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
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http://rosettacode.org/wiki/Last_Friday_of_each_month | Last Friday of each month | Task
Write a program or a script that returns the date of the last Fridays of each month of a given year.
The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_fridays 2012
2012-01-27
2012-02-24
2012-03-30
2012-04-27
2012-05-25
20... | #Vlang | Vlang | import time
import os
fn main() {
mut year := 0
mut t := time.now()
year = os.input("Please select a year: ").int()
println("Last Fridays of each month of $year")
println("==================================")
for i in 1..13 {
mut j := time.month_days[i-1]
if i == 2 {
... | Give a code snippet in #Vlang
Task
Write a program or a script that returns the date of the last Fridays of each month of a given year.
The year may be given through any simple input method in your language (command line, std in, etc).
Example of an expected output:
./last_fridays 2012
2012-01-27
2012-02-24
2012... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ISBN13_check_digit | ISBN13 check digit | Task
Validate the check digit of an ISBN-13 code:
Multiply every other digit by 3.
Add these numbers and the other digits.
Take the remainder of this number after division by 10.
If it is 0, the ISBN-13 check digit is correct.
Use the following codes for testing:
978-1734314502 (good)
... | #Raku | Raku | sub check-digit ($isbn) {
(10 - (sum (|$isbn.comb(/<[0..9]>/)) »*» (1,3)) % 10).substr: *-1
}
{
my $check = .substr(*-1);
my $check-digit = check-digit .chop;
say "$_ : ", $check == $check-digit ??
'Good' !!
"Bad check-digit $check; should be $check-digit"
} for words <
978-173431... | Give a code snippet in #Raku
Task
Validate the check digit of an ISBN-13 code:
Multiply every other digit by 3.
Add these numbers and the other digits.
Take the remainder of this number after division by 10.
If it is 0, the ISBN-13 check digit is correct.
Use the following codes for testing:
9... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_entire_file | Write entire file | Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| #PicoLisp | PicoLisp | (out "file.txt"
(prinl "My string") ) | Give a code snippet in #PicoLisp
Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Metaprogramming | Metaprogramming | Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation.
For the purposes of this task, "support for metaprogramming" means any way the user can effect... | #OxygenBasic | OxygenBasic |
'EQUATES
% half 0.5
$ title "My Metaprogram"
'CONDITIONAL BLOCKS
#ifdef ...
...
#elseif ...
...
#else
...
#endif
'MACROS
'msdos-like
def sum
%1 + %2
end def
'C-like
#define sum(a,b) a + b
'native
macro sum(a,b)
a + b
end macro
'native macro functions
macro sum int(r,a,b)
r = a + b... | Give a code snippet in #OxygenBasic
Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation.
For the purposes of this task, "support for metaprogrammi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #ERRE | ERRE | PROGRAM CLASS_DEMO
CLASS QUEUE
LOCAL SP
LOCAL DIM STACK[100]
FUNCTION ISEMPTY()
ISEMPTY=(SP=0)
END FUNCTION
PROCEDURE INIT
SP=0
END PROCEDURE
PROCEDURE POP(->XX)
XX=STACK[SP]
SP=SP-1
END PROCEDURE
PROCEDURE PUSH(XX)
SP=SP+1
STACK[SP]=XX
END P... | Give a code snippet in #ERRE
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the or... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Verhoeff_algorithm | Verhoeff algorithm | Description
The Verhoeff algorithm is a checksum formula for error detection developed by the Dutch mathematician Jacobus Verhoeff and first published in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two adjacent digits, which was at t... | #Perl | Perl | #!/usr/bin/perl
use strict; # https://rosettacode.org/wiki/Verhoeff_algorithm
use warnings;
my @inv = qw(0 4 3 2 1 5 6 7 8 9);
my @d = map [ split ], split /\n/, <<END;
0 1 2 3 4 5 6 7 8 9
1 2 3 4 0 6 7 8 9 5
2 3 4 0 1 7 8 9 5 6
3 4 0 1 2 8 9 5 6 7
4 0 1 2 3 9 5 6 7 8
... | Give a code snippet in #Perl
Description
The Verhoeff algorithm is a checksum formula for error detection developed by the Dutch mathematician Jacobus Verhoeff and first published in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Farey_sequence | Farey sequence | The Farey sequence Fn of order n is the sequence of completely reduced fractions between 0 and 1 which, when in lowest terms, have denominators less than or equal to n, arranged in order of increasing size.
The Farey sequence is sometimes incorrectly called a Farey series.
Each Farey se... | #XPL0 | XPL0 | proc Farey(N); \Show Farey sequence for N
\Translation of Python program on Wikipedia:
int N, A, B, C, D, K, T;
[A:= 0; B:= 1; C:= 1; D:= N;
Text(0, "0/1");
while C <= N do
[K:= (N+B)/D;
T:= C;
C:= K*C - A;
A:= T;
T:= D;
D:= K*D - B;
B:= T;
ChOut(0, ^ ); IntOut(0, A);
C... | Give a code snippet in #XPL0
The Farey sequence Fn of order n is the sequence of completely reduced fractions between 0 and 1 which, when in lowest terms, have denominators less than or equal to n, arranged in order of increasing size.
The Farey sequence is sometimes incorrectly called a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dining_philosophers | Dining philosophers | The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eating spaghetti. They eat at a rou... | #Simula | Simula | COMMENT
! DEADLOCK IS PREVENTED BY REVERSING THE ORDER OF TAKING THE CHOPSTICKS FOR THE LAST PHILOSOPHER.
! THAT MEANS ALL PHILOSOPHERS FIRST TAKE THE LEFT CHOPSTICK, THEN THE RIGHT CHOPSTICK.
! BUT THE LAST PHILOSOPHER FIRST TAKES THE RIGHT CHOPSTICK, THEN THE LEFT.
!
! THE DETACH STATEMENT IN CLASS PHILOS... | Give a code snippet in #Simula
The dining philosophers problem illustrates non-composability of low-level synchronization primitives like semaphores. It is a modification of a problem posed by Edsger Dijkstra.
