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http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#jq
jq
# input should be an array of the lengths of the sides def hero: (add/2) as $s | ($s*($s - .[0])*($s - .[1])*($s - .[2])) as $a2 | if $a2 > 0 then ($a2 | sqrt) else 0 end;   def is_heronian: hero as $h | $h > 0 and ($h|floor) == $h;   def gcd3(x; y; z): # subfunction expects [a,b] as input def rgcd: i...
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#Julia
Julia
  type IntegerTriangle{T<:Integer} a::T b::T c::T p::T σ::T end   function IntegerTriangle{T<:Integer}(a::T, b::T, c::T) p = a + b + c s = div(p, 2) σ = isqrt(s*(s-a)*(s-b)*(s-c)) (x, y, z) = sort([a, b, c]) IntegerTriangle(x, y, z, p, σ) end   function isprimheronian{T<:Integer}...
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#CLU
CLU
% Functions can be passed to other functions using the 'proctype' % type generator. The same works for iterators, using 'itertype'   % Here are two functions square = proc (n: int) returns (int) return (n*n) end square cube = proc (n: int) returns (int) return (n*n*n) end cube   % Here is a function that takes another ...
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Objeck
Objeck
  use Net; use Concurrency;   bundle Default { class GoodByeWorld { function : Main(args : String[]) ~ Nil { server := TCPSocketServer->New(8080); if(server->Listen(5)) { while(true) { client := server->Accept(); client->WriteString("<html>\n<body>\nGoodbye, world!\n</body>...
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#OCaml
OCaml
let try_finalise f x finally y = let res = try f x with e -> finally y; raise e in finally y; res   let rec restart_on_EINTR f x = try f x with Unix.Unix_error (Unix.EINTR, _, _) -> restart_on_EINTR f x   let double_fork_treatment server service (client_descr, _ as client) = let treat () = match Unix.fork...
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#XSLT
XSLT
<?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0"> <xsl:output method="text"/>   <xsl:template match="/"> <![CDATA[   This text is in a CDATA section. In here, it's okay to include <, >, &, ", and ' without any special treatment.   The section is termi...
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Yabasic
Yabasic
  text1$ = "Esta es la primera linea. Esta es la segunda linea. Esta \"linea\" contiene comillas.\n"   text2$ = "Blast it James! I'm a magician, not a doctor! --- L. McCoy\n"     print text1$ print text2$ end  
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#zkl
zkl
x:= #<<< "#<<< starts a block of lines that are concatenated verbatim and fed into the parser as one line. #<<< ends the block. Both #<<< tokens must start the line that is otherwise ignored   Note that is isn't a string, but arbitrary source " + 1 + 23; #<<< x.println();
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#REXX
REXX
/*REXX program calculates and verifies the Hofstadter Figure─Figure sequences. */ parse arg x top bot . /*obtain optional arguments from the CL*/ if x=='' | x=="," then x= 10 /*Not specified? Then use the default.*/ if top=='' | top=="," then top=1000 ...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#PHP
PHP
<?php function horner($coeff, $x) { $result = 0; foreach (array_reverse($coeff) as $c) $result = $result * $x + $c; return $result; }   $coeff = array(-19.0, 7, -4, 6); $x = 3; echo horner($coeff, $x), "\n"; ?>
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Picat
Picat
horner([],_X,0). horner([H|T],X,V) :- horner(T,X,V1), V = V1 * X + H.
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Seed7
Seed7
$ include "seed7_05.s7i"; include "draw.s7i"; include "keybd.s7i";   const integer: delta is 8;   const proc: drawDown (inout integer: x, inout integer: y, in integer: n) is forward; const proc: drawUp (inout integer: x, inout integer: y, in integer: n) is forward;   const proc: drawRight (inout integer: x, inout i...
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Sidef
Sidef
require('Image::Magick')   class Turtle( x = 500, y = 500, angle = 0, scale = 1, mirror = 1, xoff = 0, yoff = 0, color = 'black', ) {   has im = %O<Image::Magick>.new(size => "#{x}x#{y}")   method init { angle.deg2rad! im.ReadImage('canvas:white')...
http://rosettacode.org/wiki/Holidays_related_to_Easter
Holidays related to Easter
Task Calculate the dates of:   Easter   Ascension Thursday   Pentecost   Trinity Sunday   Corpus Christi feast (for Catholic)   All Saints' Sunday (for Orthodox) As an example, calculate for the first year of each century from;   years     400   to   2100 CE   and for   years   2010   to   2020 CE. Note ...
