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/Langton%27s_ant | Langton's ant | Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the following rules:
If the ce... | #Phix | Phix | sequence grid = repeat(repeat(' ',100),100)
integer aX = 50, aY = 50,
gXY, angle = 1 -- ' '/'#'; 0,1,2,3 = NESW
constant dX = {0,-1,0,1} -- (dY = reverse(dX))
while aX>=1 and aX<=100
and aY>=1 and aY<=100 do
gXY = grid[aX][aY]
grid[aX][aY] = 67-gXY ... | Give a code snippet in #Phix
Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_whitespace_from_a_string/Top_and_tail | Strip whitespace from a string/Top and tail | Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace removed
For the purposes of thi... | #Forth | Forth | : -leading ( addr len -- addr' len' ) \ called "minus-leading"
begin
over c@ bl = \ fetch character at addr, test if blank (space)
while
\ cut 1 leading character by incrementing address & decrementing length
1 /string \ "cut-string"
repeat ; | Give a code snippet in #Forth
Task
Demonstrate how to strip leading and trailing whitespace from a string.
The solution should demonstrate how to achieve the following three results:
String with leading whitespace removed
String with trailing whitespace removed
String with both leading and trailing whitespace re... | 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... | #Aime | Aime | length("Hello, World!") | Give a code snippet in #Aime
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 conta... | 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
| #Objective-C | Objective-C | type bool = false | true | Give a code snippet in #Objective-C
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/Probabilistic_choice | Probabilistic choice | Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because floating point arithmetic is invol... | #Phix | Phix | with javascript_semantics
constant lim = 1000000,
{names, probs} = columnize({{"aleph", 1/5},
{"beth", 1/6},
{"gimel", 1/7},
{"daleth", 1/8},
{"he", 1/9},
{"waw", ... | Give a code snippet in #Phix
Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because floa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #AArch64_Assembly | AArch64 Assembly |
/* ARM assembly AARCH64 Raspberry PI 3B */
/* program zumkellex641.s */
/* REMARK 1 : this program use routines in a include file
see task Include a file language arm assembly
for the routine affichageMess conversion10
see at end of this program the instruction include */
/* REMARK 2 : this program... | Give a code snippet in #AArch64_Assembly
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on ho... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_in_octal | Count in octal | Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reached.
Related task
Integer sequ... | #AutoHotkey | AutoHotkey | DllCall("AllocConsole")
Octal(int){
While int
out := Mod(int, 8) . out, int := int//8
return out
}
Loop
{
FileAppend, % Octal(A_Index) "`n", CONOUT$
Sleep 200
} | Give a code snippet in #AutoHotkey
Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reach... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #Haxe | Haxe | using StringTools;
class Main {
static function main() {
var data = haxe.io.Bytes.ofString("The quick brown fox jumps over the lazy dog");
var crc = haxe.crypto.Crc32.make(data);
Sys.println(crc.hex());
}
} | Give a code snippet in #Haxe
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pythagorean_triples | Pythagorean triples | A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\displaystyle a,b,c}
are co-prime,... | #REXX | REXX | /*REXX program counts the number of Pythagorean triples that exist given a maximum */
/*──────────────────── perimeter of N, and also counts how many of them are primitives.*/
parse arg N . /*obtain optional argument from the CL.*/
if N=='' | N=="," then N= 100 ... | Give a code snippet in #REXX
A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\displ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number | Guess the number | Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issue a "Well guessed!" message, a... | #Batch_File | Batch File | @echo off
set /a answer=%random%%%(10-1+1)+1
set /p guess=Pick a number between 1 and 10:
:loop
if %guess%==%answer% (echo Well guessed!
pause) else (set /p guess=Nope, guess again:
goto loop) | Give a code snippet in #Batch_File
Task
Write a program where the program chooses a number between 1 and 10.
A player is then prompted to enter a guess. If the player guesses wrong, then the prompt appears again until the guess is correct.
When the player has made a successful guess the computer will issu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #min | min | "Hello,How,Are,You,Today" "," split "." join print | Give a code snippet in #min
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks rela... | 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... | #Zig | Zig |
const std = @import("std");
const stdout = std.io.getStdOut().outStream();
var board = [_]i8{-1} ** 8;
inline fn abs(x: var) @TypeOf(x) {
return if (x < 0) -x else x;
}
fn safe(c: i32, r: i32) bool {
var i: i32 = 0;
return while (i < c) : (i += 1) {
const q = board[@intCast(u3, i)];
... | Give a code snippet in #Zig
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 tou... | 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
... | #Qi | Qi | (define prime?-0
K N -> true where (> (* K K) N)
K N -> false where (= 0 (MOD N K))
K N -> (prime?-0 (+ K 2) N))
(define prime?
1 -> false
2 -> true
N -> false where (= 0 (MOD N 2))
N -> (prime?-0 3 N)) | Give a code snippet in #Qi
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 ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/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 |... | #Nim | Nim | import parseopt, strutils
var
opt: OptParser = initOptParser()
str = opt.cmdLineRest.split
a: int = 0
b: int = 0
try:
a = parseInt(str[0])
b = parseInt(str[1])
except ValueError:
quit("Invalid params. Two integers are expected.")
echo("a : " & $a)
echo("b : " & $b)
echo("a + b : " & $(... | 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/Remove_duplicate_elements | Remove duplicate elements |
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
... | #Modula-2 | Modula-2 |
MODULE RemoveDuplicates;
FROM STextIO IMPORT
WriteLn;
FROM SWholeIO IMPORT
WriteInt;
TYPE
TArrayRange = [1 .. 7];
TArray = ARRAY TArrayRange OF INTEGER;
VAR
DataArray, ResultArray: TArray;
ResultIndex, LastResultIndex, Position: CARDINAL;
IsNewNumber: BOOLEAN;
BEGIN
(* Set the data. *);
Data... | Give a code snippet in #Modula-2
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/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #Elixir | Elixir | defmodule MontyHall do
def simulate(n) do
{stay, switch} = simulate(n, 0, 0)
:io.format "Staying wins ~w times (~.3f%)~n", [stay, 100 * stay / n]
:io.format "Switching wins ~w times (~.3f%)~n", [switch, 100 * switch / n]
end
defp simulate(0, stay, switch), do: {stay, switch}
defp simulate... | Give a code snippet in #Elixir
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Idiomatically_determine_all_the_characters_that_can_be_used_for_symbols | Idiomatically determine all the characters that can be used for symbols | Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a computer programmer can choose to name, ... | #J | J | a.#~1=#@;: ::0:"1 'b',.a.,.'c'
0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz | Give a code snippet in #J
Idiomatically determine all the characters that can be used for symbols.