Five philosophers, Aristotle, Kant, Spinoza, Marx, and Russell (the tasks) spend their time thinking and eat... | 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... | #Phix | Phix | integer key
while get_key()!=-1 do end while -- flush
puts(1,"Your answer? (Y/N)")
while 1 do
key = upper(get_key())
if find(key,"YN") then exit end if
end while
printf(1,"\nYour response was %s\n",key)
| Give a code snippet in #Phix
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/Forward_difference | Forward difference | Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer elem... | #CoffeeScript | CoffeeScript |
forward_difference = (arr, n) ->
# Find the n-th order forward difference for arr using
# a straightforward recursive algorithm.
# Assume arr is integers and n <= arr.length.
return arr if n == 0
arr = forward_difference(arr, n-1)
(arr[i+1] - arr[i] for i in [0...arr.length - 1])
arr = [-1, 0, 1, 8, 27,... | Give a code snippet in #CoffeeScript
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #PowerShell | PowerShell |
function f ($y) {
$y*$y
}
function g (${function:f}, $y) {
(f $y)
}
| Give a code snippet in #PowerShell
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_entire_file | Write entire file | Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| #SenseTalk | SenseTalk | put "New String" into file "~/Desktop/myFile.txt" | Give a code snippet in #SenseTalk
Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| 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 ... | #Ruby | Ruby | my_dict = { "hello" => 13,
"world" => 31,
"!" => 71 }
# iterating over key-value pairs:
my_dict.each {|key, value| puts "key = #{key}, value = #{value}"}
# or
my_dict.each_pair {|key, value| puts "key = #{key}, value = #{value}"}
# iterating over keys:
my_dict.each_key {|key| puts "key = #{key}"}
# it... | Give a code snippet in #Ruby
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/Non-continuous_subsequences | Non-continuous subsequences | Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between the first and last elements of the subseque... | #Julia | Julia | using Printf, IterTools
import Base.IteratorSize, Base.iterate, Base.length
iscontseq(n::Integer) = count_zeros(n) == leading_zeros(n) + trailing_zeros(n)
iscontseq(n::BigInt) = !ismatch(r"0", rstrip(bin(n), '0'))
function makeint2seq(n::Integer)
idex = collect(1:n)
function int2seq(m::Integer)
... | Give a code snippet in #Julia
Consider some sequence of elements. (It differs from a mere set of elements by having an ordering among members.)
A subsequence contains some subset of the elements of this sequence, in the same order.
A continuous subsequence is one in which no elements are missing between the first an... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #TUSCRIPT | TUSCRIPT | $$ MODE TUSCRIPT
file="lines.txt"
ERROR/STOP OPEN (file,READ,-std-)
line2fetch=7 | Give a code snippet in #TUSCRIPT
Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort | Sorting algorithms/Bubble 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
... | #Oz | Oz | declare
proc {BubbleSort Arr}
proc {Swap I J}
Arr.J := (Arr.I := Arr.J) %% assignment returns the old value
end
IsSorted = {NewCell false}
MaxItem = {NewCell {Array.high Arr}-1}
in
for until:@IsSorted do
IsSorted := true
for I in {Array.low Arr}..@MaxItem do
... | Give a code snippet in #Oz
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/Bitmap/B%C3%A9zier_curves/Cubic | Bitmap/Bézier curves/Cubic | Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| #Lambdatalk | Lambdatalk |
Drawing a cubic bezier curve out of any SVG or CANVAS frame.
1) interpolating 4 points
The Bézier curve is defined as an array of 4 given points,
each defined as an array of 2 numbers.
The bezier function returns the point interpolating the 4 points.
{def bezier
{def bezier.interpol
{lambda {:a0 :a1 :a2 :a3... | Give a code snippet in #Lambdatalk
Using the data storage type defined on this page for raster images, and the draw_line function defined in this other one, draw a cubic bezier curve
(definition on Wikipedia).
| 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)... | #Vlang | Vlang | struct Point {
x f64
y f64
}
fn (p Point) str() string {
return "(${p.x:.1f}, ${p.y:.1f})"
}
struct Triangle {
mut:
p1 Point
p2 Point
p3 Point
}
fn (t Triangle) str() string {
return "Triangle $t.p1, $t.p2, $t.p3"
}
fn (t Triangle) det_2d() f64 {
return t.p1.x * (t.p2.y - t.p3.y) +
... | Give a code snippet in #Vlang
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) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Solve_a_Hidato_puzzle | Solve a Hidato puzzle | The task is to write a program which solves Hidato (aka Hidoku) puzzles.
The rules are:
You are given a grid with some numbers placed in it. The other squares in the grid will be blank.
The grid is not necessarily rectangular.
The grid may have holes in it.
The grid is always connected.
The number “1” is always ... | #Haskell | Haskell | {-# LANGUAGE TupleSections #-}
{-# LANGUAGE Rank2Types #-}
import qualified Data.IntMap as I
import Data.IntMap (IntMap)
import Data.List
import Data.Maybe
import Data.Time.Clock
data BoardProblem = Board
{ cells :: IntMap (IntMap Int)
, endVal :: Int
, onePos :: (Int, Int)
, givens :: [Int]
} deriving (S... | Give a code snippet in #Haskell
The task is to write a program which solves Hidato (aka Hidoku) puzzles.
The rules are:
You are given a grid with some numbers placed in it. The other squares in the grid will be blank.
The grid is not necessarily rectangular.
The grid may have holes in it.
The grid is always conn... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chernick%27s_Carmichael_numbers | Chernick's Carmichael numbers | In 1939, Jack Chernick proved that, for n ≥ 3 and m ≥ 1:
U(n, m) = (6m + 1) * (12m + 1) * Product_{i=1..n-2} (2^i * 9m + 1)
is a Carmichael number if all the factors are primes and, for n > 4, m is a multiple of 2^(n-4).
Example
U(3, m) = (6m + 1) * (12m + 1) * (18m + 1)
U(4, m) = U(3, m) * (2^2 * 9m + 1)... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | ClearAll[PrimeFactorCounts, U]
PrimeFactorCounts[n_Integer] := Total[FactorInteger[n][[All, 2]]]
U[n_, m_] := (6 m + 1) (12 m + 1) Product[2^i 9 m + 1, {i, 1, n - 2}]
FindFirstChernickCarmichaelNumber[n_Integer?Positive] :=
Module[{step, i, m, formula, value},
step = Ceiling[2^(n - 4)];
If[n > 5, step *= 5];
i ... | Give a code snippet in #Mathematica_.2F_Wolfram_Language
In 1939, Jack Chernick proved that, for n ≥ 3 and m ≥ 1:
U(n, m) = (6m + 1) * (12m + 1) * Product_{i=1..n-2} (2^i * 9m + 1)
is a Carmichael number if all the factors are primes and, for n > 4, m is a multiple of 2^(n-4).
Example
U(3, m) = (6m + 1) * (... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Break | Loops/Break | Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the loop.
If the number 10 is never gener... | #XBS | XBS | while(true){
set n:number = math.random(0,19);
log(`first: {n}`);
if(n==10){stop}
n = math.random(0,19);
log(`second: {n}`);
} | Give a code snippet in #XBS
Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the loop.
If... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_word/fractal | Fibonacci word/fractal |
The Fibonacci word may be represented as a fractal as described here:
(Clicking on the above website (hal.archives-ouvertes.fr) will leave a cookie.)
