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/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...
#Common_Lisp
Common Lisp
;;; equally doable with a list (flet ((seq (i) (make-array 1 :element-type 'integer :initial-element i :fill-pointer 1 :adjustable t))) (let ((rr (seq 1)) (ss (seq 2))) (labels ((extend-r () (let* ((l (1- (length rr))) (r (+ (aref rr l) (aref ss l))) (s (elt 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...
#Forth
Forth
: fhorner ( coeffs len F: x -- F: val ) 0e floats bounds ?do fover f* i f@ f+ 1 floats +loop fswap fdrop ;   create coeffs 6e f, -4e f, 7e f, -19e f,   coeffs 4 3e fhorner f. \ 128.
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...
#Fortran
Fortran
program test_horner   implicit none   write (*, '(f5.1)') horner ([-19.0, 7.0, -4.0, 6.0], 3.0)   contains   function horner (coeffs, x) result (res)   implicit none real, dimension (0:), intent (in) :: coeffs real, intent (in) :: x real :: res integer :: i   res = coeffs(ubound(coeffs,1))...
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.
#Factor
Factor
USING: accessors L-system ui ;   : hilbert ( L-system -- L-system ) L-parser-dialect >>commands [ 90 >>angle ] >>turtle-values "A" >>axiom { { "A" "-BF+AFA+FB-" } { "B" "+AF-BFB-FA+" } } >>rules ;   [ <L-system> hilbert "Hilbert curve" open-window ] with-ui
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.
#Forth
Forth
include lib/graphics.4th   64 constant /width \ hilbert curve order^2 9 constant /length \ length of a line   variable origin \ point of origin   aka r@ lg \ get parameters from return stack aka r'@ i1 ...
http://rosettacode.org/wiki/Honeycombs
Honeycombs
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position...
#Java
Java
import java.awt.*; import java.awt.event.*; import javax.swing.*;   public class Honeycombs extends JFrame {   public static void main(String[] args) { SwingUtilities.invokeLater(() -> { JFrame f = new Honeycombs(); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); f.setV...
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 ...
#Delphi
Delphi
  program Holidays_related_to_Easter;   {$APPTYPE CONSOLE}   uses System.SysUtils;   type THollyday = record name: string; offs: Integer; end;   const Holyday: array[0..4] of THollyday = (( name: 'Easter'; offs: 0 ), ( name: 'Ascension'; offs: 39 ), ( name: 'Pentecost'; offs:...
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...
#FutureBasic
FutureBasic
window 1   def fn rad2deg( theta as double ) as double = theta * 180 / pi def fn deg2rad( theta as double ) as double = theta * pi / 180   local fn SolarHourAngle( latitude as double, longitude as double, meridian as double ) long hour double hra, hla, t CFStringRef ap   print "Latitude = "; latitu...
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...
#Go
Go
package main   import ( "fmt" "math" "os" )   func getnum(prompt string) (r float64) { fmt.Print(prompt) if _, err := fmt.Scan(&r); err != nil { fmt.Println(err) os.Exit(-1) } return }   func main() { lat := getnum("Enter latitude => ") lng := getnum("Enter long...
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...
#Lua
Lua
local build_freqtable = function (data) local freq = { }   for i = 1, #data do local cur = string.sub (data, i, i) local count = freq [cur] or 0 freq [cur] = count + 1 end   local nodes = { } for w, f in next, freq do nodes [#nodes + 1] = { word = w, freq = f } end   table.sort (nodes, fun...