#Phix
Phix
-- demo\rosetta\Easter.exw function easter(integer year) -- from https://en.wikipedia.org/wiki/Computus#Anonymous_Gregorian_algorithm integer a = mod(year,19), b = floor(year/100), c = mod(year,100), d = floor(b/4), e = mod(b,4), f = floor((b+8)/25), ...
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#PureBasic
PureBasic
If OpenConsole() Define.f lat, slat, lng, ref Define.i h Print("Enter latitude => "): lat=ValF(Input()) Print("Enter longitude => "): lng=ValF(Input()) Print("Enter legal meridian => "): ref=ValF(Input()) PrintN("")   slat=Sin(lat*2*#PI/360) PrintN(" sine of latitude: "+StrF(slat,3)) P...
http://rosettacode.org/wiki/Huffman_coding
Huffman coding
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols. For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi...
#Red
Red
Red [file: %huffy.red]   ;; message to encode: msg: "this is an example for huffman encoding"   ;;map to collect leave knots per uniq character of message m: make map! []   knot: make object! [ left: right: none  ;; pointer to left/right sibling code: none  ;; first holds char for debugging, later binary co...
http://rosettacode.org/wiki/Identity_matrix
Identity matrix
Task Build an   identity matrix   of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...
#TypeScript
TypeScript
  function identity(n) { if (n < 1) return "Not defined"; else if (n == 1) return 1; else { var idMatrix:number[][]; for (var i: number = 0; i < n; i++) { for (var j: number = 0; j < n; j++) { if (i != j) idMatrix[i][j] = 0; else idMatrix[i][j] = 1...
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
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 |...
#TI-89_BASIC
TI-89 BASIC
Local a, b, result Prompt a, b If a < b Then "<" → result ElseIf a = b Then "=" → result ElseIf a > b Then ">" → result Else "???" → result EndIf Disp string(a) & " " & result & " " & string(b)
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Liberty_BASIC
Liberty BASIC
  result = DownloadToFile( "http://rosettacode.org/wiki/Main_Page", "in.html") timer 2000, [on] wait [on] timer 0 if result <> 0 then print "Error downloading."   end   Function DownloadToFile( urlfile$, localfile$) open "URLmon" for dll as #url calldll #url, "URLDownloadToFileA",_ 0 as long,_ 'null...
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#Phix
Phix
with javascript_semantics sequence a = {1,1} function q(integer n) for l=length(a)+1 to n do a &= a[a[l-1]]+a[l-a[l-1]] end for return a[n] end function integer mallows = -1, max_n for p=0 to 19 do atom max_an = 0.5 integer l = power(2,p), h=l*2 for n=l to h do atom an = q(n)...
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Metafont
Metafont
errmessage "Error"; message "...going on..."; % if the user decides to go on and not to stop  % the program because of the error.
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#ML.2FI
ML/I
MCSET S4=1 MCNOTE Goodbye, World!
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Modula-2
Modula-2
MODULE HelloErr; IMPORT StdError;   BEGIN StdError.WriteString('Goodbye, World!'); StdError.WriteLn END HelloErr.
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Modula-3
Modula-3
MODULE Stderr EXPORTS Main;   IMPORT Wr, Stdio;   BEGIN Wr.PutText(Stdio.stderr, "Goodbye, World!\n"); END Stderr.
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#Icon_and_Unicon
Icon and Unicon
link printf   procedure main()   V := [1, 1, 2, 3, 3, 4, 5, 5, 6, 6] every i := 1 to *V do if Q(i) ~= V[i] then stop("Assertion failure for position ",i) printf("Q(1 to %d) - verified.\n",*V)   q := Q(n := 1000) v := 502 printf("Q[%d]=%d - %s.\n",n,v,if q = v then "verified" else "failed")   invcount := 0 every i :...
http://rosettacode.org/wiki/Hello_world/Text
Hello world/Text
Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error   Hello world/Web server
#Agena
Agena
print( "Hello world!" )
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#Kotlin
Kotlin
import java.util.ArrayList   object Heron { private val n = 200   fun run() { val l = ArrayList<IntArray>() for (c in 1..n) for (b in 1..c) for (a in 1..b) if (gcd(gcd(a, b), c) == 1) { val p = a + b + c ...
