2 {\displaystyl...
#JavaScript
JavaScript
function almostPrime (n, k) { var divisor = 2, count = 0 while(count < k + 1 && n != 1) { if (n % divisor == 0) { n = n / divisor count = count + 1 } else { divisor++ } } return count == k }   for (var k = 1; k <= 5; k++) { document.write("...
http://rosettacode.org/wiki/Anagrams
Anagrams
When two or more words are composed of the same characters, but in a different order, they are called anagrams. Task[edit] Using the word list at   http://wiki.puzzlers.org/pub/wordlists/unixdict.txt, find the sets of words that share the same characters that contain the most words in them. Related tasks Word plays ...
#E
E
println("Downloading...") when (def wordText := <http://wiki.puzzlers.org/pub/wordlists/unixdict.txt> <- getText()) -> { def words := wordText.split("\n")   def storage := [].asMap().diverge() def anagramTable extends storage { to get(key) { return storage.fetch(key, fn { storage[key] := [].diverge(...
http://rosettacode.org/wiki/Angle_difference_between_two_bearings
Angle difference between two bearings
Finding the angle between two bearings is often confusing.[1] Task Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings. Input bearings are expressed in the range   -180   to   +180   degrees. The  result  is also expressed in the range   -180   to   +180   degrees. ...
#Quackery
Quackery
[ $ "bigrat.qky" loadfile ] now!   [ v- -v proper rot 360 mod unrot improper 180 1 2over v< iff [ 360 1 v- ] done 2dup -180 1 v< if [ 360 1 v+ ] ] is angledelta ( n/d n/d --> n/d )   ' [ [ $ "20" $ "45" ] [ $ "-45" $ ...
http://rosettacode.org/wiki/Angle_difference_between_two_bearings
Angle difference between two bearings
Finding the angle between two bearings is often confusing.[1] Task Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings. Input bearings are expressed in the range   -180   to   +180   degrees. The  result  is also expressed in the range   -180   to   +180   degrees. ...
#Racket
Racket
#lang racket (define (% a b) (- a (* b (truncate (/ a b)))))   (define (bearing- bearing heading) (- (% (+ (% (- bearing heading) 360) 540) 360) 180))   (module+ main (bearing- 20 45) (bearing- -45 45) (bearing- -85 90) (bearing- -95 90) (bearing- -45 125) (bearing- -45 145) (bearing- 29.4803 -88.6381) ...
http://rosettacode.org/wiki/Anagrams/Deranged_anagrams
Anagrams/Deranged anagrams
Two or more words are said to be anagrams if they have the same characters, but in a different order. By analogy with derangements we define a deranged anagram as two words with the same characters, but in which the same character does not appear in the same position in both words. Task[edit] Use the word list at uni...
#Ring
Ring
# Project : Anagrams/Deranged anagrams   load "stdlib.ring" fn1 = "unixdict.txt"   fp = fopen(fn1,"r") str = fread(fp, getFileSize(fp)) fclose(fp) strlist = str2list(str) anagram = newlist(len(strlist), 5) anag = list(len(strlist)) result = list(len(strlist)) for x = 1 to len(result) result[x] = 0 next for x = 1 ...
http://rosettacode.org/wiki/Anonymous_recursion
Anonymous recursion
While implementing a recursive function, it often happens that we must resort to a separate   helper function   to handle the actual recursion. This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects,   and/or the f...
#Pascal
Pascal
  program AnonymousRecursion;   function Fib(X: Integer): integer;   function DoFib(N: Integer): Integer; begin if N < 2 then DoFib:=N else DoFib:=DoFib(N-1) + DoFib(N-2); end;   begin if X < 0 then Fib:=X else Fib:=DoFib(X); end;     var I,V: integer;   begin for I:=-1 to 15 do begin V:=Fib(I); Write(I:3,' - '...
http://rosettacode.org/wiki/Amicable_pairs
Amicable pairs
Two integers N {\displaystyle N} and M {\displaystyle M} are said to be amicable pairs if N ≠ M {\displaystyle N\neq M} and the sum of the proper divisors of N {\displaystyle N} ( s u m ( p r o p D i v s ( N ) ) {\displaystyle \mathrm {sum} (\mathrm {propDivs} (N))} ) = M ...