For F_wordm start with F_wordCharn=1
Draw a segment forward
If current F_wordChar is 0
Turn left if n is even
Turn right if n is odd
next n and iterate until e... | #Haskell | Haskell | import Data.List (unfoldr)
import Data.Bool (bool)
import Data.Semigroup (Sum(..), Min(..), Max(..))
import System.IO (writeFile)
fibonacciWord :: a -> a -> [[a]]
fibonacciWord a b = unfoldr (\(a,b) -> Just (a, (b, a <> b))) ([a], [b])
toPath :: [Bool] -> ((Min Int, Max Int, Min Int, Max Int), String)
toPath = fold... | Give a code snippet in #Haskell
The Fibonacci word may be represented as a fractal as described here:
(Clicking on the above website (hal.archives-ouvertes.fr) will leave a cookie.)
For F_wordm start with F_wordCharn=1
Draw a segment forward
If current F_wordChar is 0
Turn left if n is even
Turn right if n ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/GUI_enabling/disabling_of_controls | GUI enabling/disabling of controls | In addition to fundamental GUI component interaction, an application should
dynamically enable and disable GUI components, to give some guidance to the
user, and prohibit (inter)actions which are inappropriate in the current state
of the application.
Task
Similar to the task GUI component interaction, write a progr... | #Vala | Vala | bool validate_input(Gtk.Window window, string str){
int64 val;
bool ret = int64.try_parse(str,out val);;
if(!ret || str == ""){
var dialog = new Gtk.MessageDialog(window,
Gtk.DialogFlags.MODAL,
Gtk.MessageType.ER... | Give a code snippet in #Vala
In addition to fundamental GUI component interaction, an application should
dynamically enable and disable GUI components, to give some guidance to the
user, and prohibit (inter)actions which are inappropriate in the current state
of the application.
Task
Similar to the task GUI compon... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Arithmetic_mean | Averages/Arithmetic mean | Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin... | #AmigaE | AmigaE | PROC mean(l:PTR TO LONG)
DEF m, i, ll
ll := ListLen(l)
IF ll = 0 THEN RETURN 0.0
m := 0.0
FOR i := 0 TO ll-1 DO m := !m + l[i]
m := !m / (ll!)
ENDPROC m
PROC main()
DEF s[20] : STRING
WriteF('mean \s\n',
RealF(s,mean([1.0, 2.0, 3.0, 4.0, 5.0]), 2))
ENDPROC | Give a code snippet in #AmigaE
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an est... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Set_puzzle | Set puzzle | Set Puzzles are created with a deck of cards from the Set Game™. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up.
There are 81 cards in a deck.
Each card contains a unique variation of the following four features: color, symbol, number and shading.
there are... | #Elixir | Elixir | defmodule RC do
def set_puzzle(deal, goal) do
{puzzle, sets} = get_puzzle_and_answer(deal, goal, produce_deck)
IO.puts "Dealt #{length(puzzle)} cards:"
print_cards(puzzle)
IO.puts "Containing #{length(sets)} sets:"
Enum.each(sets, fn set -> print_cards(set) end)
end
defp get_puzzle_and_answe... | Give a code snippet in #Elixir
Set Puzzles are created with a deck of cards from the Set Game™. The object of the puzzle is to find sets of 3 cards in a rectangle of cards that have been dealt face up.
There are 81 cards in a deck.
Each card contains a unique variation of the following four features: color, symbol,... | 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
| #OCaml | OCaml | type expression =
| Const of float
| Sum of expression * expression (* e1 + e2 *)
| Diff of expression * expression (* e1 - e2 *)
| Prod of expression * expression (* e1 * e2 *)
| Quot of expression * expression (* e1 / e2 *)
let rec eval = function
| Const c -> c
| Sum (f, g) -> eval f +. eval... | Give a code snippet in #OCaml
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/Maze_solving | Maze solving | Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be used.
| #Emacs_Lisp | Emacs Lisp | (require 'cl-lib)
(cl-defstruct maze rows cols data)
(defmacro maze-pt (w r c)
`(+ (* (mod ,r (maze-rows ,w)) (maze-cols ,w))
(mod ,c (maze-cols ,w))))
(defmacro maze-ref (w r c)
`(aref (maze-data ,w) (maze-pt ,w ,r ,c)))
(defun new-maze (rows cols)
(setq rows (1+ rows)
cols (1+ cols))
(le... | Give a code snippet in #Emacs_Lisp
Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be use... | 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 ... | #HicEst | HicEst | REAL :: Fibonacci(10)
Fibonacci = ($==2) + Fibonacci($-1) + Fibonacci($-2)
WRITE(ClipBoard) Fibonacci ! 0 1 1 2 3 5 8 13 21 34 | Give a code snippet in #HicEst
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 ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evolutionary_algorithm | Evolutionary algorithm | Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of its argument to the target string.... | #Red | Red | Red[]
; allowed characters
alphabet: "ABCDEFGHIJKLMNOPQRSTUVWXYZ "
; target string
target: "METHINKS IT IS LIKE A WEASEL"
; parameter controlling the number of children
C: 10
; parameter controlling the evolution rate
RATE: 0.05
; compute closeness of 'string' to 'target'
fitness: function [string] [
sum: 0
r... | Give a code snippet in #Red
Starting with:
The target string: "METHINKS IT IS LIKE A WEASEL".
An array of random characters chosen from the set of upper-case letters together with the space, and of the same length as the target string. (Call it the parent).
A fitness function that computes the ‘closeness’ of its a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compiler/virtual_machine_interpreter | Compiler/virtual machine interpreter | A virtual machine implements a computer in software.
Task[edit]
Write a virtual machine interpreter. This interpreter should be able to run virtual
assembly language programs created via the task. This is a
byte-coded, 32-bit word stack based virtual machine.
The program should read input from a file and/or stdin, an... | #Common_Lisp | Common Lisp | #!/bin/sh
#|-*- mode:lisp -*-|#
#|
exec ros -Q -- $0 "$@"
|#
(progn ;;init forms
(ros:ensure-asdf)
#+quicklisp(ql:quickload '() :silent t)
)
(defpackage :ros.script.vm.3858678051
(:use :cl))
(in-package :ros.script.vm.3858678051)
;;;
;;; The Rosetta Code Virtual Machine, in Common Lisp.
;;;
;;; Notes:
;;;
;... | Give a code snippet in #Common_Lisp
A virtual machine implements a computer in software.
Task[edit]
Write a virtual machine interpreter. This interpreter should be able to run virtual
assembly language programs created via the task. This is a
byte-coded, 32-bit word stack based virtual machine.