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#CoffeeScript
CoffeeScript
double = [1,2,3].map (x) -> x*2
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Ol
Ol
(import (lib http))   (http:run 8080 (lambda (fd request headers send close) (send "HTTP/1.0 200 OK\n" "Connection: close\n" "Content-Type: text/html; charset=UTF-8\n" "Server: " (car *version*) "/" (cdr *version*) "\n\n"   "<h1>Goodbye, World!</h1>" (ref request...
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Opa
Opa
server = one_page_server("Hello", -> <>Goodbye, world</>)
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#Ring
Ring
  # Project : Hofstadter Figure-Figure sequences   hofr = list(20) hofr[1] = 1 hofs = [] add(hofs,2) for n = 1 to 10 hofr[n+1] = hofr[n] + hofs[n] if n = 1 add(hofs,4) else for p = hofr[n] + 1 to hofr[n+1] - 1 if p != hofs[n] add(hofs,p) ...
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#Ruby
Ruby
$r = [nil, 1] $s = [nil, 2]   def buildSeq(n) current = [ $r[-1], $s[-1] ].max while $r.length <= n || $s.length <= n idx = [ $r.length, $s.length ].min - 1 current += 1 if current == $r[idx] + $s[idx] $r << current else $s << current end end end   def ffr(n) buildSeq(n) $r[n] ...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#PicoLisp
PicoLisp
(de horner (Coeffs X) (let Res 0 (for C (reverse Coeffs) (setq Res (+ C (* X Res))) ) ) )
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#PL.2FI
PL/I
  declare (i, n) fixed binary, (x, value) float; /* 11 May 2010 */ get (x); get (n); begin; declare a(0:n) float; get list (a); value = a(n); do i = n to 1 by -1; value = value*x + a(i-1); end; put (value); end;  
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Vala
Vala
struct Point{ int x; int y; Point(int px,int py){ x=px; y=py; } }   public class Hilbert : Gtk.DrawingArea {   private int it = 1; private Point[] points; private const int WINSIZE = 300;   public Hilbert() { set_size_request(WINSIZE, WINSIZE); }   public ...
http://rosettacode.org/wiki/Holidays_related_to_Easter
Holidays related to Easter
Task Calculate the dates of:   Easter   Ascension Thursday   Pentecost   Trinity Sunday   Corpus Christi feast (for Catholic)   All Saints' Sunday (for Orthodox) As an example, calculate for the first year of each century from;   years     400   to   2100 CE   and for   years   2010   to   2020 CE. Note ...
#PicoLisp
PicoLisp
(load "@lib/cal.l") # For 'easter' function   (de dayMon (Dat) (let D (date Dat) (list (day Dat *Day) " " (align 2 (caddr D)) " " (get *Mon (cadr D))) ) )   (for Y (append (range 400 2100 100) (range 2010 2020)) (let E (easter Y) (prinl (align 4 Y) " Easter: " (dayMon E) ",...
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#Python
Python
from __future__ import print_function import math try: raw_input except: raw_input = input   lat = float(raw_input("Enter latitude => ")) lng = float(raw_input("Enter longitude => ")) ref = float(raw_input("Enter legal meridian => ")) print()   slat = math.sin(math.radians(lat)) print(" sine of latitude: ...
http://rosettacode.org/wiki/Huffman_coding
Huffman coding
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols. For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi...
#REXX
REXX
/* REXX --------------------------------------------------------------- * 27.12.2013 Walter Pachl * 29.12.2013 -"- changed for test of s=xrange('00'x,'ff'x) * 14.03.2018 -"- use format instead of right to diagnose size poblems * Stem m contains eventually the following node data * m.i.0id Node id * m.i.0c character * ...
http://rosettacode.org/wiki/Identity_matrix
Identity matrix
Task Build an   identity matrix   of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...
#Vala
Vala
int main (string[] args) { if (args.length < 2) { print ("Please, input an integer > 0.\n"); return 0; } var n = int.parse (args[1]); if (n <= 0) { print ("Please, input an integer > 0.\n"); return 0; } int[,] array = new int[n, n]; for (var i = 0; i < n; i ++) { for (var j = 0; j < n; j ++) { if (i...
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
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 |...
#Toka
Toka
[ ( a b -- ) 2dup < [ ." a is less than b\n" ] ifTrue 2dup > [ ." a is greater than b\n" ] ifTrue = [ ." a is equal to b\n" ] ifTrue ] is compare-integers   1 1 compare-integers 2 1 compare-integers 1 2 compare-integers
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
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 |...