The word symbols is meant things like names of variables, procedures (i.e., named fragments of programs, functions, subroutines, routines), statement labels, events or conditions, and in general, anything a computer prog... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #ooRexx | ooRexx | v=''
w=' '
if v=='' Then Say 'v contains the empty string'<
If length(w)>0 Then Say 'Variable w does not contain the empty string'
If w='' Then Say 'this is not a good test' | Give a code snippet in #ooRexx
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Ot... | 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... | #BBC_BASIC | BBC BASIC | PRINT FNsum(j, 1, 100, FNreciprocal)
END
DEF FNsum(RETURN i, lo, hi, RETURN func)
LOCAL temp
FOR i = lo TO hi
temp += FN(^func)
NEXT
= temp
DEF FNreciprocal = 1/i | Give a code snippet in #BBC_BASIC
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_two_numerical_lists | Order two numerical lists | sorting
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
She... | #Racket | Racket | #lang racket
(define (lex<? a b)
(cond ((null? b) #f)
((null? a) #t)
((= (car a) (car b)) (lex<? (cdr a) (cdr b)))
(else (< (car a) (car b)))))
(lex<? '(1 2 3 4 5) '(1 2 3 4 4)) ; -> #f
| Give a code snippet in #Racket
sorting
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 |... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #F.23 | F# |
// A program that will run in the interpreter (fsi.exe)
printf "Goodbye, World!";;
// A compiled program
[<EntryPoint>]
let main args =
printf "Goodbye, World!"
0
| Give a code snippet in #F.23
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Miller%E2%80%93Rabin_primality_test | Miller–Rabin primality test |
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. 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 Miller–Rabin primality test or Rabin–Miller prima... | #OCaml | OCaml |
(* Translated from the wikipedia pseudo-code *)
let miller_rabin n ~iter:k =
(* return r and d where n = 2^r*d (from scheme implementation) *)
let get_rd n =
let rec loop r d =
(* not even *)
if Z.(equal (logand d one) one) then
(r,d)
else
loop Z.(r + one) Z.(div d ~$2)
i... | Give a code snippet in #OCaml
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. 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 Miller–Rabin prima... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_language_name_in_3D_ASCII | Write language name in 3D ASCII | Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| #Nanoquery | Nanoquery | println " ________ ________ ________ ________ ________ ___ ___ _______ ________ ___ ___ "
println "|\\ ___ \\|\\ __ \\|\\ ___ \\|\\ __ \\|\\ __ \\|\\ \\|\\ \\|\\ ___ \\ |\\ __ \\ |\\ \\ / /| "
println "\\ \\ \\\\ \\ \\ \\ \\|\\ \\ \\ \\\\ \\ \\ \\ \\|\\ \\ \\... | Give a code snippet in #Nanoquery
Task
Write/display a language's name in 3D ASCII.
(We can leave the definition of "3D ASCII" fuzzy,
so long as the result is interesting or amusing,
not a cheap hack to satisfy the task.)
Related tasks
draw a sphere
draw a cuboid
draw a rotating cube
draw a Deathstar
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Traversal | Singly-linked list/Traversal | Traverse from the beginning of a singly-linked list to the end.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked ... | #SSEM | SSEM | 11101000000000100000000000000000 0. -23 to c
10011000000000010000000000000000 1. Sub. 25
10010000000001100000000000000000 2. c to 9
10101000000000010000000000000000 3. Sub. 21
11010000000001100000000000000000 4. c to 11
10010000000000100000000000000000 5. -9 to c
10010000000001100000000000000000 6. c to 9... | Give a code snippet in #SSEM
Traverse from the beginning of a singly-linked list to the end.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definiti... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Befunge | Befunge | ~:"z"`#v_:"m"`#v_:"`"` |>
:"Z"`#v_:"M"`#v_:"@"`|>
: 0 `#v_@v-6-7< >
, < <+6+7 <<v | Give a code snippet in #Befunge
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #E | E | def makeNounExpr := <elang:evm.makeNounExpr>
def dynVarName(name) {
def variable := makeNounExpr(null, name, null)
return e`{
def a := 1
def b := 2
def c := 3
{
def $variable := "BOO!"
[a, b, c]
}
}`.eval(safeScope)
}
? dynVarName("... | Give a code snippet in #E
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Gauss-Jordan_matrix_inversion | Gauss-Jordan matrix inversion | Task
Invert matrix A using Gauss-Jordan method.
A being an n × n matrix.
| #J | J | require 'math/misc/linear'
augmentR_I1=: ,. e.@i.@# NB. augment matrix on the right with its Identity matrix
matrix_invGJ=: # }."1 [: gauss_jordan@augmentR_I1 | Give a code snippet in #J
Task
Invert matrix A using Gauss-Jordan method.
A being an n × n matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #COBOL | COBOL | IDENTIFICATION DIVISION.
PROGRAM-ID. string-case-85.
DATA DIVISION.
WORKING-STORAGE SECTION.
01 example PIC X(9) VALUE "alphaBETA".
01 result PIC X(9).
PROCEDURE DIVISION.
DISPLAY "Example: " example
*> Using the intrinsic functions.