The program should re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, o... | #ABAP | ABAP | report z_align no standard page header.
start-of-selection.
data: lt_strings type standard table of string,
lv_strings type string.
append: 'Given$a$text$file$of$many$lines,$where$fields$within$a$line$' to lt_strings,
'are$delineated$by$a$single$''dollar''$character,$write$a$program' to lt_strings,
... | Give a code snippet in #ABAP
Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #Factor | Factor | USING: math.text.utils lists lists.lazy ;
: niven? ( n -- ? ) dup 1 digit-groups sum mod 0 = ;
: first-n-niven ( n -- seq )
1 lfrom [ niven? ] lfilter ltake list>array ;
: next-niven ( n -- m ) 1 + [ dup niven? ] [ 1 + ] until ;
20 first-n-niven .
1000 next-niven . | Give a code snippet in #Factor
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Emacs_Lisp | Emacs Lisp |
;; Functional (most elegant and best suited to Lisp dialects):
(defun fact (n)
"Return the factorial of integer N, which require to be positive or 0."
;; Elisp won't do any type checking automatically, so
;; good practice would be doing that ourselves:
(if (not (and (integerp n) (>= n 0)))
(error "Funct... | Give a code snippet in #Emacs_Lisp
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Munchausen_numbers | Munchausen numbers | A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also see
The OEIS entry: A046253
The ... | #Haskell | Haskell | import Control.Monad (join)
import Data.List (unfoldr)
isMunchausen :: Integer -> Bool
isMunchausen =
(==)
<*> (sum . map (join (^)) . unfoldr digit)
digit 0 = Nothing
digit n = Just (r, q) where (q, r) = n `divMod` 10
main :: IO ()
main = print $ filter isMunchausen [1 .. 5000] | Give a code snippet in #Haskell
A Munchausen number is a natural number n the sum of whose digits (in base 10), each raised to the power of itself, equals n.
(Munchausen is also spelled: Münchhausen.)
For instance: 3435 = 33 + 44 + 33 + 55
Task
Find all Munchausen numbers between 1 and 5000.
Also see... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stem-and-leaf_plot | Stem-and-leaf plot | Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37 127 29 113 121 58 114 126 53 11... | #Elixir | Elixir | defmodule Stem_and_leaf do
def plot(data, leaf_digits\\1) do
multiplier = Enum.reduce(1..leaf_digits, 1, fn _,acc -> acc*10 end)
Enum.group_by(data, fn x -> div(x, multiplier) end)
|> Map.new(fn {k,v} -> {k, Enum.map(v, &rem(&1, multiplier)) |> Enum.sort} end)
|> print(leaf_digits)
end
defp prin... | Give a code snippet in #Elixir
Create a well-formatted stem-and-leaf plot from the following data set, where the leaves are the last digits:
12 127 28 42 39 113 42 18 44 118 44 37 113 124 37 48 127 36 29 31 125 139 131 115 105 132 104 123 35 113 122 42 117 119 58 109 23 105 63 27 44 105 99 41 128 121 116 125 32 61 37... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #Kotlin | Kotlin | // version 2.0
fun binomial(n: Int, k: Int) = when {
n < 0 || k < 0 -> throw IllegalArgumentException("negative numbers not allowed")
n == k -> 1L
else -> {
val kReduced = min(k, n - k) // minimize number of steps
var result = 1L
var numerator = n
var d... | Give a code snippet in #Kotlin
This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_join | Hash join | An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" algorithm, and demonstrate tha... | #C.2B.2B | C++ | #include <iostream>
#include <string>
#include <vector>
#include <unordered_map>
using tab_t = std::vector<std::vector<std::string>>;
tab_t tab1 {
// Age Name
{"27", "Jonah"}
, {"18", "Alan"}
, {"28", "Glory"}
, {"18", "Popeye"}
, {"28", "Alan"}
};
tab_t tab2 {
// Character Nemesis
{"Jonah", "Whales"}
, {"Jon... | Give a code snippet in #C.2B.2B
An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash joi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Display_an_outline_as_a_nested_table | Display an outline as a nested table |
Display an outline as a nested table.
Parse the outline to a tree,
count the leaves descending from each node,
and write out a table with 'colspan' values
measuring the indent of each line,
translating the indentation to a nested structure,
and padding the tree to even depth.
defining the width of a ... | #Python | Python | """Display an outline as a nested table. Requires Python >=3.6."""
import itertools
import re
import sys
from collections import deque
from typing import NamedTuple
RE_OUTLINE = re.compile(r"^((?: |\t)*)(.+)$", re.M)
COLORS = itertools.cycle(
[
"#ffffe6",
"#ffebd2",
"#f0fff0",
... | Give a code snippet in #Python
Display an outline as a nested table.
Parse the outline to a tree,
count the leaves descending from each node,
and write out a table with 'colspan' values
measuring the indent of each line,
translating the indentation to a nested structure,
and padding the tree to even d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mode | Averages/Mode | Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if possible. If it is not appropriat... | #PL.2FI | PL/I | av: procedure options (main); /* 28 October 2013 */
declare x(10) fixed binary static initial (1, 4, 2, 6, 2, 5, 6, 2, 4, 2);
declare f(32767) fixed binary;
declare (j, n, max, value) fixed binary;
declare i fixed;
n = hbound(x,1);
do i = 1 to n;
j = x(i);
f(j) = f(j) + 1;
end;
... | Give a code snippet in #PL.2FI
Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Downward_for | Loops/Downward for | Task
Write a for loop which writes a countdown from 10 to 0.
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 loop body... | #Modula-3 | Modula-3 | FOR i := 10 TO 0 BY -1 DO
IO.PutInt(i);
END; | Give a code snippet in #Modula-3
Task
Write a for loop which writes a countdown from 10 to 0.
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/Inc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jaro_similarity | Jaro similarity | The Jaro distance is a measure of edit distance between two strings; its inverse, called the Jaro similarity, is a measure of two strings' similarity: the higher the value, the more similar the strings are. The score is normalized such that 0 equates to no similarities and 1 is an exact match.