http://rosettacode.org/wiki/Host_introspection
Host introspection
Print the word size and endianness of the host machine. See also: Variable size/Get
#TI-89_BASIC
TI-89 BASIC
Disp "32-bit big-endian"
http://rosettacode.org/wiki/Host_introspection
Host introspection
Print the word size and endianness of the host machine. See also: Variable size/Get
#TXR
TXR
This is the TXR Lisp interactive listener of TXR 177. Use the :quit command or type Ctrl-D on empty line to exit. 1> (sizeof (ptr char)) 8 2> (sizeof int) 4
http://rosettacode.org/wiki/Host_introspection
Host introspection
Print the word size and endianness of the host machine. See also: Variable size/Get
#Wren
Wren
/* host_introspection.wren */   class C { foreign static wordSize foreign static endianness }   System.print("word size = %(C.wordSize) bits") System.print("endianness = %(C.endianness)")
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#PicoLisp
PicoLisp
(call 'hostname)
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Pike
Pike
import System;   int main(){ write(gethostname() + "\n"); }
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#PL.2FSQL
PL/SQL
SET serveroutput ON BEGIN DBMS_OUTPUT.PUT_LINE(UTL_INADDR.GET_HOST_NAME); END;
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 ⋮ ⋮ ⋮ ⋱ ...
#Prolog
Prolog
%rotates one list clockwise by one integer rotate(Int,List,Rotated) :- integer(Int), length(Suff,Int), append(Pre,Suff,List), append(Suff,Pre,Rotated). %rotates a list of lists by a list of integers rotate(LoInts,LoLists,Rotated) :- is_list(LoInts), maplist(rotate,LoInts,LoLists,Rotated).   %helper function appen...
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#Tcl
Tcl
set str 1234 incr str
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#TI-83_BASIC
TI-83 BASIC
:"1"→Str1 :expr(Str1)+1→A :{0,1}→L₁ :{0,A}→L₂ :LinReg(ax+b) Y₁ :Equ►String(Y₁,Str1) :sub(Str1,1,length(Str1)-3)→Str1
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 |...
#PowerShell
PowerShell
$a = [int] (Read-Host a) $b = [int] (Read-Host b)   if ($a -lt $b) { Write-Host $a is less than $b`. } elseif ($a -eq $b) { Write-Host $a is equal to $b`. } elseif ($a -gt $b) { Write-Host $a is greater than $b`. }
http://rosettacode.org/wiki/Integer_comparison
Integer comparison
Basic Data Operation This is a basic data operation. It represents a fundamental action on a basic data type. You may see other such operations in the Basic Data Operations category, or: Integer Operations Arithmetic | Comparison Boolean Operations Bitwise | Logical String Operations Concatenation | Interpolation |...
#PureBasic
PureBasic
If OpenConsole()   Print("Enter an integer: ") x.i = Val(Input()) Print("Enter another integer: ") y.i = Val(Input())   If x < y Print( "The first integer is less than the second integer.") ElseIf x = y Print("The first integer is equal to the second integer.") ElseIf x > y Print("The first ...
http://rosettacode.org/wiki/HTTP
HTTP
Task Access and print a URL's content (the located resource) to the console. There is a separate task for HTTPS Requests.
#Delphi
Delphi
  program HTTP;   {$APPTYPE CONSOLE}   {$DEFINE DEBUG}   uses Classes, httpsend; // Synapse httpsend class   var Response: TStrings; HTTPObj: THTTPSend;   begin HTTPObj := THTTPSend.Create; try { Stringlist object to capture HTML returned from URL } Response := TStringList.Create; try ...
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...
#EchoLisp
EchoLisp
  (decimals 4) (cache-size 2000000)   (define (a n) (+ (a (a (1- n))) (a (- n (a (1- n))))))   (remember 'a #(0 1 1)) ;; memoize   ;; prints max a(n)/n in [2**i 2**i+1] intervals ;; return Mallows number checked up to 2**20 (define (task (maxv) (start 1) (end 2) (v) (mrange 0)) (for ((i (in-range 1 21))) (set! 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 ...
#Agena
Agena
io.write( io.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 ...
#Aime
Aime
v_text("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 ...
#ALGOL_68
ALGOL 68
main:( put(stand error, ("Goodbye, World!", new line)) )
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...