... | Give a code snippet in #COBOL
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #S-BASIC | S-BASIC |
comment
Return the rot13 transformation of s, preserving case and
passing non-alphabetic characters without change
end
function rot13(s = string) = string
var i, k = integer
var ch = char
var normal, rotated = string
normal = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
rotated = "NOPQRSTUV... | Give a code snippet in #S-BASIC
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abelian_sandpile_model/Identity | Abelian sandpile model/Identity | Our sandpiles are based on a 3 by 3 rectangular grid giving nine areas that
contain a number from 0 to 3 inclusive. (The numbers are said to represent
grains of sand in each area of the sandpile).
E.g. s1 =
1 2 0
2 1 1
0 1 3
and s2 =
2 1 3
1 0 1
0 1 0
Addition on sandpiles is done by a... | #Ruby | Ruby | class Sandpile
def initialize(ar) = @grid = ar
def to_a = @grid.dup
def + (other)
res = self.to_a.zip(other.to_a).map{|row1, row2| row1.zip(row2).map(&:sum) }
Sandpile.new(res)
end
def stable? = @grid.flatten.none?{|v| v > 3}
def avalanche
topple until stable?
self
end
def =... | Give a code snippet in #Ruby
Our sandpiles are based on a 3 by 3 rectangular grid giving nine areas that
contain a number from 0 to 3 inclusive. (The numbers are said to represent
grains of sand in each area of the sandpile).
E.g. s1 =
1 2 0
2 1 1
0 1 3
and s2 =
2 1 3
1 0 1
0 1 0
Addi... | 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 ... | #Tcl | Tcl |
puts "Enter width:"
set width [gets stdin]
puts "Enter height:"
set height [gets stdin]
# Initialize array
for {set i 0} {$i < $width} {incr i} {
for {set j 0} {$j < $height} {incr j} {
set arr($i,$j) ""
}
}
# Store value
set arr(0,0) "abc"
# Print value
puts "Element (0/0): $arr(0,0)"
# Cleanup array
unset arr
| Give a code snippet in #Tcl
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 number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Text | Hello world/Text | Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
| #GB_BASIC | GB BASIC | 10 print "Hello world!" | Give a code snippet in #GB_BASIC
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard erro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #Ruby | Ruby | str = "asdf"
reversed = str.reverse | Give a code snippet in #Ruby
Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty ... | 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... | #Sidef | Sidef | # Read
var csvfile = %f'data.csv';
var fh = csvfile.open_r;
var header = fh.line.trim_end.split(',');
var csv = fh.lines.map { .trim_end.split(',').map{.to_num} };
fh.close;
# Write
var out = csvfile.open_w;
out.say([header..., 'SUM'].join(','));
csv.each { |row| out.say([row..., row.sum].join(',')) };
out.close; | Give a code snippet in #Sidef
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, chan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded c... | #C.2B.2B | C++ |
#include <string>
#include <regex>
#include <algorithm>
#include <numeric>
#include <sstream>
bool CheckFormat(const std::string& isin)
{
std::regex isinRegEpx(R"([A-Z]{2}[A-Z0-9]{9}[0-9])");
std::smatch match;
return std::regex_match(isin, match, isinRegEpx);
}
std::string CodeISIN(const std::string& isin)
... | Give a code snippet in #C.2B.2B
An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the corre... | 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 ... | #K | K | {:[x<3;1;_f[x-1]+_f[x-2]]} | Give a code snippet in #K
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 gen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Josephus_problem | Josephus problem | Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner
0
{\displaystyle 0}
,
removing eve... | #Eiffel | Eiffel |
class
APPLICATION
create
make
feature
make
do
io.put_string ("Survivor is prisoner: " + execute (12, 4).out)
end
execute (n, k: INTEGER): INTEGER
-- Survivor of 'n' prisoners, when every 'k'th is executed.
require
n_positive: n > 0
k_positive: k > 0
n_larger: n > k
local
killidx:... | Give a code snippet in #Eiffel
Josephus problem is a math puzzle with a grim description:
n
{\displaystyle n}
prisoners are standing on a circle, sequentially numbered from
0
{\displaystyle 0}
to
n
−
1
{\displaystyle n-1}
.
An executioner walks along the circle, starting from prisoner
0
{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Additive_primes | Additive primes | Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry: A046704 additive primes.
... | #CLU | CLU | % Sieve of Erastothenes
% Returns an array [1..max] marking the primes
sieve = proc (max: int) returns (array[bool])
prime: array[bool] := array[bool]$fill(1, max, true)
prime[1] := false
for p: int in int$from_to(2, max/2) do
if prime[p] then
for comp: int in int$from_to_by(p*2, max,... | Give a code snippet in #CLU
Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry: ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #XPL0 | XPL0 | code ChOut=8, CrLf=9, IntOut=11;
ffunc M; \forward-referenced function declaration
func F(N);
int N;
return if N=0 then 1 else N - M(F(N-1));
func M(N);
int N;
return if N=0 then 0 else N - F(M(N-1));
int I;
[for I:= 0 to 19 do [IntOut(0, F(I)); ChOut(0, ^ )];
CrLf(0);
for I:= 0 to 19 do [IntOut(0, M(I)); ... | Give a code snippet in #XPL0
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)... | 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 ... | #Lasso | Lasso | local(haystack) = array('Zig', 'Zag', 'Wally', 'Ronald', 'Bush', 'Krusty', 'Charlie', 'Bush', 'Bozo')
#haystack->findindex('Bush')->first // 5
#haystack->findindex('Bush')->last // 8
protect => {^
handle_error => {^ error_msg ^}
fail_if(not #haystack->findindex('Washington')->first,'Washington is not in... | Give a code snippet in #Lasso
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 th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hilbert_curve | Hilbert curve |
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| #Ring | Ring |
# Project : Hilbert curve
load "guilib.ring"
paint = null
x1 = 0
y1 = 0
new qapp
{
win1 = new qwidget() {
setwindowtitle("Hilbert curve")
setgeometry(100,100,400,500)
label1 = new qlabel(win1) {
setgeometry(10,1... | Give a code snippet in #Ring
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/UTF-8_encode_and_decode | UTF-8 encode and decode | As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes representing that character in the... | #Action.21 | Action! | TYPE Unicode=[BYTE bc1,bc2,bc3]
BYTE ARRAY hex=['0 '1 '2 '3 '4 '5 '6 '7 '8 '9 'A 'B 'C 'D 'E 'F]
BYTE FUNC DecodeHex(CHAR c)
BYTE i
FOR i=0 TO 15
DO
IF c=hex(i) THEN
RETURN (i)
FI
OD
Break()
RETURN (255)
BYTE FUNC DecodeHex2(CHAR c1,c2)
BYTE h1,h2,res
h1=DecodeHex(c1)
h2=DecodeHex(... | Give a code snippet in #Action.21
As described in UTF-8 and in Wikipedia, UTF-8 is a popular encoding of (multi-byte) Unicode code-points into eight-bit octets.