Definition
The... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | ClearAll[JaroDistance]
JaroDistance[s_String, t_String] := Module[{slen, tlen, maxdistance, smatches, tmatches, matches, transpositions, start, end, k, schar, tchar},
slen = StringLength[s];
tlen = StringLength[t];
schar = Characters[s];
tchar = Characters[t];
If[slen == tlen == 0,
1
,
maxdistance = ... | Give a code snippet in #Mathematica_.2F_Wolfram_Language
The Jaro distance is a measure of edit distance between two strings; its inverse, called the Jaro similarity, is a measure of two strings' similarity: the higher the value, the more similar the strings are. The score is normalized such that 0 equates to no s... | 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... | #Excel | Excel | A1 : Kelvin
B1 : Celsius
C1 : Fahrenheit
D1 : Rankine
Name A2 : K
B2 : =K-273.15
C2 : =K*1.8-459.67
D2 : =K*1.8
Input in A1 | Give a code snippet in #Excel
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/Towers_of_Hanoi | Towers of Hanoi | Task
Solve the Towers of Hanoi problem with recursion.
| #.D0.9C.D0.9A-61.2F52 | МК-61/52 | ^ 2 x^y П0 <-> 2 / {x} x#0 16
3 П3 2 П2 БП 20 3 П2 2 П3
1 П1 ПП 25 КППB ПП 28 КППA ПП 31
КППB ПП 34 КППA ИП1 ИП3 КППC ИП1 ИП2 КППC
ИП3 ИП2 КППC ИП1 ИП3 КППC ИП2 ИП1 КППC ИП2
ИП3 КППC ИП1 ИП3 КППC В/О ИП1 ИП2 БП 62
ИП2 ИП1 КППC ИП1 ИП2 ИП3 П1 -> П3 ->
П2 В/О 1 0 / + С/П КИП0 ИП0 x=0
89 3 3 1 ИНВ ^ ВП 2 С/П В/О | Give a code snippet in #.D0.9C.D0.9A-61.2F52
Task
Solve the Towers of Hanoi problem with recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #Bracmat | Bracmat | ( ( strip
= string chars s pat
. !arg:(?string.?chars)
& :?s
&
' ( ?
( %
: [%( utf$!sjt
& ( @($chars:? !sjt ?)
| rev$!sjt !s:?s
)
& ~
)
... | Give a code snippet in #Bracmat
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in... | 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
... | #FALSE | FALSE | [0\$2=$[@~@@]?~[$$2>\1&&[\~\
3[\$@$@1+\$*>][\$@$@$@$@\/*=[%\~\$]?2+]#%
]?]?%]p: | Give a code snippet in #FALSE
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Logo | Logo | to dcr :step :length
make "step :step - 1
make "length :length / 1.41421
if :step > 0 [rt 45 dcr :step :length lt 90 dcl :step :length rt 45]
if :step = 0 [rt 45 fd :length lt 90 fd :length rt 45]
end
to dcl :step :length
make "step :step - 1
make "length :length / 1.41421
if :step > 0 [lt 45 dcr :step ... | Give a code snippet in #Logo
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Map_range | Map range | Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly mapped to a value
t
{\di... | #PowerShell | PowerShell |
function Group-Range
{
[CmdletBinding()]
[OutputType([PSCustomObject])]
Param
(
[Parameter(Mandatory=$true,
Position=0)]
[ValidateCount(2,2)]
[double[]]
$Range1,
[Parameter(Mandatory=$true,
Position=1)]
[ValidateCo... | Give a code snippet in #PowerShell
Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primality_by_Wilson%27s_theorem | Primality by Wilson's theorem | Task
Write a boolean function that tells whether a given integer is prime using Wilson's theorem.
By Wilson's theorem, a number p is prime if and only if p divides (p - 1)! + 1.
Remember that 1 and all non-positive integers are not prime.
See also
Cut-the-knot: Wilson's theorem.
Wikipedia: Wilson's theorem
| #Go | Go | package main
import (
"fmt"
"math/big"
)
var (
zero = big.NewInt(0)
one = big.NewInt(1)
prev = big.NewInt(factorial(20))
)
// Only usable for n <= 20.
func factorial(n int64) int64 {
res := int64(1)
for k := n; k > 1; k-- {
res *= k
}
return res
}
// If memo == true,... | Give a code snippet in #Go
Task
Write a boolean function that tells whether a given integer is prime using Wilson's theorem.
By Wilson's theorem, a number p is prime if and only if p divides (p - 1)! + 1.
Remember that 1 and all non-positive integers are not prime.
See also
Cut-the-knot: Wilson's theorem.
Wik... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Include_a_file | Include a file | Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| #Quackery | Quackery | $ "myfile.qky" loadfile | Give a code snippet in #Quackery
Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Kaprekar_numbers | Kaprekar numbers | A positive integer is a Kaprekar number if:
It is 1 (unity)
The decimal representation of its square may be split once into two parts consisting of positive integers which sum to the original number.
Note that a split resulting in a part consisting purely of 0s is not valid,
as 0 is not considered positive.
... | #Quackery | Quackery | [ dup 1 = if done
dup temp put
dup *
false swap 1
[ base share *
2dup /mod
over 0 = iff
2drop done
dup 0 = iff
2drop again
+ temp share = iff
[ rot not unrot ]
done
again ]
2drop
temp release ] is kaprekar ( n --> b )
say... | Give a code snippet in #Quackery
A positive integer is a Kaprekar number if:
It is 1 (unity)
The decimal representation of its square may be split once into two parts consisting of positive integers which sum to the original number.
Note that a split resulting in a part consisting purely of 0s is not valid,... | 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 |... | #jq | jq | "little" as $x
| "Mary had a \($x) lamb" | Give a code snippet in #jq
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
Con... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
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 |... | #Ceylon | Ceylon | shared void run() {
{Integer*} getFactors(Integer n) =>
(1..n).filter((Integer element) => element.divides(n));
for(Integer i in 1..100) {
print("the factors of ``i`` are ``getFactors(i)``");
}
} | Give a code snippet in #Ceylon
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/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... | #Kotlin | Kotlin | // version 1.0.6
fun main(args: Array<String>) {
while (true) println("SPAM")
} | Give a code snippet in #Kotlin
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
Loo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Soundex | Soundex | Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is a major issue in many of the ... | #COBOL | COBOL | **** sndxtest *********************************************
* Demonstrate the soundex encoding functions.
***************************************************************
Identification division.
Program-id. sndxtest.
Data division.
Working-storage section.
