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 | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
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... | #Rust | Rust | fn horner(v: &[f64], x: f64) -> f64 {
v.iter().rev().fold(0.0, |acc, coeff| acc*x + coeff)
}
fn main() {
let v = [-19., 7., -4., 6.];
println!("result: {}", horner(&v, 3.0));
} | Give a code snippet in #Rust
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
)
{\d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_stability | Sort stability |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #TXR | TXR | import "/sort" for Cmp, Sort
var data = [ ["UK", "London"], ["US", "New York"], ["US", "Birmingham"], ["UK", "Birmingham"] ]
// for sorting by country
var cmp = Fn.new { |p1, p2| Cmp.string.call(p1[0], p2[0]) }
// for sorting by city
var cmp2 = Fn.new { |p1, p2| Cmp.string.call(p1[1], p2[1]) }
System.print("Ini... | Give a code snippet in #TXR
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loop_over_multiple_arrays_simultaneously | Loop over multiple arrays simultaneously | Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this example, loop over the arrays:
... | #Babel | Babel | main: { (('a' 'b' 'c')('A' 'B' 'C')('1' '2' '3'))
simul_array }
simul_array!:
{ trans
{ { << } each "\n" << } each } | Give a code snippet in #Babel
Task
Loop over multiple arrays (or lists or tuples or whatever they're called in
your language) and display the i th element of each.
Use your language's "for each" loop if it has one, otherwise iterate
through the collection in order with some other loop.
For this exam... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another pr... | #Swift | Swift | import Foundation
let fmtDbl = { String(format: "%10.3f", $0) }
Task.detached {
let formatter = DateFormatter()
formatter.dateFormat = "yyyy-MM-dd"
let (data, _) = try await URLSession.shared.bytes(from: URL(fileURLWithPath: CommandLine.arguments[1]))
var rowStats = [(Date, Double, Int)]()
var invalid... | Give a code snippet in #Swift
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #LLVM | LLVM | ; This is not strictly LLVM, as it uses the C library function "printf".
; LLVM does not provide a way to print values, so the alternative would be
; to just load the string into memory, and that would be boring.
; Additional comments have been inserted, as well as changes made from the output produced by clang such ... | Give a code snippet in #LLVM
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_and_permutations | Combinations and permutations |
This page uses content from Wikipedia. The original article was at Combination. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
This page uses content from Wikipedia. The original article was at P... | #Tcl | Tcl | # Exact integer versions
proc tcl::mathfunc::P {n k} {
set t 1
for {set i $n} {$i > $n-$k} {incr i -1} {
set t [expr {$t * $i}]
}
return $t
}
proc tcl::mathfunc::C {n k} {
set t [P $n $k]
for {set i $k} {$i > 1} {incr i -1} {
set t [expr {$t / $i}]
}
return $t
}
# Floating point vers... | Give a code snippet in #Tcl
This page uses content from Wikipedia. The original article was at Combination. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
This page uses content from Wikipedia. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compiler/code_generator | Compiler/code generator | A code generator translates the output of the syntax analyzer and/or semantic analyzer
into lower level code, either assembly, object, or virtual.
Task[edit]
Take the output of the Syntax analyzer task - which is a flattened Abstract Syntax Tree (AST) - and convert it to virtual machine code, that can be run by the
Vi... | #Scala | Scala |
package xyz.hyperreal.rosettacodeCompiler
import scala.collection.mutable.{ArrayBuffer, HashMap}
import scala.io.Source
object CodeGenerator {
def fromStdin = fromSource(Source.stdin)
def fromString(src: String) = fromSource(Source.fromString(src))
def fromSource(ast: Source) = {
val vars ... | Give a code snippet in #Scala
A code generator translates the output of the syntax analyzer and/or semantic analyzer
into lower level code, either assembly, object, or virtual.
Task[edit]
Take the output of the Syntax analyzer task - which is a flattened Abstract Syntax Tree (AST) - and convert it to virtual machine ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_triangle | Sierpinski triangle | Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
* * * *
... | #CLU | CLU | sierpinski = proc (size: int) returns (string)
ss: stream := stream$create_output()
for i: int in int$from_to(0, size*4-1) do
c: int := 1
for j: int in int$from_to(1, size*4-1-i) do
stream$putc(ss, ' ')
end
for k: int in int$from_to(0, i) do
if c//2=0 th... | Give a code snippet in #CLU
Task
Produce an ASCII representation of a Sierpinski triangle of order N.
Example
The Sierpinski triangle of order 4 should look like this:
*
* *
* *
* * * *
* *
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reflection/Get_source | Reflection/Get source | Task
The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
| #Kotlin | Kotlin | // Kotlin JS Version 1.2.31
fun hello() {
println("Hello")
}
fun main(args: Array<String>) {
val code = js("_.hello.toString()")
println(code)
}
| Give a code snippet in #Kotlin
Task
The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #Yabasic | Yabasic | i = 1024
while i > 0
Print i
i = int(i / 2)
wend
end | Give a code snippet in #Yabasic
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downw... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list | Search a list | Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that has multiple occurrences in ... | #Aime | Aime | void
search(list l, text s)
{
integer i;
i = 0;
while (i < ~l) {
if (l[i] == s) {
break;
}
i += 1;
}
o_(s, " is ", i == ~l ? "not in the haystack" : "at " + itoa(i), "\n");
}
integer
main(void)
{
list l;
l = l_effect("Zig", "Zag", "Wally", "Ronald"... | Give a code snippet in #Aime
Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle tha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #PARI.2FGP | PARI/GP | BLOCKS = "BOXKDQCPNAGTRETGQDFSJWHUVIANOBERFSLYPCZM";
WORDS = ["A","Bark","BOOK","Treat","COMMON","SQUAD","conFUSE"];
can_make_word(w) = check(Vecsmall(BLOCKS), Vecsmall(w))
check(B,W,l=1,n=1) =
{
if (l > #W, return(1), n > #B, return(0));
forstep (i = 1, #B-2, 2,
if (B[i] != bitand(W[l],223) && B[i+1] !=... | Give a code snippet in #PARI.2FGP
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
begin
while TRUE do
writeln("SPAM");
end while;
end func; | Give a code snippet in #Seed7
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Classes | Classes | In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the class.
A class of types itself, a... | #MATLAB | MATLAB | function GenericClassInstance = GenericClass(varargin)
if isempty(varargin) %No input arguments
GenericClassInstance.classVariable = 0; %Generates a struct
else
GenericClassInstance.classVariable = varargin{1}; %Generates a struct
end
%Converts th... | Give a code snippet in #MATLAB
In object-oriented programming class is a set (a transitive closure) of types bound by the relation of inheritance. It is said that all types derived from some base type T and the type T itself form a class T.