The goal of this task is to write a encoder that takes a unicode code-point (an integer representing a unicode character) and returns a sequence of 1-4 bytes... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Periodic_table | Periodic table | Task
Display the row and column in the periodic table of the given atomic number.
The periodic table
Let us consider the following periodic table representation.
__________________________________________________________________________
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 1... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | ClearAll[FindPeriodGroup]
FindPeriodGroup[n_Integer] := Which[57 <= n <= 70,
{8, n - 53}
,
89 <= n <= 102,
{9, n - 85}
,
1 <= n <= 118,
{ElementData[n, "Period"], ElementData[n, "Group"]}
,
True,
Missing["Element does not exist"]
]
Row[{"Element ", #, " -> ", FindPeriodGroup[#]}] & /@ {1, 2, 29, 42,... | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Display the row and column in the periodic table of the given atomic number.
The periodic table
Let us consider the following periodic table representation.
__________________________________________________________________________
| 1 2 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hough_transform | Hough transform | Task
Implement the Hough transform, which is used as part of feature extraction with digital images.
It is a tool that makes it far easier to identify straight lines in the source image, whatever their orientation.
The transform maps each point in the target image,
(
ρ
,
θ
)
{\displaystyle (\rho ,\theta )}
, ... | #BBC_BASIC | BBC BASIC | Width% = 320
Height% = 240
VDU 23,22,Width%;Height%;8,16,16,128
*DISPLAY Pentagon.bmp
OFF
DIM hist%(Width%-1, Height%-1)
rs = 2 * SQR(Width%^2 + Height%^2) / Height% : REM Radial step
ts = PI / Width% : REM Angular step
h% = Height% / 2
REM Hough trans... | Give a code snippet in #BBC_BASIC
Task
Implement the Hough transform, which is used as part of feature extraction with digital images.
It is a tool that makes it far easier to identify straight lines in the source image, whatever their orientation.
The transform maps each point in the target image,
(
ρ
,
θ
)
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiplicative_order | Multiplicative order | The multiplicative order of a relative to m is the least positive integer n such that a^n is 1 (modulo m).
Example
The multiplicative order of 37 relative to 1000 is 100 because 37^100 is 1 (modulo 1000), and no number smaller than 100 would do.
One possible algorithm that is efficient also for large numbers is ... | #C | C | ulong mpow(ulong a, ulong p, ulong m)
{
ulong r = 1;
while (p) {
if ((1 & p)) r = r * a % m;
a = a * a % m;
p >>= 1;
}
return r;
}
ulong ipow(ulong a, ulong p) {
ulong r = 1;
while (p) {
if ((1 & p)) r = r * a;
a *= a;
p >>= 1;
}
return r;
}
ulong gcd(ulong m, ulong n)
{
ulong t;
while (m) { t... | Give a code snippet in #C
The multiplicative order of a relative to m is the least positive integer n such that a^n is 1 (modulo m).
Example
The multiplicative order of 37 relative to 1000 is 100 because 37^100 is 1 (modulo 1000), and no number smaller than 100 would do.
One possible algorithm that is efficient... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_decomposition | Prime decomposition | The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the prime decomposition of a given ... | #Phix | Phix | with javascript_semantics
requires("1.0.0")
include mpfr.e
atom t0 = time()
mpz z = mpz_init()
for i=1 to 25 do
integer pi = get_prime(i)
mpz_ui_pow_ui(z,2,pi)
mpz_sub_ui(z,z,1)
string zs = mpz_get_str(z),
fs = mpz_factorstring(mpz_pollard_rho(z))
if fs!=zs then zs &= " = "&fs end if
... | Give a code snippet in #Phix
The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Simple_database | Simple database | Task
Write a simple tool to track a small set of data.
The tool should have a command-line interface to enter at least two different values.
The entered data should be stored in a structured format and saved to disk.
It does not matter what kind of data is being tracked. It could be a collection (CDs, coins, base... | #REBOL | REBOL | rebol [author: "Nick Antonaccio"]
write/append %rdb "" db: load %rdb
switch system/options/args/1 [
"new" [write/append %rdb rejoin [now " " mold/only next system/options/args newline]]
"latest" [print copy/part tail sort/skip db 4 -4]
"latestcat" [
foreach cat unique extract at db 3 4 [
... | Give a code snippet in #REBOL
Task
Write a simple tool to track a small set of data.
The tool should have a command-line interface to enter at least two different values.
The entered data should be stored in a structured format and saved to disk.
It does not matter what kind of data is being tracked. It could be... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Logical_operations | Logical operations |
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 |... | #Go | Go | func printLogic(a, b bool) {
fmt.Println("a and b is", a && b)
fmt.Println("a or b is", a || b)
fmt.Println("not a is", !a)
} | Give a code snippet in #Go
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/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Factor | Factor | USING: kernel math ;
IN: rosettacode.fibonacci.ar
: fib ( n -- m )
dup 0 < [ "fib of negative" throw ] when
[
! If n < 2, then drop q, else find q(n - 1) + q(n - 2).
[ dup 2 < ] dip swap [ drop ] [
[ [ 1 - ] dip dup call ]
[ [ 2 - ] dip dup call ] 2bi +
] if
... | Give a code snippet in #Factor
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwan... | 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... | #Euler_Math_Toolbox | Euler Math Toolbox |
>function hailstone (n) ...