#OCaml
OCaml
let rec isqrt n = if n = 1 then 1 else let _n = isqrt (n - 1) in (_n + (n / _n)) / 2   let sum_divs n = let sum = ref 1 in for d = 2 to isqrt n do if (n mod d) = 0 then sum := !sum + (n / d + d); done; !sum   let () = for n = 2 to 20000 do let m = sum_divs n in if (m > n) then if (su...
http://rosettacode.org/wiki/Animate_a_pendulum
Animate a pendulum
One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display. The classic such physical system is a simple gravity pendulum. Task Create a simple physical model of a pendulum and animate it.
#R
R
library(DescTools)   pendulum<-function(length=5,radius=1,circle.color="white",bg.color="white"){ tseq = c(seq(0,pi,by=.1),seq(pi,0,by=-.1)) slow=.27;fast=.07 sseq = c(seq(slow,fast,length.out = length(tseq)/4),seq(fast,slow,length.out = length(tseq)/4),seq(slow,fast,length.out = length(tseq)/4),seq(fast,slow,len...
http://rosettacode.org/wiki/Amb
Amb
Define and give an example of the Amb operator. The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"). The Amb operator takes a v...
#JavaScript
JavaScript
function ambRun(func) { var choices = []; var index;   function amb(values) { if (values.length == 0) { fail(); } if (index == choices.length) { choices.push({i: 0, count: values.length}); } var choice = choices[index+...
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#C.23
C#
using System;   class Program { static Func<dynamic, dynamic> Foo(dynamic n) { return i => n += i; }   static void Main(string[] args) { var x = Foo(1); x(5); Foo(3); Console.WriteLine(x(2.3)); } }
http://rosettacode.org/wiki/Accumulator_factory
Accumulator factory
A problem posed by Paul Graham is that of creating a function that takes a single (numeric) argument and which returns another function that is an accumulator. The returned accumulator function in turn also takes a single numeric argument, and returns the sum of all the numeric values passed in so far to that accumulat...
#C.2B.2B
C++
#include <iostream>   class Acc { public: Acc(int init) : _type(intType) , _intVal(init) {}   Acc(float init) : _type(floatType) , _floatVal(init) {}   int operator()(int x) { if( _type == intType ) { _intVal += x; return _i...
http://rosettacode.org/wiki/Ackermann_function
Ackermann function
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree. The Ackermann function is usually defined as follows: A ( m , n ) = { n + 1 if  m = 0 A ( m ...
#68000_Assembly
68000 Assembly
; ; Ackermann function for Motorola 68000 under AmigaOs 2+ by Thorham ; ; Set stack space to 60000 for m = 3, n = 5. ; ; The program will print the ackermann values for the range m = 0..3, n = 0..5 ; _LVOOpenLibrary equ -552 _LVOCloseLibrary equ -414 _LVOVPrintf equ -954   m equ 3 ; Nr of iterations for the main loop. ...
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications
Abundant, deficient and perfect number classifications
These define three classifications of positive integers based on their   proper divisors. Let   P(n)   be the sum of the proper divisors of   n   where the proper divisors are all positive divisors of   n   other than   n   itself. if P(n) < n then n is classed as deficient (OEIS A005100). if P(n)...
#Ada
Ada
with Ada.Text_IO, Generic_Divisors;   procedure ADB_Classification is function Same(P: Positive) return Positive is (P); package Divisor_Sum is new Generic_Divisors (Result_Type => Natural, None => 0, One => Same, Add => "+");   type Class_Type is (Deficient, Perfect, Abundant);   function Class(D_...
http://rosettacode.org/wiki/Align_columns
Align columns
Given a text file of many lines, where fields within a line are delineated by a single 'dollar' character, write a program that aligns each column of fields by ensuring that words in each column are separated by at least one space. Further, allow for each word in a column to be either left justified, right justified, o...
#ARM_Assembly
ARM Assembly
  /* ARM assembly Raspberry PI */ /* program alignColumn.s */   /* REMARK 1 : this program use routines in a include file see task Include a file language arm assembly for the routine affichageMess conversion10 see at end of this program the instruction include */ /* for constantes see task include a...
http://rosettacode.org/wiki/Active_object
Active object
In object-oriented programming an object is active when its state depends on clock. Usually an active object encapsulates a task that updates the object's state. To the outer world the object looks like a normal object with methods that can be called from outside. Implementation of such methods must have a certain sync...
#Erlang
Erlang
  -module( active_object ). -export( [delete/1, input/2, new/0, output/1, task/1] ). -compile({no_auto_import,[time/0]}).   delete( Object ) -> Object ! stop.   input( Object, Fun ) -> Object ! {input, Fun}.   new( ) -> K = fun zero/1, S = 0, T0 = seconds_with_decimals(), erlang:spaw...