The first type T from the class T sometimes is called the root type of the cl... | christopher/rosetta-code | |
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. | Give a code snippet in #Metafont
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 o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Named_parameters | Named parameters | Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this.
Note:
Named parameters relies on being able to use the names give... | #Kotlin | Kotlin | // version 1.0.6
fun someFunction(first: String, second: Int = 2, third: Double) {
println("First = ${first.padEnd(10)}, Second = $second, Third = $third")
}
fun main(args: Array<String>) {
// using positional parameters
someFunction("positional", 1, 2.0)
// using named parameters
someFunction... | Give a code snippet in #Kotlin
Create a function which takes in a number of arguments which are specified by name rather than (necessarily) position, and show how to call the function. If the language supports reordering the arguments or optionally omitting some of them, note this.
Note:
Named parameters relies on ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, ... | #Microsoft_Small_Basic | Microsoft Small Basic | TextWindow.WriteLine(Math.Power(0,0)) | Give a code snippet in #Microsoft_Small_Basic
Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Letter_frequency | Letter frequency | Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequen... | #Prolog | Prolog | frequency(File) :-
read_file_to_codes(File, Code, []),
% we only keep alphabetic codes
include(my_code_type, Code, LstCharCode),
% we translate char_codes into uppercase atoms.
maplist(my_upcase, LstCharCode, LstChar),
% sort and pack the list
msort(LstChar, SortLstChar),
packList(SortLstChar, Freq),
map... | Give a code snippet in #Prolog
Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #Tailspin | Tailspin |
// arrays are created as literals, by simply listing elements, or by a generator expression, or a combination.
def a: [1, 2, 3..7:2, 11];
$a -> !OUT::write
'
' -> !OUT::write
// Natural indexes start at 1
$a(1) -> !OUT::write
'
' -> !OUT::write
// You can select a range
$a(3..last) -> !OUT::write
'
' -> !OUT::wri... | Give a code snippet in #Tailspin
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almkvist-Giullera_formula_for_pi | Almkvist-Giullera formula for pi | The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10002n+1
This formula can be used to calcul... | #PicoLisp | PicoLisp | (scl 70)
(de fact (N)
(if (=0 N)
1
(* N (fact (dec N))) ) )
(de almkvist (N)
(let
(A (* 32 (fact (* 6 N)))
B (+ (* 532 N N) (* 126 N) 9)
C (* (** (fact N) 6) 3) )
(/ (* A B) C) ) )
(de integral (N)
(*/
1.0
(almkvist N)
(** 10 (+ 3 (* 6 N))) ) )
(let (... | Give a code snippet in #PicoLisp
The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10002n+1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primorial_numbers | Primorial numbers | Primorial numbers are those formed by multiplying successive prime numbers.
The primorial number series is:
primorial(0) = 1 (by definition)
primorial(1) = 2 (2)
primorial(2) = 6 (2×3)
primorial(3) = 30 (2×3×5)
primorial(4) = 210 (2×3×5×... | #Clojure | Clojure | (ns example
(:gen-class))
; Generate Prime Numbers (Implementation from RosettaCode--link above)
(defn primes-hashmap
"Infinite sequence of primes using an incremental Sieve or Eratosthenes with a Hashmap"
[]
(letfn [(nxtoddprm [c q bsprms cmpsts]
(if (>= c q) ;; only ever equal
; Up... | Give a code snippet in #Clojure
Primorial numbers are those formed by multiplying successive prime numbers.
The primorial number series is:
primorial(0) = 1 (by definition)
primorial(1) = 2 (2)
primorial(2) = 6 (2×3)
primorial(3) = 30 (2×3×5)
pri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_input/Obtain_a_Y_or_N_response | Keyboard input/Obtain a Y or N response |
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed, and there should be no need t... | #Rust | Rust | //cargo-deps: ncurses
extern crate ncurses;
use ncurses::*;
fn main() {
initscr();
loop {
printw("Yes or no? ");
refresh();
match getch() as u8 as char {
'Y'|'y' => {printw("You said yes!");},
'N'|'n' => {printw("You said no!");},
_ => {printw("T... | Give a code snippet in #Rust
Task
Obtain a valid Y or N response from the keyboard.
The keyboard should be flushed, so that any outstanding key-presses are removed, preventing any existing Y or N key-press from being evaluated.
The response should be obtained as soon as Y or N are pressed,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Deconvolution/1D | Deconvolution/1D | The convolution of two functions
F
{\displaystyle {\mathit {F}}}
and
H
{\displaystyle {\mathit {H}}}
of
an integer variable is defined as the function
G
{\displaystyle {\mathit {G}}}
satisfying
G
(
n
)
=
∑
m
=
−
∞
∞
F
(
m
)
H
(
n
−
m
)
{\displaystyle G(n)=\sum _{m=-\inft... | #R | R | conv <- function(a, b) {
p <- length(a)
q <- length(b)
n <- p + q - 1
r <- nextn(n, f=2)
y <- fft(fft(c(a, rep(0, r-p))) * fft(c(b, rep(0, r-q))), inverse=TRUE)/r
y[1:n]
}
deconv <- function(a, b) {
p <- length(a)
q <- length(b)
n <- p - q + 1
r <- nextn(max(p, q), f=2)
y <- fft(fft(c(a, rep(0, r-p))) / ff... | Give a code snippet in #R
The convolution of two functions
F
{\displaystyle {\mathit {F}}}
and
H
{\displaystyle {\mathit {H}}}
of
an integer variable is defined as the function
G
{\displaystyle {\mathit {G}}}
satisfying
G
(
n
)
=
∑
m
=
−
∞
∞
F
(
m
)
H
(
n
−
m
)
{\displa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Simple_moving_average | Averages/Simple moving average | Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a method for computing an avera... | #BQN | BQN | SMA ← {(+´÷≠)¨(1↓𝕨↑↑𝕩)∾<˘𝕨↕𝕩}
v ← (⊢∾⌽)1+↕5
•Show 5 SMA v
SMA2 ← {
𝕊 size:
nums ← ⟨⟩
sum ← 0
{
nums ∾↩ 𝕩
gb ← {(≠nums)≤size ? 0 ; a←⊑nums, nums↩1↓nums, a}
sum +↩ 𝕩 - gb
sum ÷ ≠nums
}
}
fun ← SMA2 5
Fun¨ v | Give a code snippet in #BQN
Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_interpolation_(included) | String interpolation (included) |
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 |... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
local
const string: original is "Mary had a X lamb";
const string: little is "little";
var string: replaced is "";
begin
replaced := replace(original, "X", little);
writeln(replaced);
end func; | Give a code snippet in #Seed7
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Grayscale_image | Grayscale image | Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To get luminance of a color u... | #MATLAB | MATLAB | function [grayImage] = colortograyscale(inputImage)
grayImage = rgb2gray(inputImage); | Give a code snippet in #MATLAB
Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #Nim | Nim | import std / strutils
func canMakeWord(blocks: seq[string]; word: string): bool =
if blocks.len < word.len: return false
if word.len == 0: return true
let ch = word[0].toUpperAscii
for i, pair in blocks:
if ch in pair and
(blocks[0..<i] & blocks[i+1..^1]).canMakeWord(word[1..^1]):... | Give a code snippet in #Nim
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For | Loops/For | “For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers.