01 sampl... | Give a code snippet in #COBOL
Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_two-dimensional_array_at_runtime | Create a two-dimensional array at runtime |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ... | #Fermat | Fermat | ?m; {imput the dimensions of the array}
?n;
Array a[m,n]; {generate an array of m rows and n columns}
a[m\2, n\2] := m+n-1; {put some value in one of the cells}
!!a[m\2, n\2]; {display that entry}
@[a]; {delete the array} | Give a code snippet in #Fermat
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those num... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Interactive_programming_(repl) | Interactive programming (repl) | Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
Task
Show how to start this... | #OCaml | OCaml | $ ocaml
Objective Caml version 3.12.1
# let f s1 s2 sep = String.concat sep [s1; ""; s2];;
val f : string -> string -> string -> string = <fun>
# f "Rosetta" "Code" ":";;
- : string = "Rosetta::Code"
# | Give a code snippet in #OCaml
Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #Clean | Clean | import StdEnv
fileSize fileName world
# (ok, file, world) = fopen fileName FReadData world
| not ok = abort "Cannot open file"
# (ok, file) = fseek file 0 FSeekEnd
| not ok = abort "Cannot seek file"
# (size, file) = fposition file
(_, world) = fclose file world
= (size, world)
Start w... | Give a code snippet in #Clean
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Unbias_a_random_generator | Unbias a random generator |
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random number generator to create a function/method/sub... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Dim random As New Random()
Function RandN(n As Integer) As Boolean
Return random.Next(0, n) = 0
End Function
Function Unbiased(n As Integer) As Boolean
Dim flip1 As Boolean
Dim flip2 As Boolean
Do
flip1 = RandN(n)
flip2 = RandN... | Give a code snippet in #Visual_Basic_.NET
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random numbe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #PowerShell | PowerShell |
Enum fruits {
Apple
Banana
Cherry
}
[fruits]::Apple
[fruits]::Apple + 1
[fruits]::Banana + 1
| Give a code snippet in #PowerShell
Task
Create an enumeration of constants with and without explicit values.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Usage | Queue/Usage |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of queues, see the FIFO task.)
Ope... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols nobinary
-- Queue Usage Demonstration Program -------------------------------------------
method main(args = String[]) public constant
kew = RCQueueImpl()
do
say kew.pop()
catch ex = IndexOutOfBoundsException
say ex.getMessage
... | Give a code snippet in #NetRexx
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Create a queue data structure and demonstrate its operations.
(For implementations of q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #BASIC256 | BASIC256 | # Display first 22 values
print "The first 22 numbers generated by the sequence are : "
for i = 1 to 22
print nonSquare(i); " ";
next i
print
# Check for squares up to one million
found = false
for i = 1 to 1e6
j = sqrt(nonSquare(i))
if j = int(j) then
found = true
print i, " square number... | Give a code snippet in #BASIC256
Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A00... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #Java | Java | import java.util.Random;
public class NestedLoopTest {
public static final Random gen = new Random();
public static void main(String[] args) {
int[][] a = new int[10][10];
for (int i = 0; i < a.length; i++)
for (int j = 0; j < a[i].length; j++)
a[i][j] = gen.nextInt... | Give a code snippet in #Java
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #PowerShell | PowerShell |
function Reverse-String ([string]$String)
{
[char[]]$output = $String.ToCharArray()
[Array]::Reverse($output)
$output -join ""
}
[string]$url = "http://www.puzzlers.org/pub/wordlists/unixdict.txt"
[string]$out = ".\unixdict.txt"
(New-Object System.Net.WebClient).DownloadFile($url, $out)
[string[]]$f... | Give a code snippet in #PowerShell
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gaussian_elimination | Gaussian elimination | Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| #Go | Go | package main
import (
"errors"
"fmt"
"log"
"math"
)
type testCase struct {
a [][]float64
b []float64
x []float64
}
var tc = testCase{
// common RC example. Result x computed with rational arithmetic then
// converted to float64, and so should be about as close to correct as
... | Give a code snippet in #Go
Task
Solve Ax=b using Gaussian elimination then backwards substitution.
A being an n by n matrix.
Also, x and b are n by 1 vectors.
To improve accuracy, please use partial pivoting and scaling.
See also
the Wikipedia entry: Gaussian elimination
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Read_a_PPM_file | Bitmap/Read a PPM file | Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to grayscale one.
| #Lua | Lua | function Read_PPM( filename )
local fp = io.open( filename, "rb" )
if fp == nil then return nil end
local data = fp:read( "*line" )
if data ~= "P6" then return nil end
repeat
data = fp:read( "*line" )
until string.find( data, "#" ) == nil
local image = {}
local size_x, ... | Give a code snippet in #Lua
Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to grayscal... | 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.
| #Raku | Raku | unlink 'input.txt';
unlink '/input.txt';
rmdir 'docs';
rmdir '/docs'; | Give a code snippet in #Raku
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/Array_concatenation | Array concatenation | Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program concAreaString.s */
/*******************************************/
/* Constantes file */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstante... | Give a code snippet in #AArch64_Assembly
Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_characters | Special characters | Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to be used as a normal charact... | #jq | jq | ^[a-zA-Z_][a-zA-Z_0-9]*$ | Give a code snippet in #jq
Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to... | 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,... | #PL.2FI | PL/I | /* Example of an array having fixed dimensions */
declare A(10) float initial (1, 9, 4, 6, 7, 2, 5, 8, 3, 10);
A(6) = -45;
/* Example of an array having dynamic bounds. */
get list (N);
begin;
declare B(N) float initial (9, 4, 7, 3, 8, 11, 0, 5, 15, 6);
B(3) = -11;
put (B(2));
end;
/* Example of a dyna... | Give a code snippet in #PL.2FI
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 retr... | 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.
... | #Processing | Processing | size( 105,120 );
for ( int i=20; i<=100; i+=20 )
for ( int j=10; j<=i; j+=20 )
text( "*", j,i ); | Give a code snippet in #Processing
“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 st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_a_system_command | Execute a system command | Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| #DCL | DCL | Directory | Give a code snippet in #DCL
Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| christopher/rosetta-code | |
http://rosettacode.org/wiki/JSON | JSON | Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| #8th | 8th | [1,2,3] . cr
| Give a code snippet in #8th
Load a JSON string into a data structure.
Also, create a new data structure and serialize it into JSON.
Use objects and arrays (as appropriate for your language)
and make sure your JSON is valid (https://jsonformatter.org).
| 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... | #Ada | Ada | with Ada.Numerics.Elementary_Functions;
with Ada.Directories; use Ada.Directories;
with Ada.Strings.Fixed; use Ada.Strings;
with Ada.Command_Line; use Ada.Command_Line;
with Ada.Text_IO; use Ada.Text_IO;
with Dir_Iterators.Recursive;
procedure File_Size_Distribution is
type Exponent_Type is range ... | Give a code snippet in #Ada
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 f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #Groovy | Groovy | /** The following closure creates a list of n evenly-spaced points around the unit circle,
* useful in FFT calculations, among other things */
def rootsOfUnity = { n ->
(0..<n).collect {
Complex.fromPolar(1, 2 * Math.PI * it / n)
}
} | Give a code snippet in #Groovy
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Minimum_multiple_of_m_where_digital_sum_equals_m | Minimum multiple of m where digital sum equals m | Generate the sequence a(n) when each element is the minimum integer multiple m such that the digit sum of n times m is equal to n.
Task
Find the first 40 elements of the sequence.
Stretch
Find the next 30 elements of the sequence.