#TUSCRIPT
TUSCRIPT
  $$ MODE TUSCRIPT   ASK "Please enter your first integer:": i1="" ASK "Please enter your second integer:": i2=""   IF (i1!='digits'||i2!='digits') ERROR/STOP "Please insert digits"   IF (i1==i2) PRINT i1," is equal to ",i2 IF (i1<i2) PRINT i1," is less than ",i2 IF (i1>i2) PRINT i1," is greater than ",i2  
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Lingo
Lingo
property _netID property _cbHandler property _cbTarget   ---------------------------------------- -- Simple HTTP GET request -- @param {string} url -- @param {symbol} cbHandler -- @param {object} [cbTarget=_movie] ---------------------------------------- on new (me, url, cbHandler, cbTarget) if voidP(cbTarget) then c...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#LiveCode
LiveCode
put true into libURLFollowHttpRedirects get URL "http://httpbin.org/html" put it
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#Picat
Picat
go => foreach(N in 0..19) [Val,Ix] = argmax({a(I)/I : I in 2**N..2**(N+1)}), printf("Max from 2^%2d..2^%-2d is %0.8f at %d\n",N,N+1,Val,Ix+2**N-1) end, println(mallows_number=mallows_number()), nl.   % The sequence definition table a(1) = 1. a(2) = 1. a(N) = a(a(N-1))+a(N-a(N-1)).   % argmax: f...
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#PicoLisp
PicoLisp
(de hofcon (N) (cache '(NIL) N (if (>= 2 N) 1 (+ (hofcon (hofcon (dec N))) (hofcon (- N (hofcon (dec N)))) ) ) ) )   (scl 20)   (de sequence (M) (let (Lim 4 Max 0 4k$ 0) (for (N 3 (>= M N) (inc N)) (let V (*/ (hofcon N) 1.0 N) (setq Max ...
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#N.2Ft.2Froff
N/t/roff
  .tm Goodbye, World!  
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Neko
Neko
/** Hello world, to standard error, in Neko Tectonics: nekoc hello-stderr.neko neko hello-stderr */   /* Assume stderr is already open, just need write */ var file_write = $loader.loadprim("std@file_write", 4);   /* Load (and execute) the file_stderr primitive */ var stderr = $loader.loadprim("std@file_stde...
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Nemerle
Nemerle
System.Console.Error.WriteLine("Goodbye, World!");
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#IS-BASIC
IS-BASIC
100 PROGRAM "QSequen.bas" 110 LET LIMIT=1000 120 NUMERIC Q(1 TO LIMIT) 130 LET Q(1),Q(2)=1 140 FOR I=3 TO LIMIT 150 LET Q(I)=Q(I-Q(I-1))+Q(I-Q(I-2)) 160 NEXT 170 PRINT "First 10 terms:" 180 FOR I=1 TO 10 190 PRINT Q(I); 200 NEXT 210 PRINT :PRINT "Term 1000:";Q(1000)
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#J
J
Qs=:0 1 1 Q=: verb define n=. >./,y while. n>:#Qs do. Qs=: Qs,+/(-_2{.Qs){Qs end. y{Qs )
http://rosettacode.org/wiki/Hello_world/Text
Hello world/Text
Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error   Hello world/Web server
#Aime
Aime
o_text("Hello world!\n");
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#Lua
Lua
-- Returns the details of the Heronian Triangle with sides a, b, c or nil if it isn't one local function tryHt( a, b, c ) local result local s = ( a + b + c ) / 2; local areaSquared = s * ( s - a ) * ( s - b ) * ( s - c ); if areaSquared > 0 then -- a, b, c does form a triangle local are...
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#Common_Lisp
Common Lisp
CL-USER> (defun add (a b) (+ a b)) ADD CL-USER> (add 1 2) 3 CL-USER> (defun call-it (fn x y) (funcall fn x y)) CALL-IT CL-USER> (call-it #'add 1 2) 3
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Panda
Panda
8080.port.listen.say("Hello world!")
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Perl
Perl
use Socket;   my $port = 8080; my $protocol = getprotobyname( "tcp" );   socket( SOCK, PF_INET, SOCK_STREAM, $protocol ) or die "couldn't open a socket: $!"; # PF_INET to indicate that this socket will connect to the internet domain # SOCK_STREAM indicates a TCP stream, SOCK_DGRAM would indicate UDP communication  ...