... | #Racket | Racket | (for ([i (in-range 1 6)]) (for ([j i]) (display "*")) (newline)) | Give a code snippet in #Racket
“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract struct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #ALGOL_W | ALGOL W | begin
% String literals are enclosed in double-quotes in Algol W. %
% There isn't a separate character type but strings of lenghth one can %
% be used instead. %
% There are no escaping conventions used in string literals, except that ... | Give a code snippet in #ALGOL_W
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Increment_a_numerical_string | Increment a numerical string | Task
Increment a numerical string.
| #Ring | Ring |
x = "1234" See 1+x # print 1235
| Give a code snippet in #Ring
Task
Increment a numerical string.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bell_numbers | Bell numbers | Bell or exponential numbers are enumerations of the number of different ways to partition a set that has exactly n elements. Each element of the sequence Bn is the number of partitions of a set of size n where order of the elements and order of the partitions are non-significant. E.G.: {a b} is the same as {b a} and {a... | #Factor | Factor | USING: formatting io kernel math math.matrices sequences vectors ;
: next-row ( prev -- next )
[ 1 1vector ]
[ dup last [ + ] accumulate swap suffix! ] if-empty ;
: aitken ( n -- seq )
V{ } clone swap [ next-row dup ] replicate nip ;
0 50 aitken col [ 15 head ] [ last ] bi
"First 15 Bell numbers:\n%[%... | Give a code snippet in #Factor
Bell or exponential numbers are enumerations of the number of different ways to partition a set that has exactly n elements. Each element of the sequence Bn is the number of partitions of a set of size n where order of the elements and order of the partitions are non-significant. E.G.: {... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government... | #Arturo | Arturo | print digest.sha "The quick brown fox jumped over the lazy dog's back" | Give a code snippet in #Arturo
SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to id... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations/Derangements | Permutations/Derangements | A derangement is a permutation of the order of distinct items in which no item appears in its original place.
For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1).
The number of derangements of n distinct items is known as the subfactorial of n, sometimes written as !n.
The... | #Wren | Wren | import "/fmt" for Fmt
import "/big" for BigInt
var permute // recursive
permute = Fn.new { |input|
if (input.count == 1) return [input]
var perms = []
var toInsert = input[0]
for (perm in permute.call(input[1..-1])) {
for (i in 0..perm.count) {
var newPerm = perm.toList
... | Give a code snippet in #Wren
A derangement is a permutation of the order of distinct items in which no item appears in its original place.
For example, the only two derangements of the three items (0, 1, 2) are (1, 2, 0), and (2, 0, 1).
The number of derangements of n distinct items is known as the subfactorial of n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leonardo_numbers | Leonardo numbers |
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) = L(n-1) + L(n-2) + 1 ... | #Racket | Racket | #lang racket
(define (Leonardo n #:L0 (L0 1) #:L1 (L1 1) #:1+ (1+ 1))
(cond [(= n 0) L0]
[(= n 1) L1]
[else
(let inr ((n (- n 2)) (L_n-2 L0) (L_n-1 L1))
(let ((L_n (+ L_n-1 L_n-2 1+)))
(if (zero? n) L_n (inr (sub1 n) L_n-1 L_n))))]))
(module+ main
(map Leonardo (ra... | Give a code snippet in #Racket
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Five_weekends | Five weekends | The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property (there should be 201).
Show at leas... | #Picat | Picat | go ?=>
println("Months with five weekends:"),
FiveWeekends = [ [Year,Month] : Year in 1900..2100, Month in [1,3,5,7,8,10,12], dow(Year,Month,1) == 5],
WLen = FiveWeekends.len,
println(take(FiveWeekends,5)),
println("..."),
println(drop(FiveWeekends,WLen-5)),
println(len=WLen),
nl,
println("Years w/o... | Give a code snippet in #Picat
The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property (ther... | christopher/rosetta-code | |
http://rosettacode.org/wiki/McNuggets_problem | McNuggets problem | Wikipedia
The McNuggets version of the coin problem was introduced by Henri Picciotto,
who included it in his algebra textbook co-authored with Anita Wah. Picciotto
thought of the application in the 1980s while dining with his son at
McDonald's, working the problem out on a napkin. A McNugget number is
the total number... | #Elixir | Elixir | defmodule Mcnugget do
def solve(limit) do
0..limit
|> MapSet.new()
|> MapSet.difference(
for(
x <- 0..limit,
y <- 0..limit,
z <- 0..limit,
Integer.mod(x, 6) == 0,
Integer.mod(y, 9) == 0,
Integer.mod(z, 20) == 0,
x + y + z <= limit,
into... | Give a code snippet in #Elixir
Wikipedia
The McNuggets version of the coin problem was introduced by Henri Picciotto,
who included it in his algebra textbook co-authored with Anita Wah. Picciotto
thought of the application in the 1980s while dining with his son at
McDonald's, working the problem out on a napkin. A McN... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Write_a_PPM_file | Bitmap/Write a PPM file | Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| #LiveCode | LiveCode |
export image "test" to file "~/Test.PPM" as paint -- paint format is one of PBM, PGM, or PPM
| Give a code snippet in #LiveCode
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size_distribution | File size distribution | Task
Beginning from the current directory, or optionally from a directory specified as a command-line argument, determine how many files there are of various sizes in a directory hierarchy.
My suggestion is to sort by logarithmn of file size, since a few bytes here or there, or even a factor of two or three, may no... | #Action.21 | Action! | INCLUDE "D2:PRINTF.ACT" ;from the Action! Tool Kit
PROC SizeDistribution(CHAR ARRAY filter INT ARRAY limits,counts BYTE count)
CHAR ARRAY line(255),tmp(4)
INT size
BYTE i,dev=[1]
FOR i=0 TO count-1
DO
counts(i)=0
OD
Close(dev)
Open(dev,filter,6)
DO
InputSD(dev,line)
IF line(0)=0 THEN... | Give a code snippet in #Action.21
Task
Beginning from the current directory, or optionally from a directory specified as a command-line argument, determine how many files there are of various sizes in a directory hierarchy.