$ v=[n];
$ repeat
$ if mod(n,2) then n=3*n+1;
$ else n=n/2;
$ endif;
$ v=v|n;
$ until n==1;
$ end;
$ return v;
$ endfunction
>hailstone(27), length(%)
[ 27 82 41 124 62 31 94 47 142 71 214 107 322 161 484 242
121 364 182 91 274 137 412 206 103 ... | Give a code snippet in #Euler_Math_Toolbox
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 =... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polynomial_regression | Polynomial regression | Find an approximating polynomial of known degree for a given data.
Example:
For input data:
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
y = {1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321};
The approximating polynomial is:
3 x2 + 2 x + 1
Here, the polynomial's coefficients are (3, 2, 1).
This task is i... | #C.2B.2B | C++ | #include <algorithm>
#include <iostream>
#include <numeric>
#include <vector>
void polyRegression(const std::vector<int>& x, const std::vector<int>& y) {
int n = x.size();
std::vector<int> r(n);
std::iota(r.begin(), r.end(), 0);
double xm = std::accumulate(x.begin(), x.end(), 0.0) / x.size();
doub... | Give a code snippet in #C.2B.2B
Find an approximating polynomial of known degree for a given data.
Example:
For input data:
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
y = {1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321};
The approximating polynomial is:
3 x2 + 2 x + 1
Here, the polynomial's coefficien... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/Input | XML/Input | Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender="M" DateOfBirth="1990-03-04" /... | #Fantom | Fantom |
using xml
class XmlInput
{
public static Void main ()
{
// create the XML parser
parser := XParser(File("sample-xml.xml".toUri).in)
// parse the document, creating an XML document
XDoc doc := parser.parseDoc
// walk through each child element from the root of the document
doc.root.elems... | Give a code snippet in #Fantom
Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anagrams | Anagrams | When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in them.
Related tasks
Word plays
... | #Scheme | Scheme |
(import (scheme base)
(scheme char)
(scheme file)
(scheme write)
(srfi 125) ; hash tables
(srfi 132)) ; sorting library
;; read in the words
(define (read-groups)
(with-input-from-file
"unixdict.txt"
(lambda ()
(let ((groups (hash-table string=?)))
... | Give a code snippet in #Scheme
When two or more words are composed of the same characters, but in a different order, they are called anagrams.
Task[edit]
Using the word list at http://wiki.puzzlers.org/pub/wordlists/unixdict.txt,
find the sets of words that share the same characters that contain the most words in ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calculating_the_value_of_e | Calculating the value of e | Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | 1+Fold[1.+#1/#2&,1,Range[10,2,-1]] | Give a code snippet in #Mathematica.2FWolfram_Language
Task
Calculate the value of e.
(e is also known as Euler's number and Napier's constant.)
See details: Calculating the value of e
| christopher/rosetta-code | |
http://rosettacode.org/wiki/P-value_correction | P-value correction | Given a list of p-values, adjust the p-values for multiple comparisons. This is done in order to control the false positive, or Type 1 error rate.
This is also known as the "false discovery rate" (FDR). After adjustment, the p-values will be higher but still inside [0,1].
The adjusted p-values are sometimes called "q... | #C.2B.2B | C++ | #include <algorithm>
#include <functional>
#include <iostream>
#include <numeric>
#include <vector>
std::vector<int> seqLen(int start, int end) {
std::vector<int> result;
if (start == end) {
result.resize(end + 1);
std::iota(result.begin(), result.end(), 1);
} else if (start < end) {
... | Give a code snippet in #C.2B.2B
Given a list of p-values, adjust the p-values for multiple comparisons. This is done in order to control the false positive, or Type 1 error rate.
This is also known as the "false discovery rate" (FDR). After adjustment, the p-values will be higher but still inside [0,1].
The adjusted... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Honeycombs | Honeycombs | The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five
columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in columns two and four occupy a lower position... | #Icon_and_Unicon | Icon and Unicon | link printf
procedure main(A)
h := (0 < integer(\A[1])) | 4 # cells high
w := (0 < integer(\A[2])) | 5 # cells wide
u := (10 < integer(\A[3])) | 30 # length of cell side
HoneyComb(h,w,u)
end
$define INACTIVE "light yellow"
$define ACTIVE "light purple... | Give a code snippet in #Icon_and_Unicon
The task is to produce a matrix of 20 hexagon shaped widgets in a honeycomb arrangement. The matrix should be arranged in such a manner that there are five
columns of four hexagons. The hexagons in columns one, three and five are aligned horizontally, whereas the hexagons in col... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Floyd-Warshall_algorithm | Floyd-Warshall algorithm | The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel ... | #D | D | import std.stdio;
void main() {
int[][] weights = [
[1, 3, -2],
[2, 1, 4],
[2, 3, 3],
[3, 4, 2],
[4, 2, -1]
];
int numVertices = 4;
floydWarshall(weights, numVertices);
}
void floydWarshall(int[][] weights, int numVertices) {
import std.array;
real... | Give a code snippet in #D
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runtime_evaluation/In_an_environment | Runtime evaluation/In an environment | x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and language-specific details, see... | #Pike | Pike | > int x=10;
Result: 10
> x * 5;
Result: 50
> dump wrapper
Last compiled wrapper:
001: mapping(string:mixed) ___hilfe = ___Hilfe->variables;
002: # 1
003: mixed ___HilfeWrapper() { return (([mapping(string:int)](mixed)___hilfe)->x) * 5; ; }
004:
> | Give a code snippet in #Pike
x
x
x
Do so in a way which:
does not involve string manipulation of the input source code
is plausibly extensible to a runtime-chosen set of bindings rather than just x
does not make x a global variable
or note that these are impossible.