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#Rust
Rust
  use std::collections::HashMap;   struct Hffs { sequence_r: HashMap<usize, usize>, sequence_s: HashMap<usize, usize>, }   impl Hffs { fn new() -> Hffs { Hffs { sequence_r: HashMap::new(), sequence_s: HashMap::new(), } } fn ffr(&mut self, n: usize) -> usize { ...
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#Scala
Scala
object HofstadterFigFigSeq extends App { import scala.collection.mutable.ListBuffer   val r = ListBuffer(0, 1) val s = ListBuffer(0, 2)   def ffr(n: Int): Int = { val ffri: Int => Unit = i => { val nrk = r.size - 1 val rNext = r(nrk)+s(nrk) r += rNext (r(nrk)+2 to rNext-1).foreach{s ...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Potion
Potion
horner = (x, coef) : result = 0 coef reverse each (a) : result = (result * x) + a . result .   horner(3, (-19, 7, -4, 6)) print
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#PowerShell
PowerShell
  function horner($coefficients, $x) { $accumulator = 0 foreach($i in ($coefficients.Count-1)..0){ $accumulator = ( $accumulator * $x ) + $coefficients[$i] } $accumulator } $coefficients = @(-19, 7, -4, 6) $x = 3 horner $coefficients $x  
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Visual_Basic_.NET
Visual Basic .NET
Imports System.Text   Module Module1   Sub Swap(Of T)(ByRef a As T, ByRef b As T) Dim c = a a = b b = c End Sub   Structure Point Dim x As Integer Dim y As Integer   'rotate/flip a quadrant appropriately Sub Rot(n As Integer, rx As Boolean, ry As Boole...
http://rosettacode.org/wiki/Holidays_related_to_Easter
Holidays related to Easter
Task Calculate the dates of:   Easter   Ascension Thursday   Pentecost   Trinity Sunday   Corpus Christi feast (for Catholic)   All Saints' Sunday (for Orthodox) As an example, calculate for the first year of each century from;   years     400   to   2100 CE   and for   years   2010   to   2020 CE. Note ...
#PL.2FI
PL/I
(subscriptrange, size, fofl): Easter: procedure options (main); declare months(12) character (9) varying static initial ( 'January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'); declare (year, month, day) fixe...
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#Racket
Racket
#lang racket   ;; print the table for a given latitude and longitude-offset, ;; given in degrees (define (print-table lat long-offset)  ;; print the table header (display (~a " sine of latitude: " (~r (sin (deg->rad lat)) #:precision '(= 3)) "\n" " diff longitude: " (~r long-o...
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#Raku
Raku
sub postfix:<°> ($a) { $a * pi / 180 } # degrees to radians sub postfix:<®> ($a) { $a * 180 / pi } # radians to degrees   my $latitude = prompt 'Enter latitude => '; my $longitude = prompt 'Enter longitude => '; my $meridian = prompt 'Enter legal meridian => ';   my $lat_sin = sin( $latitude° ); say 'Sine ...
http://rosettacode.org/wiki/Huffman_coding
Huffman coding
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols. For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi...
#Ruby
Ruby
require 'priority_queue'   def huffman_encoding(str) char_count = Hash.new(0) str.each_char {|c| char_count[c] += 1}   pq = CPriorityQueue.new # chars with fewest count have highest priority char_count.each {|char, count| pq.push(char, count)}   while pq.length > 1 key1, prio1 = pq.delete_min key2, ...
http://rosettacode.org/wiki/Identity_matrix
Identity matrix
Task Build an   identity matrix   of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...
#VBA
VBA
Private Function Identity(n As Integer) As Variant Dim I() As Integer ReDim I(n - 1, n - 1) For j = 0 To n - 1 I(j, j) = 1 Next j Identity = I End Function
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
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 |...
#UNIX_Shell
UNIX Shell
#!/bin/ksh # tested with ksh93s+   builtin printf   integer a=0 integer b=0   read a?"Enter value of a: " || { print -u2 "Input of a aborted." ; exit 1 ; } read b?"Enter value of b: " || { print -u2 "Input of b aborted." ; exit 1 ; }   if (( a < b )) ; then printf "%d is less than %d\n" a b fi if (( a == b )) ; the...
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
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 |...