My suggestion is to sort by logarithmn of file size, since a few bytes here or there, or ev... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Sleep_sort | Sorting algorithms/Sleep sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Euphoria | Euphoria | include get.e
integer count
procedure sleeper(integer key)
? key
count -= 1
end procedure
sequence s, val
atom task
s = command_line()
s = s[3..$]
if length(s)=0 then
puts(1,"Nothing to sort.\n")
else
count = 0
for i = 1 to length(s) do
val = value(s[i])
if val[1] = GET_SUCCE... | Give a code snippet in #Euphoria
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delete_a_file | Delete a file | Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #GAP | GAP | # Apparently GAP can only remove a file, not a directory
RemoveFile("input.txt");
# true
RemoveFile("docs");
# fail | Give a code snippet in #GAP
Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Rock-paper-scissors | Rock-paper-scissors | Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner is decided by a set of rules:
... | #TI-83_BASIC | TI-83 BASIC | PROGRAM:RPS
:{0,0,0}→L1
:{0,0,0}→L2
:Lbl ST
:Disp "R/P/S"
:Disp "1/2/3"
:Lbl EC
:Input A
:If A>3 or A<1
:Then
:Goto NO
:End
:randInt(1,3+L1(1)+L1(2)+L1(3)→C
:If C≤1+L1(1)
:Then
:2→B
:Goto NS
:End
:If C>2+L1(2)
:Then
:1→B
:Else
:3→B
:End
:Lbl NS
:L1(A)+1→L1(A)
:If A=B
:Then
:Disp "TIE GAME"
:L2(3)+1→L2(3)
:Goto TG
:End
... | Give a code snippet in #TI-83_BASIC
Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #XLISP | XLISP | (FOR-EACH PRINT '(CYRUS CAMBYSES DARIUS XERXES ARTAXERXES)) | Give a code snippet in #XLISP
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bulls_and_cows/Player | Bulls and cows/Player | Task
Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts.
One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equ... | #Java | Java |
public class BullsAndCowsPlayerGame {
private static int count;
private static Console io = System.console();
private final GameNumber secret;
private List<AutoGuessNumber> pool = new ArrayList<>();
public BullsAndCowsPlayerGame(GameNumber secret) {
this.secret = secret;
fill... | Give a code snippet in #Java
Task
Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts.
One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_8-ball | Magic 8-ball | Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformatics/base count
Count occurren... | #Phix | Phix | with javascript_semantics
constant answers = {"As I see it, yes", "Ask again later", "You may rely on it",
"Without a doubt", "Don't bet on it", "Outlook not so good",
"Signs point to yes", "It is decidedly so", "It is certain",
"Better not tell you now", "My... | Give a code snippet in #Phix
Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I before E except after C
Bioinformat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game/Solve | 24 game/Solve | task
Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game.
Show examples of solutions generated by the program.
Related task
Arithmetic Evaluator
| #Elixir | Elixir | defmodule Game24 do
@expressions [ ["((", "", ")", "", ")", ""],
["(", "(", "", "", "))", ""],
["(", "", ")", "(", "", ")"],
["", "((", "", "", ")", ")"],
["", "(", "", "(", "", "))"] ]
def solve(digits) do
dig_perm = permute(digits) |> Enum.... | Give a code snippet in #Elixir
task
Write a program that takes four digits, either from user input or by random generation, and computes arithmetic expressions following the rules of the 24 game.
Show examples of solutions generated by the program.
Related task
Arithmetic Evaluator
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Cocktail_sort_with_shifting_bounds | Sorting algorithms/Cocktail sort with shifting bounds |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #FreeBASIC | FreeBASIC |
Sub cocktailShakerSort(bs() As Long)
Dim As Long i, lb = Lbound(bs), ub = Ubound(bs) -1
Dim As Long newlb, newub, tmp
Do While lb <= ub
newlb = ub
newub = lb
For i = lb To ub
If bs(i) > bs(i + 1) Then
tmp = bs(i): bs(i) = bs(i + 1): bs(i + 1) = tmp
... | Give a code snippet in #FreeBASIC
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quic... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_in_factors | Count in factors | Task
Write a program which counts up from 1, displaying each number as the multiplication of its prime factors.
For the purpose of this task, 1 (unity) may be shown as itself.
Example
2 is prime, so it would be shown as itself.
6 is not prime; it would be shown as
2
×
3
{\di... | #XPL0 | XPL0 | include c:\cxpl\codes;
int N0, N, F;
[N0:= 1;
repeat IntOut(0, N0); Text(0, " = ");
F:= 2; N:= N0;
repeat if rem(N/F) = 0 then
[if N # N0 then Text(0, " * ");
IntOut(0, F);
N:= N/F;
]
... | Give a code snippet in #XPL0
Task
Write a program which counts up from 1, displaying each number as the multiplication of its prime factors.
For the purpose of this task, 1 (unity) may be shown as itself.
Example
2 is prime, so it would be shown as itself.
6 is not prime; it would ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primality_by_trial_division | Primality by trial division | Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other loops are allowed.
Related tasks
... | #MATLAB | MATLAB | function isPrime = primalityByTrialDivision(n)
if n == 2
isPrime = true;
return
elseif (mod(n,2) == 0) || (n <= 1)
isPrime = false;
return
end
%First n mod (3 to sqrt(n)) is taken. This will be a vector where the
%first element is equal to n mod 3 and the last ele... | Give a code snippet in #MATLAB
Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formal_power_series | Formal power series | A power series is an infinite sum of the form
a
0
+
a
1
⋅
x
+
a
2
⋅
x
2
+
a
3
⋅
x
3
+
⋯
{\displaystyle a_{0}+a_{1}\cdot x+a_{2}\cdot x^{2}+a_{3}\cdot x^{3}+\cdots }
The ai are called the coefficients of the series. Such sums can be added, multiplied etc., where the new coefficients of ... | #Phix | Phix | with javascript_semantics
enum FPS_UNDEF = 0,
FPS_CONST,
FPS_ADD,
FPS_SUB,
FPS_MUL,
FPS_DIV,
FPS_DERIV,
FPS_INT,
FPS_MAX=$
type fps_type(integer f)
return f>=FPS_UNDEF and f<=FPS_MAX
end type
enum FPS_TYPE, FPS_S1, FPS_S2, FPS_A0
sequence fpss = {}
type fps(object id)
... | Give a code snippet in #Phix
A power series is an infinite sum of the form
a
0
+
a
1
⋅
x
+
a
2
⋅
x
2
+
a
3
⋅
x
3
+
⋯
{\displaystyle a_{0}+a_{1}\cdot x+a_{2}\cdot x^{2}+a_{3}\cdot x^{3}+\cdots }
The ai are called the coefficients of the series. Such sums can be added, multiplied etc., ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rate_counter | Rate counter | Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplish these goals:
Run N seconds worth... | #Fortran | Fortran | DO I = FIRST,LAST
IF (PROGRESSNOTE((I - FIRST)/(LAST - FIRST + 1.0))) WRITE (6,*) "Reached ",I,", towards ",LAST
...much computation...