See also
For more general examples and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Last_letter-first_letter | Last letter-first letter | A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the category, they fall out of the ga... | #Python | Python | from collections import defaultdict
def order_words(words):
byfirst = defaultdict(set)
for word in words:
byfirst[word[0]].add( word )
#byfirst = dict(byfirst)
return byfirst
def linkfirst(byfirst, sofar):
'''\
For all words matching last char of last word in sofar as FIRST char and ... | Give a code snippet in #Python
A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the c... | 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 .
| #Arturo | Arturo | loop split.every:10 [1] ++ map 2..100 'x -> last chop factors x 'row [
print map to [:string] row 'r -> pad r 5
] | Give a code snippet in #Arturo
Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
Fo... | #Groovy | Groovy |
def normal = "http://foo bar/"
def encoded = URLEncoder.encode(normal, "utf-8")
println encoded
| Give a code snippet in #Groovy
Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tarjan | Tarjan |
This page uses content from Wikipedia. The original article was at Graph. 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)
Tarjan's algorithm is an algorithm in graph theory for finding the strongly... | #Raku | Raku | sub tarjan (%k) {
my %onstack;
my %index;
my %lowlink;
my @stack;
my @connected;
sub strong-connect ($vertex) {
state $index = 0;
%index{$vertex} = $index;
%lowlink{$vertex} = $index++;
%onstack{$vertex} = True;
@stack.push: $vertex;
... | Give a code snippet in #Raku
This page uses content from Wikipedia. The original article was at Graph. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Tarjan's algorithm is an algorithm in graph t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Narcissistic_decimal_number | Narcissistic decimal number | A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
is the number of digits in... | #ERRE | ERRE | PROGRAM NARCISISTIC
!$DOUBLE
BEGIN
N=0
LOOP
C$=MID$(STR$(N),2)
LENG=LEN(C$)
SUM=0
FOR I=1 TO LENG DO
C=VAL(MID$(C$,I,1))
SUM+=C^LENG
END FOR
IF N=SUM THEN
PRINT(N;)
COUNT=COUNT+1
EXIT IF COUNT=25
END IF
N=N+1
END LOO... | Give a code snippet in #ERRE
A Narcissistic decimal number is a non-negative integer,
n
{\displaystyle n}
, that is equal to the sum of the
m
{\displaystyle m}
-th powers of each of the digits in the decimal representation of
n
{\displaystyle n}
, where
m
{\displaystyle m}
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stable_marriage_problem | Stable marriage problem | Solve the Stable marriage problem using the Gale/Shapley algorithm.
Problem description
Given an equal number of men and women to be paired for marriage, each man ranks all the women in order of his preference and each woman ranks all the men in order of her preference.
A stable set of engagements for marriage is o... | #Perl | Perl | #!/usr/bin/env perl
use strict;
use warnings;
use feature qw/say/;
use List::Util qw(first);
my %Likes = (
M => {
abe => [qw/ abi eve cath ivy jan dee fay bea hope gay /],
bob => [qw/ cath hope abi dee eve fay bea jan ivy gay /],
col => [qw/ hope eve abi dee bea fay ivy gay cath jan /],
dan => ... | Give a code snippet in #Perl
Solve the Stable marriage problem using the Gale/Shapley algorithm.
Problem description
Given an equal number of men and women to be paired for marriage, each man ranks all the women in order of his preference and each woman ranks all the men in order of her preference.
A stable set of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Formatted_numeric_output | Formatted numeric output | Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| #M2000_Interpreter | M2000 Interpreter |
Print str$(7.125,"00000.000")
| Give a code snippet in #M2000_Interpreter
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Statistics/Basic | Statistics/Basic | Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n\,\!}
, the mean is
x
¯... | #Fortran | Fortran | program basic_stats
implicit none
integer, parameter :: i64 = selected_int_kind(18)
integer, parameter :: r64 = selected_real_kind(15)
integer(i64), parameter :: samples = 1000000000_i64
real(r64) :: r
real(r64) :: mean, stddev
real(r64) :: sumn = 0, sumnsq = 0
integer(i64) :: n = 0
integer(i64) ... | Give a code snippet in #Fortran
Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/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 |... | #Harbour | Harbour | procedure Test( a, b )
? "a+b", a + b
? "a-b", a - b
? "a*b", a * b
// The quotient isn't integer, so we use the Int() function, which truncates it downward.
? "a/b", Int( a / b )
// Remainder:
? "a%b", a % b
// Exponentiation is also a base arithmetic operation
? "a**b", a ** b
return | Give a code snippet in #Harbour
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 Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Additive_primes | Additive primes | Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry: A046704 additive primes.
... | #Racket | Racket | #lang racket
(require math/number-theory)
(define (sum-of-digits n (σ 0))
(if (zero? n) σ (let-values (((q r) (quotient/remainder n 10)))
(sum-of-digits q (+ σ r)))))
(define (additive-prime? n)
(and (prime? n) (prime? (sum-of-digits n))))
(define additive-primes<500 (filter additive-pri... | Give a code snippet in #Racket
Definitions
In mathematics, additive primes are prime numbers for which the sum of their decimal digits are also primes.
Task
Write a program to determine (and show here) all additive primes less than 500.
Optionally, show the number of additive primes.