#C.23
C#
using System; using System.Collections.Generic;   namespace HofstadterQSequence { class Program { // Initialize the dictionary with the first two indices filled. private static readonly Dictionary<int, int> QList = new Dictionary<int, int> ...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#Forth
Forth
[UNDEFINED] ANS [IF] include lib/fp1.4th \ Zen float version include lib/zenfprox.4th \ for F~ include lib/zenround.4th \ for FROUND include lib/zenfln.4th \ for FLN include lib/zenfpow.4th \ for FPOW [ELSE] include lib/fp3.4th ...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#Fortran
Fortran
program hickerson implicit none integer, parameter :: q = selected_real_kind(30) integer, parameter :: l = selected_int_kind(15) real(q) :: s, l2 integer :: i, n, k   l2 = log(2.0_q) do n = 1, 17 s = 0.5_q / l2 do i = 1, n s = (s * i) / l2 end do   ...
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...
#Ada
Ada
with Ada.Containers.Indefinite_Ordered_Sets; with Ada.Finalization; with Ada.Text_IO; use Ada.Text_IO; procedure Heronian is package Int_IO is new Ada.Text_IO.Integer_IO(Integer); use Int_IO;   -- ----- Some math... function GCD (A, B : in Natural) return Natural is (if B = 0 then A else GCD (B, A mod 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
#ActionScript
ActionScript
package { public class MyClass {   public function first(func:Function):String { return func.call(); }   public function second():String { return "second"; }   public static function main():void { var result:String = first(second); ...
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...
#AutoIt
AutoIt
  TCPStartup() $socket = TCPListen("0.0.0.0",8080) $string = "Goodbye, World!" While 1 Do $newConnection = TCPAccept($socket) Sleep(1) Until $newConnection <> -1 $content = TCPRecv($newConnection, 2048) If StringLen($content) > 0 Then TCPSend($newConnection, Binary("HTTP/1.1 200 OK" & @CRLF)) TC...
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 ...
#Arturo
Arturo
print {: The “Red Death” had long devastated the country. No pestilence had ever been so fatal, or so hideous.   Blood was its Avator and its seal— the redness and the horror of blood.   There were sharp pains, and sudden dizziness, and then profuse bleeding at the pores...
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 ...
#AutoHotkey
AutoHotkey
MyVar = "This is the text inside MyVar" MyVariable = ( Note that whitespace is preserved As well as newlines. The LTrim option can be present to remove left whitespace. Variable references such as %MyVar% are expanded. ) MsgBox % MyVariable
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 ...
#AWK
AWK
•Out "dsdfsdfsad ""fsadf""sdf"
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#Haskell
Haskell
import Data.IORef   newtype HVar a = HVar (IORef [a])   newHVar :: a -> IO (HVar a) newHVar value = fmap HVar (newIORef [value])   readHVar :: HVar a -> IO a readHVar (HVar ref) = fmap head (readIORef ref)   writeHVar :: a -> HVar a -> IO () writeHVar value (HVar ref) = modifyIORef ref (value:)   undoHVar :: HVar a -> ...
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#J
J
varref_hist_=:'VAR','_hist_',~] set_hist_=:4 :0 V=.varref x if.0>nc<V do.(<V)=:''end. (<V)=.V~,<y y ) getall_hist_=:3 :0 (varref y)~ ) length_hist_=: #@getall get_hist_=: _1 {:: getall
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...
#Cowgol
Cowgol
include "cowgol.coh"; include "strings.coh"; include "malloc.coh";   # An uint16 is big enough to deal with the figures from the task, # but it is good practice to allow it to be easily redefined. typedef N is uint16;   # There is no extensible vector type included in the standard library, # so it is necessary to defin...
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...
#D
D
int delegate(in int) nothrow ffr, ffs;   nothrow static this() { auto r = [0, 1], s = [0, 2];   ffr = (in int n) nothrow { while (r.length <= n) { immutable int nrk = r.length - 1; immutable int rNext = r[nrk] + s[nrk]; r ~= rNext; foreach (immutable sn; r...