See also
OEIS:A131382 - Minimal number m such that Sum_digits(n*m)=n
| #XPL0 | XPL0 | func SumDigits(N); \Return sum of digits in N
int N, S;
[S:= 0;
while N do
[N:= N/10;
S:= S + rem(0);
];
return S;
];
int C, N, M;
[C:= 0; N:= 1;
repeat M:= 1;
while SumDigits(N*M) # N do M:= M+1;
IntOut(0, M);
C:= C+1;
if rem (C/10) then ChOut(0, 9\tab\) else CrLf(... | Give a code snippet in #XPL0
Generate the sequence a(n) when each element is the minimum integer multiple m such that the digit sum of n times m is equal to n.
Task
Find the first 40 elements of the sequence.
Stretch
Find the next 30 elements of the sequence.
See also
OEIS:A131382 - Minimal number m such tha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Rust | Rust | use std::net::ToSocketAddrs;
fn main() {
let host = "www.kame.net";
// Ideally, we would want to use std::net::lookup_host to resolve the host ips,
// but at time of writing this, it is still unstable. Fortunately, we can
// still resolve using the ToSocketAddrs trait, but we need to add a port,
/... | Give a code snippet in #Rust
DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Infinity | Infinity | Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise, return the largest possible po... | #Icon_and_Unicon | Icon and Unicon | print, !Values.f_infinity ;; for normal floats or
print, !Values.D_infinity ;; for doubles | Give a code snippet in #Icon_and_Unicon
Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CSV_data_manipulation | CSV data manipulation | CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, change some values and save the cha... | #REXX | REXX | /* REXX ***************************************************************
* extend in.csv to add a column containing the sum of the lines' elems
* 21.06.2013 Walter Pachl
**********************************************************************/
csv='in.csv'
Do i=1 By 1 While lines(csv)>0
l=linein(csv)
If i=1 Then
l... | Give a code snippet in #REXX
CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, chang... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rhonda_numbers | Rhonda numbers | A positive integer n is said to be a Rhonda number to base b if the product of the base b digits of n is equal to b times the sum of n's prime factors.
These numbers were named by Kevin Brown after an acquaintance of his whose residence number was 25662, a member of the base 10 numbers with this property.
25662 is ... | #Factor | Factor | USING: formatting grouping io kernel lists lists.lazy math
math.parser math.primes math.primes.factors prettyprint ranges
sequences sequences.extras ;
: rhonda? ( n base -- ? )
[ [ >base 1 group ] keep '[ _ base> ] map-product ]
[ swap factors sum * ] 2bi = ;
: rhonda ( base -- list ) 1 lfrom swap '[ _ rhon... | Give a code snippet in #Factor
A positive integer n is said to be a Rhonda number to base b if the product of the base b digits of n is equal to b times the sum of n's prime factors.
These numbers were named by Kevin Brown after an acquaintance of his whose residence number was 25662, a member of the base 10 numbers... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dutch_national_flag_problem | Dutch national flag problem |
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the colours in the Dutch national fla... | #Ruby | Ruby | class Ball
FLAG = {red: 1, white: 2, blue: 3}
def initialize
@color = FLAG.keys.sample
end
def color
@color
end
def <=>(other) # needed for sort, results in -1 for <, 0 for == and 1 for >.
FLAG[self.color] <=> FLAG[other.color]
end
def inspect
@color
end
end
balls = []
ball... | Give a code snippet in #Ruby
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the col... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_frequency | Function frequency | Display - for a program or runtime environment (whatever suits the style of your language) - the top ten most frequently occurring functions (or also identifiers or tokens, if preferred).
This is a static analysis: The question is not how often each function is
actually executed at runtime, but how often it is used by... | #BBC_BASIC | BBC BASIC | INSTALL @lib$+"SORTLIB"
Sort% = FN_sortinit(1,0) : REM Descending
Valid$ = "0123456789@ABCDEFGHIJKLMNOPQRSTUVWXYZ_`abcdefghijklmnopqrstuvwxyz"
DIM func$(1000), cnt%(1000)
nFunc% = 0
file% = OPENIN("*.bbc")
WHILE NOT EOF#file%
ll% = BGET#file%
no% = BGET#file... | Give a code snippet in #BBC_BASIC
Display - for a program or runtime environment (whatever suits the style of your language) - the top ten most frequently occurring functions (or also identifiers or tokens, if preferred).
This is a static analysis: The question is not how often each function is
actually executed at r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions/Catch_an_exception_thrown_in_a_nested_call | Exceptions/Catch an exception thrown in a nested call | Show how to create a user-defined exception and show how to catch an exception raised from several nested calls away.
Create two user-defined exceptions, U0 and U1.
Have function foo call function bar twice.
Have function bar call function baz.
Arrange for function baz to rais... | #MATLAB_.2F_Octave | MATLAB / Octave | function exceptionsCatchNestedCall()
function foo()
try
bar(1);
bar(2);
catch
disp(lasterror);
rethrow(lasterror);
end
end
function bar(i)
baz(i);
end
function baz(i)
switch i
case 1
... | Give a code snippet in #MATLAB_.2F_Octave
Show how to create a user-defined exception and show how to catch an exception raised from several nested calls away.
Create two user-defined exceptions, U0 and U1.
Have function foo call function bar twice.
Have function bar call function ba... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Musical_scale | Musical scale | Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, Fa, Sol, La, Si/Ti, Do(1 octa... | #Tcl | Tcl | package require sound
# Encapsulate the tone generation
set filter [snack::filter generator 1 20000 0.5 sine -1]
set sound [snack::sound -rate 22050]
proc play {frequency length} {
global filter sound
$filter configure $frequency
$sound play -filter $filter
# Need to run event loop; Snack uses it... | Give a code snippet in #Tcl
Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, ... | 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) ... | #Nim | Nim |
from random import random, randomize, shuffle
from strutils import repeat
randomize()
proc gen(n: int): string =
result = "[]".repeat(n)
shuffle(result)
proc balanced(txt: string): bool =
var b = 0
for c in txt:
case c
of '[':
inc(b)
of ']':
dec(b)
if b < 0: return false
... | Give a code snippet in #Nim
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-nes... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's stat... | #R | R | Y <- function(f) {
(function(x) { (x)(x) })( function(y) { f( (function(a) {y(y)})(a) ) } )
} | Give a code snippet in #R
In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primes_-_allocate_descendants_to_their_ancestors | Primes - allocate descendants to their ancestors | The concept, is to add the decomposition into prime factors of a number to get its 'ancestors'.
The objective is to demonstrate that the choice of the algorithm can be crucial in term of performance.
This solution could be compared to the solution that would use the decomposition into primes for all the numbers betw... | #Racket | Racket | #lang racket
(define-syntax-rule (define/mem (name args ...) body ...)