END DO | Give a code snippet in #Fortran
Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplish t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Split_a_character_string_based_on_change_of_character | Split a character string based on change of character |
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly). The same applies
to commas.
Fo... | #AutoHotkey | AutoHotkey | Split_Change(str){
for i, v in StrSplit(str)
res .= (v=prev) ? v : (res?", " :"") v , prev := v
return res
} | Give a code snippet in #AutoHotkey
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly).... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #BCPL | BCPL | get "libhdr"
let reduce(f, v, len, seed) =
len = 0 -> seed,
reduce(f, v+1, len-1, f(!v, seed))
let start() be
$( let add(x, y) = x+y
let mul(x, y) = x*y
let nums = table 1,2,3,4,5,6,7
writef("%N*N", reduce(add, nums, 7, 0))
writef("%N*N", reduce(mul, nums, 7, 1))
$) | Give a code snippet in #BCPL
Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitcoin/address_validation | Bitcoin/address validation | Bitcoin/address validation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Write a program that takes a bitcoin address as argument,
and checks whether or not this address is valid.
A bitcoin address uses a base58 encoding, which uses an alphabet of th... | #C | C | #include <stdio.h>
#include <string.h>
#include <openssl/sha.h>
const char *coin_err;
#define bail(s) { coin_err = s; return 0; }
int unbase58(const char *s, unsigned char *out) {
static const char *tmpl = "123456789"
"ABCDEFGHJKLMNPQRSTUVWXYZ"
"abcdefghijkmnopqrstuvwxyz";
int i, j, c;
const char *p;
mems... | Give a code snippet in #C
Bitcoin/address validation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Write a program that takes a bitcoin address as argument,
and checks whether or not this address is valid.
A bitcoin address uses a base58 encoding, w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jensen%27s_Device | Jensen's Device | Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGOL 60 Report.
The following pr... | #AppleScript | AppleScript | set i to 0
on jsum(i, lo, hi, term)
set {temp, i's contents} to {0, lo}
repeat while i's contents ≤ hi
set {temp, i's contents} to {temp + (term's f(i)), (i's contents) + 1}
end repeat
return temp
end jsum
script term_func
on f(i)
return 1 / i
end f
end script
return jsum(a... | Give a code snippet in #AppleScript
Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_comparison | String 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 |... | #Nim | Nim | import strutils
var s1: string = "The quick brown"
var s2: string = "The Quick Brown"
echo("== : ", s1 == s2)
echo("!= : ", s1 != s2)
echo("< : ", s1 < s2)
echo("<= : ", s1 <= s2)
echo("> : ", s1 > s2)
echo(">= : ", s1 >= s2)
# cmpIgnoreCase(a, b) => 0 if a == b; < 0 if a < b; > 0 if a > b
echo("cmpIgnoreCase :", s1.... | Give a code snippet in #Nim
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
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Burrows%E2%80%93Wheeler_transform | Burrows–Wheeler transform |
This page uses content from Wikipedia. The original article was at Burrows–Wheeler_transform. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Burrows–Wheeler transform (BWT, also called block-s... | #Groovy | Groovy | class BWT {
private static final String STX = "\u0002"
private static final String ETX = "\u0003"
private static String bwt(String s) {
if (s.contains(STX) || s.contains(ETX)) {
throw new IllegalArgumentException("String cannot contain STX or ETX")
}
String ss = STX +... | Give a code snippet in #Groovy
This page uses content from Wikipedia. The original article was at Burrows–Wheeler_transform. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Burrows–Wheeler tra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_manipulation | Date manipulation | Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| #Raku | Raku | my @month = <January February March April May June July August September October November December>;
my %month = flat (@month Z=> ^12), (@month».substr(0,3) Z=> ^12), 'Sept' => 8;
grammar US-DateTime {
rule TOP { <month> <day>','? <year>','? <time> <tz> }
token month {
(\w+)'.'? { make %month{$0} // die "... | Give a code snippet in #Raku
Task
Given the date string "March 7 2009 7:30pm EST",
output the time 12 hours later in any human-readable format.
As extra credit, display the resulting time in a time zone different from your own.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Tau_number | Tau number | A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
| #Wren | Wren | import "/math" for Int
import "/fmt" for Fmt
System.print("The first 100 tau numbers are:")
var count = 0
var i = 1
while (count < 100) {
var tf = Int.divisors(i).count
if (i % tf == 0) {
Fmt.write("$,5d ", i)
count = count + 1
if (count % 10 == 0) System.print()
}
i = i + 1
} | Give a code snippet in #Wren
A Tau number is a positive integer divisible by the count of its positive divisors.
Task
Show the first 100 Tau numbers.
The numbers shall be generated during run-time (i.e. the code may not contain string literals, sets/arrays of integers, or alike).
Related task
Tau function
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #HyperTalk | HyperTalk | on BeerSong99
BottlesOfBeer 99
end BeerSong99
on OutputBeerLyric beerString
if ( beerString is "<reset>" ) then
put empty into cd fld "beer song"
else
put beerString & return after cd fld "beer song"
end if
end OutputBeerLyric
on BottlesOfBeer bottleCount
put bottleCount into initialCount
Output... | Give a code snippet in #HyperTalk
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Animation | Animation |
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task demonstrates this.