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...
#FreeBASIC
FreeBASIC
  Function AlgoritmoHorner(coeffs() As Integer, x As Integer) As Integer Dim As Integer i, acumulador = 0 For i = Ubound(coeffs, 1) To 0 Step -1 acumulador = (acumulador * x) + coeffs(i) Next i Return acumulador End Function   Dim As Integer x = 3 Dim As Integer coeficientes(3) = {-19, 7, -4, 6...
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...
#FunL
FunL
import lists.foldr   def horner( poly, x ) = foldr( \a, b -> a + b*x, 0, poly )   println( horner([-19, 7, -4, 6], 3) )
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.
#FreeBASIC
FreeBASIC
  Dim Shared As Integer ancho = 64   Sub Hilbert(x As Integer, y As Integer, lg As Integer, i1 As Integer, i2 As Integer) If lg = 1 Then Line - ((ancho-x) * 10, (ancho-y) * 10) Return End If lg = lg / 2 Hilbert(x+i1*lg, y+i1*lg, lg, i1, 1-i2) Hilbert(x+i2*lg, y+(1-i2)*lg, lg, i1, i2)...
http://rosettacode.org/wiki/Honeycombs
Honeycombs
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position...
#Julia
Julia
using Gtk.ShortNames, GtkReactive, Graphics, Cairo, Colors, Random   mutable struct Hexagon center::Point radius::Int letter::String color::Colorant end   const offset = 50 const hgt = 450 const wid = 400 const hcombdim = (rows = 5, cols = 4) const randletters = reshape(string.(Char.(shuffle(UInt8('A'):...
http://rosettacode.org/wiki/Honeycombs
Honeycombs
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position...
#Kotlin
Kotlin
// version 1.1.4   import java.awt.BasicStroke import java.awt.BorderLayout import java.awt.Color import java.awt.Dimension import java.awt.Font import java.awt.Graphics import java.awt.Graphics2D import java.awt.Polygon import java.awt.RenderingHints import java.awt.event.KeyAdapter import java.awt.event.KeyEvent impo...
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 ...
#Elixir
Elixir
defmodule Holiday do @offsets [ Easter: 0, Ascension: 39, Pentecost: 49, Trinity: 56, Corpus: 60 ] @mon { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" }   def easter_date(year) do a = rem(year, 19) b = div(year, 100) c = rem(year, 100) d = div(b, 4) 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...
#GW-BASIC
GW-BASIC
10 ' Horizontal sundial calculations 20 PRINT "Enter latitude => "; 30 INPUT LAT 40 PRINT "Enter longitude => "; 50 INPUT LNG 60 PRINT "Enter legal meridian => "; 70 INPUT REF 80 PRINT 90 LET PI = 4 * ATN(1) 100 LET SLAT = SIN(LAT * PI / 180) 110 PRINT " sine of latitude: "; USING "#.##^^^^"; ...
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...
#M2000_Interpreter
M2000 Interpreter
  Module Huffman { comp=lambda (a, b) ->{ =array(a, 0)<array(b, 0) } module InsertPQ (a, n, &comp) { if len(a)=0 then stack a {data n} : exit if comp(n, stackitem(a)) then stack a {push n} : exit stack a { push n t=2:...
http://rosettacode.org/wiki/Host_introspection
Host introspection
Print the word size and endianness of the host machine. See also: Variable size/Get
#XPL0
XPL0
include c:\cxpl\codes; \intrinsic 'code' declarations int A, B; char C; [IntOut(0, @B-@A); CrLf(0); \word size = integer size A:= $1234; C:= @A; Text(0, if C(0)=$34 then "Little" else "Big"); Text(0, " endian "); ]
http://rosettacode.org/wiki/Host_introspection
Host introspection
Print the word size and endianness of the host machine. See also: Variable size/Get
#Z80_Assembly
Z80 Assembly
EndianTest: ld hl,&8000 ld (&C000),hl ;store &8000 into memory. ld a,(&C000) ;loads the byte at &C000 into A. If the Z80 were big-endian, A would equal &80. But it equals zero. or a ;still, we need to pretend we don't already know the result and compare A to zero. jr z,LittleEndian ;handle the cas...