(begin
(define cache (make-hash))
(define (name args ...)
(hash-ref! cache (list args ...) (lambda () body ...)))))
(define (take-last x n)
(drop x (- (length x) n)))
(define (borders x)
(if (> (length x) 5)
(append (ta... | Give a code snippet in #Racket
The concept, is to add the decomposition into prime factors of a number to get its 'ancestors'.
The objective is to demonstrate that the choice of the algorithm can be crucial in term of performance.
This solution could be compared to the solution that would use the decomposition into... | christopher/rosetta-code | |
http://rosettacode.org/wiki/N-queens_problem | N-queens problem |
Solve the eight queens puzzle.
You can extend the problem to solve the puzzle with a board of size NxN.
For the number of solutions for small values of N, see OEIS: A000170.
Related tasks
A* search algorithm
Solve a Hidato puzzle
Solve a Holy Knight's tour
Knight's tour
Peaceful chess queen armie... | #ABAP | ABAP |
TYPES: BEGIN OF gty_matrix,
1 TYPE c,
2 TYPE c,
3 TYPE c,
4 TYPE c,
5 TYPE c,
6 TYPE c,
7 TYPE c,
8 TYPE c,
9 TYPE c,
10 TYPE c,
END OF gty_matrix,
gty_t_matrix TYPE STANDARD TABLE OF gty_matrix INITIAL SI... | Give a code snippet in #ABAP
Solve the eight queens puzzle.
You can extend the problem to solve the puzzle with a board of size NxN.
For the number of solutions for small values of N, see OEIS: A000170.
Related tasks
A* search algorithm
Solve a Hidato puzzle
Solve a Holy Knight's tour
Knight's to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #PowerShell | PowerShell | $DNS = Resolve-DnsName -Name www.kame.net
Write-Host "IPv4:" $DNS.IP4Address "`nIPv6:" $DNS.IP6Address | Give a code snippet in #PowerShell
DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation | Horner's rule for polynomial evaluation | A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\displaystyle ((((0)x+6)x+(-4))x... | #Prolog | Prolog | horner([], _X, 0).
horner([H|T], X, V) :-
horner(T, X, V1),
V is V1 * X + H.
| Give a code snippet in #Prolog
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
)
{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compound_data_type | Compound data type |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
Related task
Enumeration
S... | #Ursala | Ursala | point :: x y | Give a code snippet in #Ursala
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Task
Create a compound data type:
Point(x,y)
A compound data type is one that holds multiple independent values.
... | 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, ... | #S-lang | S-lang | print(0^0); | Give a code snippet in #S-lang
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_proper_divisor_of_n | Largest proper divisor of n | Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| #Yabasic | Yabasic | print "El mayor divisor propio de n es:\n"
print " 1 1 ";
for i = 3 to 100
for j = i-1 to 1 step -1
If mod(i, j) = 0 then print j using "##"; : break : fi
next j
if mod(i, 10) = 0 then print : fi
next i
print
end | Give a code snippet in #Yabasic
Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_pentagon | Sierpinski pentagon | Produce a graphical or ASCII-art representation of a Sierpinski pentagon (aka a Pentaflake) of order 5. Your code should also be able to correctly generate representations of lower orders: 1 to 4.
See also
Sierpinski pentagon
| #Racket | Racket | #lang racket/base
(require racket/draw pict racket/math racket/class)
;; exterior angle
(define 72-degrees (degrees->radians 72))
;; After scaling we'll have 2 sides plus a gap occupying the length
;; of a side before scaling. The gap is the base of an isosceles triangle
;; with a base angle of 72 degrees.
(define s... | Give a code snippet in #Racket
Produce a graphical or ASCII-art representation of a Sierpinski pentagon (aka a Pentaflake) of order 5. Your code should also be able to correctly generate representations of lower orders: 1 to 4.
See also
Sierpinski pentagon
| 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 ... | #XPL0 | XPL0 | include c:\cxpl\stdlib;
char Dict(10,10);
int Entries;
proc AddEntry(Letter, Greek); \Insert entry into associative array
char Letter, Greek;
[Dict(Entries,0):= Letter;
StrCopy(Greek, @Dict(Entries,1));
Entries:= Entries+1; \(limit checks ignored for simplicity)
];
int I;
[Entries:= 0;
AddEntry(^A, "a... | Give a code snippet in #XPL0
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/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Arturo | Arturo | num: 2
if? num=2 [
print "yep, num is 2"
]
else [
print "something went wrong..."
] | Give a code snippet in #Arturo
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bead_sort | Sorting algorithms/Bead 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
... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: beadSort (inout array integer: a) is func
local
var integer: max is 0;
var integer: sum is 0;
var array bitset: beads is 0 times {};
var integer: i is 0;
var integer: j is 0;
begin
beads := length(a) times {};
for i range 1 to length(a) do
if... | Give a code snippet in #Seed7
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/Ulam_spiral_(for_primes) | Ulam spiral (for primes) | An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is shown with sequential integers, ... | #Raku | Raku | sub MAIN($max = 160, $start = 1) {
(my %world){0}{0} = 0;
my $loc = 0+0i;
my $dir = 1;
my $n = $start;
my $side = 0;
while ++$side < $max {
step for ^$side;
turn-left;
step for ^$side;
turn-left;
}
braille-graphics %world;
sub step {
$loc += $dir;
%world{$loc.im}{$loc.re}... | Give a code snippet in #Raku
An Ulam spiral (of primes) is a method of visualizing primes when expressed in a (normally counter-clockwise) outward spiral (usually starting at 1), constructed on a square grid, starting at the "center".
An Ulam spiral is also known as a prime spiral.
The first grid (green) is show... | christopher/rosetta-code | |
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retr... | #IDL | IDL | print,systime(0)
Wed Feb 10 09:41:14 2010
print,systime(1)
1.2658237e+009
| Give a code snippet in #IDL
Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Da... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_two-dimensional_array_at_runtime | Create a two-dimensional array at runtime |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ... | #Julia | Julia | function input(prompt::AbstractString)
print(prompt)
return readline()
end
n = input("Upper bound for dimension 1: ") |>
x -> parse(Int, x)
m = input("Upper bound for dimension 2: ") |>
x -> parse(Int, x)
x = rand(n, m)
display(x)
x[3, 3] # overloads `getindex` generic function
x[3, 3] = 5.0... | Give a code snippet in #Julia
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numb... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const func bitset: castOut (in integer: base, in integer: start, in integer: ending) is func
result
var bitset: casted is {};
local
var bitset: ran is {};
var integer: x is 0;
var integer: n is 0;
var integer: k is 0;
var boolean: finished is FALSE;
begin
fo... | Give a code snippet in #Seed7
Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or othe... | christopher/rosetta-code |
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