Task
Creat... | #Haskell | Haskell | import Graphics.HGL.Units (Time, Point, Size, )
import Graphics.HGL.Draw.Monad (Graphic, )
import Graphics.HGL.Draw.Text
import Graphics.HGL.Draw.Font
import Graphics.HGL.Window
import Graphics.HGL.Run
import Graphics.HGL.Utils
import Control.Exception (bracket, )
runAnim = runGraphics $
bracket
(openWindowEx "B... | Give a code snippet in #Haskell
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #BASIC | BASIC | DECLARE SUB quicksort (arr() AS INTEGER, leftN AS INTEGER, rightN AS INTEGER)
DIM q(99) AS INTEGER
DIM n AS INTEGER
RANDOMIZE TIMER
FOR n = 0 TO 99
q(n) = INT(RND * 9999)
NEXT
OPEN "output.txt" FOR OUTPUT AS 1
FOR n = 0 TO 99
PRINT #1, q(n),
NEXT
PRINT #1,
quicksort q(), 0, 99
FO... | Give a code snippet in #BASIC
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #Factor | Factor | USING: checksums checksums.sha io math.parser ;
"Rosetta code" sha-256 checksum-bytes bytes>hex-string print | Give a code snippet in #Factor
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b7... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_two_triangles_overlap | Determine if two triangles overlap | Determining if two triangles in the same plane overlap is an important topic in collision detection.
Task
Determine which of these pairs of triangles overlap in 2D:
(0,0),(5,0),(0,5) and (0,0),(5,0),(0,6)
(0,0),(0,5),(5,0) and (0,0),(0,5),(5,0)
(0,0),(5,0),(0,5) and (-10,0),(-5,0),(-1,6)... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | p1 = Polygon@{{0, 0}, {5, 0}, {0, 5}};
p2 = Polygon@{{0, 0}, {5, 0}, {0, 6}};
! RegionDisjoint[p1, p2]
p1 = Polygon@{{0, 0}, {0, 5}, {5, 0}};
p2 = Polygon@{{0, 0}, {0, 5}, {5, 0}};
! RegionDisjoint[p1, p2]
p1 = Polygon@{{0, 0}, {5, 0}, {0, 5}};
p2 = Polygon@{{-10, 0}, {-5, 0}, {-1, 6}};
! RegionDisjoint[p1, p2]
p... | Give a code snippet in #Mathematica.2FWolfram_Language
Determining if two triangles in the same plane overlap is an important topic in collision detection.
Task
Determine which of these pairs of triangles overlap in 2D:
(0,0),(5,0),(0,5) and (0,0),(5,0),(0,6)
(0,0),(0,5),(5,0) and (0,0),(0,5),(5... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #PL.2FM | PL/M | IF 0 THEN /* THIS WON'T RUN */;
IF 1 THEN /* THIS WILL */;
IF 2 THEN /* THIS WON'T */;
IF 3 THEN /* THIS WILL */; | Give a code snippet in #PL.2FM
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #Python | Python | >>> while True:
k = float(input('K ? '))
print("%g Kelvin = %g Celsius = %g Fahrenheit = %g Rankine degrees."
% (k, k - 273.15, k * 1.8 - 459.67, k * 1.8))
K ? 21.0
21 Kelvin = -252.15 Celsius = -421.87 Fahrenheit = 37.8 Rankine degrees.
K ? 222.2
222.2 Kelvin = -50.95 Celsius = -59.71 Fahrenheit ... | Give a code snippet in #Python
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #ReScript | ReScript | Js.String2.length("abcd") == 4 | Give a code snippet in #ReScript
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runge-Kutta_method | Runge-Kutta method | Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equation has an exact solution:
... | #APL | APL |
∇RK4[⎕]∇
∇
[0] Z←R(Y¯ RK4)Y;T;YN;TN;∆T;∆Y1;∆Y2;∆Y3;∆Y4
[1] (T R ∆T)←R
[2] LOOP:→(R≤TN←¯1↑T)/EXIT
[3] ∆Y1←∆T×TN Y¯ YN←¯1↑Y
[4] ∆Y2←∆T×(TN+∆T÷2)Y¯ YN+∆Y1÷2
[5] ∆Y3←∆T×(TN+∆T÷2)Y¯ YN+∆Y2÷2
[6] ∆Y4←∆T×(TN+∆T)Y¯ YN+∆Y3
[7] Y←Y,YN+(∆Y1+(2×∆Y2)+(2×∆Y3)+∆Y4)÷6
[8] T←T,TN+∆T
[9] →LOOP
[10] EXIT:Z←... | Give a code snippet in #APL
Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Playing_cards | Playing cards | Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current contents of a deck
Each card mu... | #K | K | v:"A23456789TJQK" / values
s:"SHCD" / suites
/ create a new deck
newdeck:{deck::,/s,'\:v}
newdeck(); | Give a code snippet in #K
Task
Create a data structure and the associated methods to define and manipulate a deck of playing cards.
The deck should contain 52 unique cards.
The methods must include the ability to:
make a new deck
shuffle (randomize) the deck
deal from the deck
print the current conte... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ordered_words | Ordered words | An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locally assume that you have download... | #BaCon | BaCon | 'Ordered words - improved version
OPTION COLLAPSE TRUE
list$ = LOAD$("unixdict.txt")
FOR word$ IN list$ STEP NL$
term$ = EXTRACT$(SORT$(EXPLODE$(word$, 1)), " ")
IF word$ = term$ THEN
IF LEN(term$) > MaxLen THEN
MaxLen = LEN(term$)
result$ = word$
ELIF LEN(term$) ... | Give a code snippet in #BaCon
An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locall... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #Modula-3 | Modula-3 | LOOP
IO.Put("SPAM\n");
END; | Give a code snippet in #Modula-3
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #CMake | CMake | set(list one.c two.c three.c)
foreach(file ${list})
message(${file})
endforeach(file) | Give a code snippet in #CMake
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #Phix | Phix | with javascript_semantics
setd("one",1)
setd(2,"duo")
setd({3,4},{5,"six"})
function visitor(object key, object data, object /*userdata*/)
?{key,data}
return 1 -- (continue traversal)
end function
traverse_dict(routine_id("visitor"))
| Give a code snippet in #Phix
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Comp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar tricker... | #Processing | Processing | println("hello world");
line(0, 0, width, height); | Give a code snippet in #Processing
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven langua... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Make_directory_path | Make directory path | Task
Create a directory and any missing parents.
This task is named after the posix mkdir -p command, and several libraries which implement the same behavior.
Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect.
If the directory already exists, return succe... | #D | D | import std.stdio;
void main() {
makeDir("parent/test");
}
/// Manual implementation of what mkdirRecurse in std.file does.
void makeDir(string path) out {
import std.exception : enforce;
import std.file : exists;
enforce(path.exists, "Failed to create the requested directory.");
} body {
import ... | Give a code snippet in #D
Task
Create a directory and any missing parents.
This task is named after the posix mkdir -p command, and several libraries which implement the same behavior.