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Pop11
Pop11
lvars host = sys_host_name();
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#PowerBASIC
PowerBASIC
HOST NAME TO hostname$
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#PowerShell
PowerShell
$Env:COMPUTERNAME
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#PureBasic
PureBasic
InitNetwork() answer$=Hostname()
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 ⋮ ⋮ ⋮ ⋱ ...
#PureBasic
PureBasic
>Procedure identityMatrix(Array i(2), size) ;valid only for size >= 0 ;formats array i() as an identity matrix of size x size Dim i(size - 1, size - 1)   Protected j For j = 0 To size - 1 i(j, j) = 1 Next EndProcedure     Procedure displayMatrix(Array a(2)) Protected rows = ArraySize(a(), 2), columns =...
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#TI-89_BASIC
TI-89 BASIC
string(expr(str)+1)
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#Toka
Toka
" 100" >number drop 1 + >string
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 |...
#Python
Python
#!/usr/bin/env python a = input('Enter value of a: ') b = input('Enter value of b: ')   if a < b: print 'a is less than b' elif a > b: print 'a is greater than b' elif a == b: print 'a is equal to b'
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 |...
#Quackery
Quackery
$ "Please enter two numbers separated by a space; " input quackery cr say "The first number is " [ 2dup > iff [ say "larger than" ] done 2dup = iff [ say "equal to" ] done 2dup < if [ say "smaller than" ] ] 2drop say " the second number." cr
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.
#Dragon
Dragon
select "http" select "std"   http("http://www.rosettacode.org", ::echo)    
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.
#E
E
  when (def t := <http://www.rosettacode.org> <- getText()) -> { println(t) }  
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...
#Eiffel
Eiffel
  class APPLICATION   create make   feature   make --Tests the feature sequence. local j, n, exp: INTEGER max: REAL_64 do exp := 15 n := (2 ^ exp).floor sequence (n) across 1 |..| (exp - 1) as c loop max := 0 from j := (2 ^ c.item).floor until j > 2 ^ (c.item + 1...
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 ...
#Argile
Argile
use std eprint "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 ...
#ARM_Assembly
ARM Assembly
  /* ARM assembly Raspberry PI */ /* program hellowordLP.s */ .data szMessage: .asciz "Goodbye world. \n " @ error message .equ LGMESSAGE, . - szMessage @ compute length of message   .text .global main main: mov r0, #2 @ output error linux ldr r1, iAdrMessage @ adresse of ...
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...
#C.2B.2B
C++
#include <iostream>   int main() { const int size = 100000; int hofstadters[size] = { 1, 1 }; for (int i = 3 ; i < size; i++) hofstadters[ i - 1 ] = hofstadters[ i - 1 - hofstadters[ i - 1 - 1 ]] + hofstadters[ i - 1 - hofstadters[ i - 2 - 1 ]]; std::cout << "The first ...
http://rosettacode.org/wiki/Hickerson_series_of_almost_integers
Hickerson series of almost integers
The following function,   due to D. Hickerson,   is said to generate "Almost integers" by the "Almost Integer" page of Wolfram MathWorld,   (December 31 2013).   (See formula numbered   51.) The function is:           h ( n ) = n ! 2 ( ln ⁡ 2 ) n + 1 {\displaystyle h(n)={\operatorname {n} ! \ove...