#Ursa
Ursa
decl int first second out "enter first integer: " console set first (in int console) out "enter second integer: " console set second (in int console)   if (= first second) out "the two integers are equal" endl console end if if (< first second) out first " is less than " second endl console end if if (...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#LSL
LSL
string sURL = "http://www.RosettaCode.Org"; key kHttpRequestId; default { state_entry() { kHttpRequestId = llHTTPRequest(sURL, [], ""); } http_response(key kRequestId, integer iStatus, list lMetaData, string sBody) { if(kRequestId==kHttpRequestId) { llOwnerSay("Status="+(string)iStatus); integer x = 0; ...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Lua
Lua
  local http = require("socket.http") local url = require("socket.url") local page = http.request('http://www.google.com/m/search?q=' .. url.escape("lua")) print(page)  
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#PL.2FI
PL/I
  /* First part: */   declare L (10000) fixed static initial ((1000) 0); L(1), L(2) = 1; do i = 3 to 10000; k = L(i); L(i) = L(i-k) + L(1+k); end;  
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#Python
Python
from __future__ import division   def maxandmallows(nmaxpower2): nmax = 2**nmaxpower2 mx = (0.5, 2) mxpow2 = [] mallows = None   # Hofstadter-Conway sequence starts at hc[1], # hc[0] is not part of the series. hc = [None, 1, 1]   for n in range(2, nmax + 1): ratio = hc[n] / n ...
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#NetRexx
NetRexx
/* NetRexx */   options replace format comments java crossref savelog symbols binary   System.err.println("Goodbye, World!")  
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Nim
Nim
stderr.writeln "Hello World"
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Oberon-2
Oberon-2
  MODULE HelloErr; IMPORT Err; BEGIN Err.String("Goodbye, World!");Err.Ln END HelloErr.  
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Objective-C
Objective-C
#import <Foundation/Foundation.h>   int main() { fprintf(stderr, "Goodbye, World!\n"); fputs("Goodbye, World!\n", stderr); NSLog(@"Goodbye, World!"); return 0; }
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#Java
Java
import java.util.HashMap; import java.util.Map;   public class HofQ { private static Map<Integer, Integer> q = new HashMap<Integer, Integer>(){{ put(1, 1); put(2, 1); }};   private static int[] nUses = new int[100001];//not part of the task   public static int Q(int n){ nUses[n]++;//not part of the task if(...
http://rosettacode.org/wiki/Hello_world/Text
Hello world/Text
Hello world/Text is part of Short Circuit's Console Program Basics selection. Task Display the string Hello world! on a text console. Related tasks   Hello world/Graphical   Hello world/Line Printer   Hello world/Newbie   Hello world/Newline omission   Hello world/Standard error   Hello world/Web server
#Algae
Algae
printf("Hello world!\n");
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
ClearAll[Heron] Heron[a_, b_, c_] := With[{s = (a + b + c)/2}, Sqrt[s (s - a) (s - b) (s - c)]] PrintTemporary[Dynamic[{a, b, c}]]; results = Reap[ Do[ If[a < b + c \[And] b < c + a \[And] c < a + b, If[GCD[a, b, c] == 1, If[IntegerQ[Heron[a, b, c]], Sow[<|"Sides" -> {a, b, c}, "Area" -> H...
http://rosettacode.org/wiki/Heronian_triangles
Heronian triangles
Hero's formula for the area of a triangle given the length of its three sides   a,   b,   and   c   is given by: A = s ( s − a ) ( s − b ) ( s − c ) , {\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},} where   s   is half the perimeter of the triangle; that is, s = a + b + c 2 . {\displaystyle s...
#Nim
Nim
import math, algorithm, lenientops, strformat, sequtils   type HeronianTriangle = tuple[a, b, c: int; p: int; area: int]   func `$` (t: HeronianTriangle): string = fmt"{t.a:3d}, {t.b:3d}, {t.c:3d} {t.p:7d} {t.area:8d}"   func hero(a, b, c: int): float = let s = (a + b + c) / 2 result = sqrt(s * (s - a) * (s - b) ...
http://rosettacode.org/wiki/Higher-order_functions
Higher-order functions
Task Pass a function     as an argument     to another function. Related task   First-class functions
#Cowgol
Cowgol
include "cowgol.coh";   # In order to pass functions around, you must first define an interface. # This is similar to a delegate in C#; it becomes a function pointer type. # This interface takes two integers and returns one. interface Dyadic(x: int32, y: int32): (r: int32);   # For a function to be able to be passed ar...
http://rosettacode.org/wiki/Hello_world/Web_server
Hello world/Web server
The browser is the new GUI ! Task Serve our standard text   Goodbye, World!   to   http://localhost:8080/   so that it can be viewed with a web browser. The provided solution must start or implement a server that accepts multiple client connections and serves text as requested. Note that starting a web browser or...