Please implement a function of a single path string (for example ./path/to/dir) which has the above side-effect.
If the directory a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #Common_Lisp | Common Lisp | (loop for i from 1 do (print i)) | Give a code snippet in #Common_Lisp
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementati... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #Batch_File | Batch File | @echo off
setlocal enabledelayedexpansion
echo.
::Task #1
call :hailstone 111
echo Task #1: (Start:!sav!)
echo !seq!
echo.
echo Sequence has !cnt! elements.
echo.
::Task #2
call :hailstone 27
echo Task #2: (Start:!sav!)
echo !seq!
echo.
echo Sequence has !cnt! elements.
echo.
pause>nul
exit /b 0
::The Function
:hailst... | Give a code snippet in #Batch_File
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inheritance/Single | Inheritance/Single | This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent types.
Usually inherited properties... | #JavaScript | JavaScript | function Animal() {
// ...
} | Give a code snippet in #JavaScript
This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_brackets | Balanced brackets | Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nest.
Examples
(empty) ... | #Julia | Julia | using Printf
function balancedbrackets(str::AbstractString)
i = 0
for c in str
if c == '[' i += 1 elseif c == ']' i -=1 end
if i < 0 return false end
end
return i == 0
end
brackets(n::Integer) = join(shuffle(collect(Char, "[]" ^ n)))
for (test, pass) in map(x -> (x, balancedbracket... | Give a code snippet in #Julia
Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lucas-Lehmer_test | Lucas-Lehmer test | Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
−
2
{\displaystyle S(n+1)=(... | #AWK | AWK |
# syntax: GAWK -f LUCAS-LEHMER_TEST.AWK
# converted from Pascal
BEGIN {
printf("Mersenne primes:")
n = 1
for (exponent=2; exponent<=32; exponent++) {
s = (exponent == 2) ? 0 : 4
n = (n+1)*2-1
for (i=1; i<=exponent-2; i++) {
s = (s*s-2)%n
}
if (s == 0) {
printf... | Give a code snippet in #AWK
Lucas-Lehmer Test:
for
p
{\displaystyle p}
an odd prime, the Mersenne number
2
p
−
1
{\displaystyle 2^{p}-1}
is prime if and only if
2
p
−
1
{\displaystyle 2^{p}-1}
divides
S
(
p
−
1
)
{\displaystyle S(p-1)}
where
S
(
n
+
1
)
=
(
S
(
n
)
)
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Biorhythms | Biorhythms | For a while in the late 70s, the pseudoscience of biorhythms was popular enough to rival astrology, with kiosks in malls that would give you your weekly printout. It was also a popular entry in "Things to Do with your Pocket Calculator" lists. You can read up on the history at Wikipedia, but the main takeaway is that u... | #Go | Go | package main
import (
"fmt"
"log"
"math"
"time"
)
const layout = "2006-01-02" // template for time.Parse
var cycles = [3]string{"Physical day ", "Emotional day", "Mental day "}
var lengths = [3]int{23, 28, 33}
var quadrants = [4][2]string{
{"up and rising", "peak"},
{"up but falling", "t... | Give a code snippet in #Go
For a while in the late 70s, the pseudoscience of biorhythms was popular enough to rival astrology, with kiosks in malls that would give you your weekly printout. It was also a popular entry in "Things to Do with your Pocket Calculator" lists. You can read up on the history at Wikipedia, but... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Define_a_primitive_data_type | Define a primitive data type | Demonstrate how to define a type that behaves like an integer but has a lowest valid value of 1 and a highest valid value of 10. Include all bounds checking you need to write, or explain how the compiler or interpreter creates those bounds checks for you.
| #Julia | Julia | struct LittleInt <: Integer
val::Int8
function LittleInt(n::Real)
1 ≤ n ≤ 10 || throw(ArgumentError("LittleInt number must be in [1, 10]"))
return new(Int8(n))
end
end
Base.show(io::IO, x::LittleInt) = print(io, x.val)
Base.convert(::Type{T}, x::LittleInt) where T<:Number = convert(T, x.val)... | Give a code snippet in #Julia
Demonstrate how to define a type that behaves like an integer but has a lowest valid value of 1 and a highest valid value of 10. Include all bounds checking you need to write, or explain how the compiler or interpreter creates those bounds checks for you.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #Clojure | Clojure | (max 1 2 3 4) ; evaluates to 4
;; If the values are already in a collection, use apply:
(apply max [1 2 3 4]) ; evaluates to 4 | Give a code snippet in #Clojure
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| christopher/rosetta-code | |
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 ... | #Erlang | Erlang |
2> S = " ad
2> 123
2> the end".
3> io:fwrite( S ).
ad
123
the end
| Give a code snippet in #Erlang
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) follow... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Closures/Value_capture | Closures/Value capture | Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.
Display the result of runnin... | #LFE | LFE |
> (set funcs (list-comp ((<- m (lists:seq 1 10)))
(lambda () (math:pow m 2))))
| Give a code snippet in #LFE
Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Java | Java | import java.io.BufferedReader;
import java.io.FileReader;
/**
* Reads a file line by line, processing each line.
*
* @author $Author$
* @version $Revision$
*/
public class ReadFileByLines {
private static void processLine(int lineNo, String line) {
// ...
}
public static void main(String[]... | Give a code snippet in #Java
Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Tic-tac-toe | Tic-tac-toe |
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWorld™, Tic-Tac-Toe game.
Wikipedi... | #PHP | PHP |
<?php
const BOARD_NUM = 9;
const ROW_NUM = 3;
$EMPTY_BOARD_STR = str_repeat('.', BOARD_NUM);
function isGameOver($board, $pin) {
$pat =
'/X{3}|' . //Horz
'X..X..X..|' . //Vert Left
'.X..X..X.|' . //Vert Middle
'..X..X..X|' . //Vert Right
'..X.X.X..|' . //Diag TL->BR
'X...X...X|' . //Diag TR->BL
'[^\... | Give a code snippet in #PHP
Task
Play a game of tic-tac-toe.
Ensure that legal moves are played and that a winning position is notified.
Tic-tac-toe is also known as:
naughts and crosses
tic tac toe
tick tack toe
three in a row
tres en rayo and
Xs and Os
See also
MathWorld™, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #C | C |
#include <stdio.h>
int main()
{
const char *fruit[2] = { "apples", "oranges" };
// Acquire the length of the array by dividing the size of all elements (found
// with sizeof(fruit)) by the size of the first element.