#FreeBASIC
FreeBASIC
' version 08-10-2016 ' compile with: fbc -s gui   #Include Once "gmp.bi"   #Macro init_float_size (big_float ,size) Dim As Mpf_ptr big_float = Allocate( Len( __mpf_struct)) Mpf_init2( big_float,size) #EndMacro   #Macro mpf_remove(big_float) Mpf_clear(big_float) DeAllocate (big_float) #EndMacro   Screen 20   ini...
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...
#ALGOL_68
ALGOL 68
# mode to hold details of a Heronian triangle # MODE HERONIAN = STRUCT( INT a, b, c, area, perimeter ); # returns the details of the Heronian Triangle with sides a, b, c or nil if it isn't one # PROC try ht = ( INT a, b, c )REF HERONIAN: BEGIN REF HERONIAN t := NIL; REAL s = ( a + 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
#Ada
Ada
with Ada.Text_Io; use Ada.Text_Io;   procedure Subprogram_As_Argument is type Proc_Access is access procedure;   procedure Second is begin Put_Line("Second Procedure"); end Second;   procedure First(Proc : Proc_Access) is begin Proc.all; end First; begin First(Second'Access); end Sub...
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...
#AWK
AWK
#!/usr/bin/gawk -f BEGIN { RS = ORS = "\r\n" HttpService = "/inet/tcp/8080/0/0" Hello = "<HTML><HEAD>" \ "<TITLE>A Famous Greeting</TITLE></HEAD>" \ "<BODY><H1>Hello, world</H1></BODY></HTML>" Len = length(Hello) + length(ORS) print "HTTP/1.0 200 OK"...
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...
#BaCon
BaCon
' Define HTTP constants CONST New$ = CHR$(13) & NL$ CONST Sep$ = CHR$(13) & NL$ & CHR$(13) & NL$ CONST Msg$ = "<html><head>BaCon web greeting</head><body><h2>Goodbye, World!</h2></body></html>"   ' Get our IP Ip$ = "localhost" PRINT "Connect from browser '", Ip$, ":8080'."   ' Ignore child signals to avoid zombie proce...
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#BQN
BQN
•Out "dsdfsdfsad ""fsadf""sdf"
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#Bracmat
Bracmat
( {Multiline string:} " Second line Third line \"quoted\" A backslash: \\ ":?stringA & out$("Multiline string:") & out$(!stringA) )
http://rosettacode.org/wiki/Here_document
Here document
A   here document   (or "heredoc")   is a way of specifying a text block, preserving the line breaks, indentation and other whitespace within the text. Depending on the language being used, a   here document   is constructed using a command followed by "<<" (or some other symbol) followed by a token string. The text ...
#BaCon
BaCon
  '--- we dont have a print here doc built-in command in BaCon '--- we can get the end result like this with the newline NL$   PRINT "To use Bacon your system must have either Korn Shell, or ZShell, or Bourne Again Shell (BASH) available." NL$ \ "If none of these shells are available on your platform, download and i...
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 ...
#BASIC
BASIC
  text1$ = " " + CHR$(10) + "<<'FOO' " + CHR$(10) + " 'jaja', `esto`" + CHR$(10) + " <simula>" + CHR$(10) + " \un\" + CHR$(10) + " ${ejemplo} de 'heredoc'" + CHR$(10) + " en QBASIC."   text2$ = "Esta es la primera línea." + CHR$(10) + "Esta es la segunda línea." + CHR$(10) + "Esta 'línea' contiene comillas."   PRI...
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#Java
Java
import java.util.Collections; import java.util.LinkedList; import java.util.List;   /** * A class for an "Integer with a history". * <p> * Note that it is not possible to create an empty Variable (so there is no "null") with this type. This is a design * choice, because if "empty" variables were allowed, reading of...
http://rosettacode.org/wiki/History_variables
History variables
Storing the history of objects in a program is a common task. Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging. History variables are variables in a programming la...