Also see
the OEIS entry... | 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... | #Yabasic | Yabasic | sub floor(x)
return int(x + .05)
end sub
SUB ASort$(matriz$())
local last, gap, first, tempi$, tempj$, i, j
last = arraysize(matriz$(), 1)
gap = floor(last / 10) + 1
while(TRUE)
first = gap + 1
for i = first to last
tempi$ = matriz$(i)
j = i - gap
while(TRUE)
tempj$ =... | Give a code snippet in #Yabasic
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_integerness | Test integerness | Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit]
Given a rational, real, or co... | #J | J | isInt =: (= <.) *. (= {.@+.) | Give a code snippet in #J
Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit]
Gi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bulls_and_cows | Bulls and cows | Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the guess is the same as the random... | #Batch_File | Batch File | :: Bulls and Cows Task from Rosetta Code
:: Batch File Implementation
@echo off
setlocal enabledelayedexpansion
:: initialization
:begin
set "list_chars=123456789"
set "list_length=9"
set "code="
set "code_length=4" %== this should be less than 10 ==%
set "tries=0" %== number of tries ==%
:: generate the code t... | Give a code snippet in #Batch_File
Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comma_quibbling | Comma quibbling | Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An input of just one word, e.g. ["AB... | #Ol | Ol |
(define (quibble . args)
(display "{")
(let loop ((args args))
(unless (null? args) (begin
(display (car args))
(cond
((= 1 (length args)) #t)
((= 2 (length args))
(display " and "))
(else
(display ", ")))
(loop (... | Give a code snippet in #Ol
Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An input... | 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
| #BaCon | BaCon | PRAGMA INCLUDE <openssl/sha.h>
PRAGMA LDFLAGS -lcrypto
OPTION MEMTYPE unsigned char
DECLARE result TYPE unsigned char*
result = SHA256("Rosetta code", 12, 0)
FOR i = 0 TO SHA256_DIGEST_LENGTH-1
PRINT PEEK(result+i) FORMAT "%02x"
NEXT
PRINT | Give a code snippet in #BaCon
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: 764faf5c61ac315f1497f9dfa542713965b78... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Scala | Scala | object TextFileSlurper extends App {
val fileLines =
try scala.io.Source.fromFile("my_file.txt", "UTF-8").mkString catch {
case e: java.io.FileNotFoundException => e.getLocalizedMessage()
}
} | Give a code snippet in #Scala
Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incre... | 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... | #Wren | Wren | import "/big" for BigInt, BigRat
import "/fmt" for Fmt
var factorial = Fn.new { |n|
if (n < 2) return BigInt.one
var fact = BigInt.one
for (i in 2..n) fact = fact * i
return fact
}
var almkvistGiullera = Fn.new { |n, print|
var t1 = factorial.call(6*n) * 32
var t2 = 532*n*n + 126*n + 9
v... | Give a code snippet in #Wren
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic-geometric_mean | Arithmetic-geometric mean |
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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)
Task
Write a function to compute the arithmetic-geomet... | #jq | jq | def naive_agm(a; g; tolerance):
def abs: if . < 0 then -. else . end;
def _agm:
# state [an,gn]
if ((.[0] - .[1])|abs) > tolerance
then [add/2, ((.[0] * .[1])|sqrt)] | _agm
else .
end;
[a, g] | _agm | .[0] ; | Give a code snippet in #jq
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. 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)
Task
Write a function to c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #GAP | GAP | # GAP has built-in support for quaternions
A := QuaternionAlgebra(Rationals);
# <algebra-with-one of dimension 4 over Rationals>
b := BasisVectors(Basis(A));
# [ e, i, j, k ]
q := [1, 2, 3, 4]*b;
# e+(2)*i+(3)*j+(4)*k
# Conjugate
ComplexConjugate(q);
# e+(-2)*i+(-3)*j+(-4)*k
# Division
1/q;
# (1/30)*e+(-1/15)... | Give a code snippet in #GAP
Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number mi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Angle_difference_between_two_bearings | Angle difference between two bearings | Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range -180 to +180 degrees.
... | #Maple | Maple | getDiff := proc(b1,b2)
local r:
r := frem(b2 - b1, 360):
if r >= 180 then r := r - 360: fi:
return r:
end proc:
getDiff(20,45);
getDiff(-45,45);
getDiff(-85,90);
getDiff(-95,90);
getDiff(-45,125);
getDiff(-45,145);
getDiff(29.4803, -88.6381);
getDiff(-78.3251,-159.036);
getDiff(-70099.74233810938,29840.67437876723)... | Give a code snippet in #Maple
Finding the angle between two bearings is often confusing.[1]
Task
Find the angle which is the result of the subtraction b2 - b1, where b1 and b2 are the bearings.
Input bearings are expressed in the range -180 to +180 degrees.
The result is also expressed in the range ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #BASIC | BASIC | s$ = "alphaBETA"
PRINT UCASE$(s$)
PRINT LCASE$(s$) | Give a code snippet in #BASIC
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not r... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Safe_addition | Safe addition | Implementation of interval arithmetic and more generally fuzzy number arithmetic require operations that yield safe upper and lower bounds of the exact result.
For example, for an addition, it is the operations +↑ and +↓ defined as: a +↓ b ≤ a + b ≤ a +↑ b.
Additionally it is desired that the widt... | #Perl | Perl | use strict;
use warnings;
use Data::IEEE754::Tools <nextUp nextDown>;
sub safe_add {
my($a,$b) = @_;
my $c = $a + $b;
return $c, nextDown($c), nextUp($c)
}
printf "%.17f (%.17f, %.17f)\n", safe_add (1/9,1/7); | Give a code snippet in #Perl
Implementation of interval arithmetic and more generally fuzzy number arithmetic require operations that yield safe upper and lower bounds of the exact result.
For example, for an addition, it is the operations +↑ and +↓ defined as: a +↓ b ≤ a + b ≤ a +↑ b.
Additional... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #AppleScript | AppleScript | -- arithmetic_mean :: [Number] -> Number
on arithmetic_mean(xs)
-- sum :: Number -> Number -> Number
script sum
on |λ|(accumulator, x)
accumulator + x
end |λ|
end script
foldl(sum, 0, xs) / (length of xs)
end arithmetic_mean
-- geometric_mean :: [Number] -> Number
on ge... | Give a code snippet in #AppleScript
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_string_challenge | Longest string challenge | Background
This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the challenge and fun part came through th... | #C.2B.2B | C++ | #include <iostream>
#include <string.h>
int main()
{
std::string longLine, longestLines, newLine;
while (std::cin >> newLine)
{
auto isNewLineShorter = longLine.c_str();
auto isLongLineShorter = newLine.c_str();
while (*isNewLineShorter && *isLongLineShorter)
{
... | Give a code snippet in #C.2B.2B
Background
This "longest string challenge" is inspired by a problem that used to be given to students learning Icon. Students were expected to try to solve the problem in Icon and another language with which the student was already familiar. The basic problem is quite simple; the chall... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_configuration_file | Read a configuration file | The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a semicolon are ignored by the application
# pr... | #Vedit_macro_language | Vedit macro language | #11 = 0 // needspeeling = FALSE
#12 = 0 // seedsremoved = FALSE
Reg_Empty(21) // fullname
Reg_Empty(22) // favouritefruit
Reg_Empty(23) // otherfamily
File_Open("|(PATH_ONLY)\example.cfg")
if (Search("|<FULLNAME|s", BEGIN+ADVANCE+NOERR)) {
Match("=",... | Give a code snippet in #Vedit_macro_language
The task is to read a configuration file in standard configuration file format,
and set variables accordingly.