// Note that since the array elements are pointers to null-terminated charac... | Give a code snippet in #C
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #Picat | Picat | main =>
L = ["apple", "orange"],
println(len(L))),
println(length(L)),
println(L.len),
println(L.length). | Give a code snippet in #Picat
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cholesky_decomposition | Cholesky decomposition | Every symmetric, positive definite matrix A can be decomposed into a product of a unique lower triangular matrix L and its transpose:
A
=
L
L
T
{\displaystyle A=LL^{T}}
L
{\displaystyle L}
is called the Cholesky factor of
A
{\displaystyle A}
, and can be interpreted as a generalized square r... | #JavaScript | JavaScript |
const cholesky = function (array) {
const zeros = [...Array(array.length)].map( _ => Array(array.length).fill(0));
const L = zeros.map((row, r, xL) => row.map((v, c) => {
const sum = row.reduce((s, _, i) => i < c ? s + xL[r][i] * xL[c][i] : s, 0);
return xL[r][c] = c < r + 1 ? r === c ? Math.sqrt(array[r][r] - ... | Give a code snippet in #JavaScript
Every symmetric, positive definite matrix A can be decomposed into a product of a unique lower triangular matrix L and its transpose:
A
=
L
L
T
{\displaystyle A=LL^{T}}
L
{\displaystyle L}
is called the Cholesky factor of
A
{\displaystyle A}
, and can be i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jewels_and_stones | Jewels and stones | Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case letters. However, in the case ... | #D | D | import std.algorithm;
import std.stdio;
int countJewels(string s, string j) {
int count;
foreach (c; s) {
if (j.canFind(c)) {
count++;
}
}
return count;
}
void main() {
countJewels("aAAbbbb", "aA").writeln;
countJewels("ZZ", "z").writeln;
} | Give a code snippet in #D
Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case let... | christopher/rosetta-code | |
http://rosettacode.org/wiki/I_before_E_except_after_C | I before E except after C | The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individually:
"I before E when not pre... | #Delphi | Delphi |
program I_before_E_except_after_C;
uses
System.SysUtils, System.IOUtils;
function IsOppPlausibleWord(w: string): Boolean;
begin
if ((not w.Contains('c')) and (w.Contains('ei'))) then
exit(True);
if (w.Contains('cie')) then
exit(True);
exit(false);
end;
function IsPlausibleWord(w: string): Bo... | Give a code snippet in #Delphi
The phrase "I before E, except after C" is a
widely known mnemonic which is supposed to help when spelling English words.
Task
Using the word list from http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
check if the two sub-clauses of the phrase are plausible individual... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #FBSL | FBSL |
#APPTYPE CONSOLE
SUB MAIN()
BlockCheck("A")
BlockCheck("BARK")
BlockCheck("BooK")
BlockCheck("TrEaT")
BlockCheck("comMON")
BlockCheck("sQuAd")
BlockCheck("Confuse")
pause
END SUB
FUNCTION BlockCheck(str)
PRINT str " " iif( Blockable( str ), "can", "cannot" ) " be spelled with blocks."
END FUNCTION
FUNCTI... | Give a code snippet in #FBSL
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #Oz | Oz | declare
NumDoors = 100
NumPasses = 100
fun {NewDoor} closed end
fun {Toggle Door}
case Door of closed then open
[] open then closed
end
end
fun {Pass Doors I}
{List.mapInd Doors
fun {$ Index Door}
if Index mod I == 0 then {Toggle Door}
else Door
end... | Give a code snippet in #Oz
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...),... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Four_bit_adder | Four bit adder | Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands ... | #Clojure | Clojure |
(ns rosettacode.adder
(:use clojure.test))
(defn xor-gate [a b]
(or (and a (not b)) (and b (not a))))
(defn half-adder [a b]
"output: (S C)"
(cons (xor-gate a b) (list (and a b))))
(defn full-adder [a b c]
"output: (C S)"
(let [HA-ca (half-adder c a)
HA-ca->sb (half-adder (first HA-ca) b)]
... | Give a code snippet in #Clojure
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be mad... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Coloured_text | Terminal control/Coloured text | Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to cause blinking or flashing (if ... | #zkl | zkl | fcn table(title,mode){
println("\n\e[1m%s\e[m\n bg\t fg".fmt(title));
foreach b in ([40..48].chain([100..107])){
print("%3d\t\e[%s%dm".fmt(b,mode,b));
foreach f in ([30..38].chain([90..97])){ print("\e[%dm%3d ".fmt(f,f)) }
println("\e[m");
}
}
table("normal ( ESC[22m or ESC[m )", "22;");
... | Give a code snippet in #zkl
Task
Display a word in various colours on the terminal.
The system palette, or colours such as Red, Green, Blue, Magenta, Cyan, and Yellow can be used.
Optionally demonstrate:
How the system should determine if the terminal supports colour
Setting of the background colour
How to ca... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #Run_BASIC | Run BASIC | for i = 1 to 100
if happy(i) = 1 then
cnt = cnt + 1
PRINT cnt;". ";i;" is a happy number "
if cnt = 8 then end
end if
next i
FUNCTION happy(num)
while count < 50 and happy <> 1
num$ = str$(num)
count = count + 1
happy = 0
for i = 1 to len(num$)
happy = happy + val(mid$(num$,i,1)) ^ 2
next i
n... | Give a code snippet in #Run_BASIC
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endles... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Graphical | User input/Graphical |
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| #Processing | Processing | import javax.swing.JOptionPane;
int number = int(JOptionPane.showInputDialog ("Enter an Integer"));
println(number);
String string = JOptionPane.showInputDialog ("Enter a String");
println(string); | Give a code snippet in #Processing
In this task, the goal is to input a string and the integer 75000, from graphical user interface.
See also: User input/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_integer_array | Sort an integer array |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #EGL | EGL | program SortExample
function main()
test1 int[] = [1,-1,8,-8,2,-2,7,-7,3,-3,6,-6,9,-9,4,-4,5,-5,0];
test1.sort(sortFunction);
for(i int from 1 to test1.getSize())
SysLib.writeStdout(test1[i]);
end
end
function sortFunction(a any in, b any in) returns (int)
return (a as i... | Give a code snippet in #EGL
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #Stata | Stata | prog def multiply, return
args a b
return sca product=`a'*`b'
end
multiply 77 13
di r(product) | Give a code snippet in #Stata
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Closures/Value_capture | Closures/Value capture | Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.
Display the result of runnin... | #Pike | Pike | array funcs = ({});
foreach(enumerate(10);; int i)
{
funcs+= ({
lambda(int j)
{
return lambda()
{
return j*j;
};
}(i)
});
} | Give a code snippet in #Pike
Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.... | christopher/rosetta-code |
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