#Phix
Phix
-- demo\rosetta\SimpleHttpServer.exw without js include builtins\sockets.e constant MAX_QUEUE = 100, ESCAPE = #1B, response = substitute(""" HTTP/1.1 200 OK Content-Type: text/html; charset=UTF-8 <!DOCTYPE html> <html> <head> <title>Bye-bye baby bye-bye</title> <style> body { ba...
http://rosettacode.org/wiki/Hofstadter_Figure-Figure_sequences
Hofstadter Figure-Figure sequences
These two sequences of positive integers are defined as: R ( 1 ) = 1   ;   S ( 1 ) = 2 R ( n ) = R ( n − 1 ) + S ( n − 1 ) , n > 1. {\displaystyle {\begin{aligned}R(1)&=1\ ;\ S(1)=2\\R(n)&=R(n-1)+S(n-1),\quad n>1.\end{aligned}}} The sequence S ( n ) {\displaystyle S(n)} is further...
#Sidef
Sidef
var r = [nil, 1] var s = [nil, 2]   func ffsr(n) { while(r.end < n) { r << s[r.end]+r[-1] s << [(s[-1]+1 .. r[-1]-1)..., r[-1]+1].grep{ s[-1] < _ }... } return n }   func ffr(n) { r[ffsr(n)] } func ffs(n) { s[ffsr(n)] }   printf(" i: R(i) S(i)\n") printf("==============\n") { |i| printf("%3d:  %3d  %...
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#Prolog
Prolog
horner([], _X, 0).   horner([H|T], X, V) :- horner(T, X, V1), V is V1 * X + H.  
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation
Horner's rule for polynomial evaluation
A fast scheme for evaluating a polynomial such as: − 19 + 7 x − 4 x 2 + 6 x 3 {\displaystyle -19+7x-4x^{2}+6x^{3}\,} when x = 3 {\displaystyle x=3\;} . is to arrange the computation as follows: ( ( ( ( 0 ) x + 6 ) x + ( − 4 ) ) x + 7 ) x + ( − 19 ) {\displaystyle ((((0)x+6)x+(-4))x...
#PureBasic
PureBasic
Procedure Horner(List Coefficients(), b) Define result ForEach Coefficients() result*b+Coefficients() Next ProcedureReturn result EndProcedure
http://rosettacode.org/wiki/Hilbert_curve
Hilbert curve
Task Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
#Wren
Wren
import "graphics" for Canvas, Color, Point import "dome" for Window   class Game { static init() { Window.title = "Hilbert curve" Canvas.resize(650, 650) Window.resize(650, 650) __points = [] __width = 64 hilbert(0, 0, __width, 0, 0) var col = Color.hex("#90EE...
http://rosettacode.org/wiki/Holidays_related_to_Easter
Holidays related to Easter
Task Calculate the dates of:   Easter   Ascension Thursday   Pentecost   Trinity Sunday   Corpus Christi feast (for Catholic)   All Saints' Sunday (for Orthodox) As an example, calculate for the first year of each century from;   years     400   to   2100 CE   and for   years   2010   to   2020 CE. Note ...
#PowerShell
PowerShell
  function Get-Easter { [CmdletBinding()] [OutputType([PSCustomObject])] Param ( [Parameter(Mandatory=$true, ValueFromPipeline=$true, ValueFromPipelineByPropertyName=$true, Position=0)] [int] $Year )   Begin { ...
http://rosettacode.org/wiki/Horizontal_sundial_calculations
Horizontal sundial calculations
Task Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location. For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit...
#REXX
REXX
/*REXX program displays: hour, sun hour angle, dial hour line angle, 6am ───► 6pm. */ numeric digits length( pi() ) - length(.) /*in case sundial is in polar regions. */ parse arg lat lng . /*obtain optional arguments from the CL*/ /* ┌─────────...
http://rosettacode.org/wiki/Huffman_coding
Huffman coding
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols. For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi...
#Rust
Rust
  use std::collections::BTreeMap; use std::collections::binary_heap::BinaryHeap;   #[derive(Debug, Eq, PartialEq)] enum NodeKind { Internal(Box<Node>, Box<Node>), Leaf(char), }   #[derive(Debug, Eq, PartialEq)] struct Node { frequency: usize, kind: NodeKind, }   impl Ord for Node { fn cmp(&self, rhs...
http://rosettacode.org/wiki/Identity_matrix
Identity matrix
Task Build an   identity matrix   of a size known at run-time. An identity matrix is a square matrix of size n × n, where the diagonal elements are all 1s (ones), and all the other elements are all 0s (zeroes). I n = [ 1 0 0 ⋯ 0 0 1 0 ⋯ 0 0 0 1 ⋯ 0 ⋮ ⋮ ⋮ ⋱ ...