#Julia
Julia
mutable struct Historied num::Number history::Vector{Number} Historied(n) = new(n, Vector{Number}()) end   assign(y::Historied, z) = (push!(y.history, y.num); y.num = z; y)   x = Historied(1)   assign(x, 3) assign(x, 5) assign(x, 4)   println("Past history of variable x: $(x.history). Current value is $(x.n...
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...
#EchoLisp
EchoLisp
(define (FFR n) (+ (FFR (1- n)) (FFS (1- n))))   (define (FFS n) (define next (1+ (FFS (1- n)))) (for ((k (in-naturals next))) #:break (not (vector-search* k (cache 'FFR))) => k ))   (remember 'FFR #(0 1)) ;; init cache (remember 'FFS #(0 2))  
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...
#Euler_Math_Toolbox
Euler Math Toolbox
  >function RSstep (r,s) ... $ n=cols(r); $ r=r|(r[n]+s[n]); $ s=s|(max(s[n]+1,r[n]+1):r[n+1]-1); $ return {r,s}; $ endfunction >function RS (n) ... $ if n==1 then return {[1],[2]}; endif; $ if n==2 then return {[1,3],[2]}; endif; $ r=[1,3]; s=[2,4]; $ loop 3 to n; {r,s}=RSstep(r,s); end; $ return {r,s}; $ e...
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...
#FutureBasic
FutureBasic
include "NSLog.incl"   local fn horner( coeffs as CFArrayRef, x as NSInteger ) as double CFArrayRef reversedCoeffs CFNumberRef num double accumulator = 0.0   // Reverse coeffs array reversedCoeffs = fn EnumeratorAllObjects( fn ArrayReverseObjectEnumerator( coeffs ) )   // Iterate over CFNumberRefs in reversed arr...
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...
#GAP
GAP
# The idiomatic way to compute with polynomials   x := Indeterminate(Rationals, "x");   # This is a value in a polynomial ring, not a function p := 6*x^3 - 4*x^2 + 7*x - 19;   Value(p, 3); # 128   u := CoefficientsOfUnivariatePolynomial(p); # [ -19, 7, -4, 6 ]   # One may also create the polynomial from coefficients q ...
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.
#F.C5.8Drmul.C3.A6
Fōrmulæ
// General description: // This code creates Lindenmayer rules via string manipulation // It can generate many of the examples from the Wikipedia page // discussing L-system fractals: http://en.wikipedia.org/wiki/L-system // // It does not support stochastic, context sensitive or parametric grammars // // It supports f...
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.
#Frink
Frink
// General description: // This code creates Lindenmayer rules via string manipulation // It can generate many of the examples from the Wikipedia page // discussing L-system fractals: http://en.wikipedia.org/wiki/L-system // // It does not support stochastic, context sensitive or parametric grammars // // It supports f...
http://rosettacode.org/wiki/Honeycombs
Honeycombs
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position...
#Liberty_BASIC
Liberty BASIC
  NoMainWin Dim hxc(20,2), ltr(26) Global sw, sh, radius, radChk, mx, my, h$, last h$="#g": radius = 40: radChk = 35 * 35: last = 0 sw = 400: sh = 380: WindowWidth = sw+6: WindowHeight= sh+32 Open "Liberty BASIC - Honeycombs" For graphics_nsb_nf As #g #g "Down; Cls; TrapClose xit"   Call shuffle Call grid 75, 15, "0 0 ...
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 ...
#Erlang
Erlang
-module(holidays). -export([task/0]).   offsets(easter) -> 0; offsets(ascension) -> 39; offsets(pentecost) -> 49; offsets(trinity) -> 56; offsets(corpus) -> 60.   month(Month) -> element(Month, { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" } ).   easter_date(Year) -> ...
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...