#VBScript
VBScript
  build_matrix(7)   Sub build_matrix(n) Dim matrix() ReDim matrix(n-1,n-1) i = 0 'populate the matrix For row = 0 To n-1 For col = 0 To n-1 If col = i Then matrix(row,col) = 1 Else matrix(row,col) = 0 End If Next i = i + 1 Next 'display the matrix For row = 0 To n-1 For col = 0 To n-1 ...
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
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 |...
#V
V
[compare [ [>] ['less than' puts] [<] ['greater than' puts] [=] ['is equal' puts] ] when].   |2 3 compare greater than |3 2 compare less than |2 2 compare is equal
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
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 |...
#Vala
Vala
  void main(){ int a; int b;   stdout.printf("Please type in int 1\n"); a = int.parse(stdin.read_line());   stdout.printf("Please type in int 2\n"); b = int.parse(stdin.read_line());   if (a < b) stdout.printf("%d is less than %d\n", a, b); if (a == b) stdout.printf("%d i...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#M2000_Interpreter
M2000 Interpreter
  Module CheckIt { Declare xml "Microsoft.XMLHTTP" const testUrl$ = "http://www.rosettacode.org" With xml, "readyState" as ReadyState Method xml "Open", "Get", testUrl$, True ' True means Async Method xml "send" \\ We set a thread to count time k=0 Thread { ...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Maple
Maple
  content := URL:-Get( "http://www.google.com/" );  
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#Quackery
Quackery
[ $ "bigrat.qky" loadfile ] now!   [ ' [ 1 1 ] swap 2 - times [ dup -1 peek 2dup 1 - peek dip [ dip dup negate peek ] + join ] ] is hof-con ( n --> [ )   [ behead do rot witheach [ do 2over 2over v- v0< if 2swap 2drop ] ] ...
http://rosettacode.org/wiki/Hofstadter-Conway_$10,000_sequence
Hofstadter-Conway $10,000 sequence
The definition of the sequence is colloquially described as:   Starting with the list [1,1],   Take the last number in the list so far: 1, I'll call it x.   Count forward x places from the beginning of the list to find the first number to add (1)   Count backward x places from the end of the list to find the secon...
#R
R
f = local( {a = c(1, 1) function(n) {if (is.na(a[n])) a[n] <<- f(f(n - 1)) + f(n - f(n - 1)) a[n]}})
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#OCaml
OCaml
prerr_endline "Goodbye, World!"; (* this is how you print a string with newline to stderr *) Printf.eprintf "Goodbye, World!\n"; (* this is how you would use printf with stderr *)
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Octave
Octave
fprintf(stderr, "Goodbye, World!\n");
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Oforth
Oforth
System.Err "Goodbye, World!" << cr
http://rosettacode.org/wiki/Hello_world/Standard_error
Hello world/Standard error
Hello world/Standard error is part of Short Circuit's Console Program Basics selection. A common practice in computing is to send error messages to a different output stream than normal text console messages. The normal messages print to what is called "standard output" or "standard out". The error messages print to ...
#Ol
Ol
  (print-to stderr "Goodbye, World!")  
http://rosettacode.org/wiki/Hofstadter_Q_sequence
Hofstadter Q sequence
Hofstadter Q sequence Q ( 1 ) = Q ( 2 ) = 1 , Q ( n ) = Q ( n − Q ( n − 1 ) ) + Q ( n − Q ( n − 2 ) ) , n > 2. {\displaystyle {\begin{aligned}Q(1)&=Q(2)=1,\\Q(n)&=Q{\big (}n-Q(n-1){\big )}+Q{\big (}n-Q(n-2){\big )},\quad n>2.\end{aligned}}} It is defined like the Fibonacc...
#JavaScript
JavaScript
var hofstadterQ = function() { var memo = [1,1,1]; var Q = function (n) { var result = memo[n]; if (typeof result !== 'number') { result = Q(n - Q(n-1)) + Q(n - Q(n-2)); memo[n] = result; } return result; }; return Q; }();   for (var i = 1; i <=10; i += 1) { ...