#Haskell
Haskell
roundDec :: Int -> Double -> Double roundDec d = (/ 10.0 ^ d) . fromIntegral . round . (* 10.0 ^ d)   radToDegr = ((180 / pi) *)   degrToRad = ((pi / 180) *)   main = do let lat = -4.95 long = -150.5 legalMerid = -150 sinOfLat = sin $ degrToRad lat diff = legalMerid - long (putStrLn . unline...
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...
#Mathematica_.2F_Wolfram_Language
Mathematica / Wolfram Language
huffman[s_String] := huffman[Characters[s]]; huffman[l_List] := Module[{merge, structure, rules},   (*merge front two branches. list is assumed to be sorted*) merge[k_] := Replace[k, {{a_, aC_}, {b_, bC_}, rest___} :> {{{a, b}, aC + bC}, rest}];   structure = FixedPoint[ Composition[merge, SortBy[#, Last...
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Python
Python
import socket host = socket.gethostname()
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#R
R
Sys.info()[["nodename"]]
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Racket
Racket
  #lang racket/base (require racket/os) (gethostname)  
http://rosettacode.org/wiki/Hostname
Hostname
Task Find the name of the host on which the routine is running.
#Raku
Raku
my $host = qx[hostname];
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 ⋮ ⋮ ⋮ ⋱ ...
#Python
Python
def identity(size): matrix = [[0]*size for i in range(size)] #matrix = [[0] * size] * size #Has a flaw. See http://stackoverflow.com/questions/240178/unexpected-feature-in-a-python-list-of-lists   for i in range(size): matrix[i][i] = 1   for rows in matrix: for elements in rows: ...
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#TorqueScript
TorqueScript
$string = "12345"; $string++;
http://rosettacode.org/wiki/Increment_a_numerical_string
Increment a numerical string
Task Increment a numerical string.
#TUSCRIPT
TUSCRIPT
  $$ MODE TUSCRIPT teststring="0'1'-1'12345'10000000'-10000000" LOOP/CLEAR n=teststring n=n+1 PRINT n ENDLOOP  
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 |...
#R
R
print("insert number a") a <- scan(what=numeric(0), nmax=1) print("insert number b") b <- scan(what=numeric(0), nmax=1) if ( a < b ) { print("a is less than b") } else if ( a > b ) { print("a is greater than b") } else if ( a == b ) { # could be simply else of course... print("a and b are the same") }
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 |...
#Racket
Racket
#lang racket (define (compare-two-ints a b) (define compared (cond ((> a b) "is greated than") ((= a b) "equals") ((< a b) "is lesser than"))) (format "~a ~a ~a" a compared b))   (compare-two-ints (read) (read))
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.
#EchoLisp
EchoLisp
  ;; asynchronous call back definition (define (success name text) (writeln 'Loaded name) (writeln text)) ;; (file->string success "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...
#Erlang
Erlang
  -module( hofstadter_conway ).   -export( [sequence/1, sequence_div_n/1, task/0] ).   -record( power_of_2, {div_n=0, max=4, min=2, n=0} ).   sequence( 1 ) -> [1]; sequence( 2 ) -> [1, 1]; sequence( Up_to ) when Up_to >= 3 -> From_3 = lists:seq( 3, Up_to ), Dict = lists:foldl( fun sequence_dict/2, dict:...
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 ...
#Arturo
Arturo
panic "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 ...
#ATS
ATS
implement main0 () = fprint (stderr_ref, "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 ...
#AutoHotkey
AutoHotkey
; c:\> autohotkey.exe stderr.ahk 2> error.txt FileAppend, Goodbye`, World!, stderr ; requires AutoHotkey_N
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...
#Clojure
Clojure
(defn qs [q] (let [n (count q)] (condp = n 0 [1] 1 [1 1] (conj q (+ (q (- n (q (- n 1)))) (q (- n (q (- n 2)))))))))   (defn qfirst [n] (-> (iterate qs []) (nth n)))   (println "first 10:" (qfirst 10)) (println "1000th:" (last (qfirst 1000))) (println "extra credit:" (->> (qfirs...