For this task, we have a configuration file as follows:
# This is a configuration file in standard configuration file format
#
# Lines beginning with a hash or a... | 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×... | #Wren | Wren | import "/big" for BigInt
import "/math" for Int
import "/fmt" for Fmt
var vecprod = Fn.new { |primes|
var le = primes.count
if (le == 0) return BigInt.one
var s = List.filled(le, null)
for (i in 0...le) s[i] = BigInt.new(primes[i])
while (le > 1) {
var c = (le/2).floor
for(i in 0..... | Give a code snippet in #Wren
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)
primor... | 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.
| #Emacs_Lisp | Emacs Lisp | (vconcat '[1 2 3] '[4 5] '[6 7 8 9])
=> [1 2 3 4 5 6 7 8 9] | Give a code snippet in #Emacs_Lisp
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/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #Logo | Logo | to div.checked :a :b
if :b = 0 [(throw "divzero 0)]
output :a / :b
end
to div.safely :a :b
output catch "divzero [div.checked :a :b]
end | Give a code snippet in #Logo
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #UNIX_Shell | UNIX Shell | #!/bin/ksh
# tested with ksh93s+
builtin printf
integer a=0
integer b=0
read a?"Enter value of a: " || { print -u2 "Input of a aborted." ; exit 1 ; }
read b?"Enter value of b: " || { print -u2 "Input of b aborted." ; exit 1 ; }
if (( a < b )) ; then
printf "%d is less than %d\n" a b
fi
if (( a == b )) ; the... | Give a code snippet in #UNIX_Shell
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 Operat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring/Top_and_tail | Substring/Top and tail | The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and last characters removed
If the program uses UTF-8 or UTF... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | StringDrop["input string",1]
StringDrop["input string",-1]
StringTake["input string",{2,-2}]
| Give a code snippet in #Mathematica.2FWolfram_Language
The task is to demonstrate how to remove the first and last characters from a string.
The solution should demonstrate how to obtain the following results:
String with first character removed
String with last character removed
String with both the first and la... | 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... | #Rust | Rust | use std::collections::btree_map::BTreeMap;
use std::{env, process};
use std::io::{self, Read, Write};
use std::fmt::Display;
use std::fs::File;
fn main() {
let filename = env::args().nth(1)
.ok_or("Please supply a file name")
.unwrap_or_else(|e| exit_err(e, 1));
let mut buf = String::new();
... | Give a code snippet in #Rust
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 (assi... | 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... | #Red | Red | Red [
Purpose: "100 Doors Problem (Perfect Squares)"
Author: "Barry Arthur"
Date: "07-Oct-2016"
]
doors: make vector! [char! 8 100]
repeat i 100 [change at doors i #"."]
repeat i 100 [
j: i
while [j <= 100] [
door: at doors j
change door either #"O" = first door [#"."] [#"O"]
j: j + i
... | Give a code snippet in #Red
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/Bitmap | Bitmap | Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB color,
one to set a given pixe... | #Perl | Perl | #! /usr/bin/perl
use strict;
use Image::Imlib2;
# create the "canvas"
my $img = Image::Imlib2->new(200,200);
# fill with a plain RGB(A) color
$img->set_color(255, 0, 0, 255);
$img->fill_rectangle(0,0, 200, 200);
# set a pixel to green (at 40,40)
$img->set_color(0, 255, 0, 255);
$img->draw_point(40,40);
# "g... | Give a code snippet in #Perl
Show a basic storage type to handle a simple RGB raster graphics image,
and some primitive associated functions.
If possible provide a function to allocate an uninitialised image,
given its width and height, and provide 3 additional functions:
one to fill an image with a plain RGB col... | 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... | #Haskell | Haskell | class Shape a where
perimeter :: a -> Double
area :: a -> Double
{- A type class Shape. Types belonging to Shape must support two
methods, perimeter and area. -}
data Rectangle = Rectangle Double Double
{- A new type with a single constructor. In the case of data types
which have only one constructor, we... | Give a code snippet in #Haskell
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 c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Self-describing_numbers | Self-describing numbers | Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when digit positions are labeled 0 to ... | #VBScript | VBScript |
Function IsSelfDescribing(n)
IsSelfDescribing = False
Set digit = CreateObject("Scripting.Dictionary")
For i = 1 To Len(n)
k = Mid(n,i,1)
If digit.Exists(k) Then
digit.Item(k) = digit.Item(k) + 1
Else
digit.Add k,1
End If
Next
c = 0
For j = 0 To Len(n)-1
l = Mid(n,j+1,1)
If digit.Exists(CStr(... | Give a code snippet in #VBScript
Self-describing numbers
You are encouraged to solve this task according to the task description, using any language you may know.
There are several so-called "self-describing" or "self-descriptive" integers.
An integer is said to be "self-describing" if it has the property that, when... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jump_anywhere | Jump anywhere | Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to use these jumps for different... | #Java | Java | loop1: while (x != 0) {
loop2: for (int i = 0; i < 10; i++) {
loop3: do {
//some calculations...
if (/*some condition*/) {
//this continue will skip the rest of the while loop code and start it over at the next iteration
continue loop1;
}
... | Give a code snippet in #Java
Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sleep | Sleep | Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread for the given amount of time.
... | #OCaml | OCaml | #load "unix.cma";;
let seconds = read_int ();;
print_endline "Sleeping...";;
Unix.sleep seconds;; (* number is integer in seconds *)
print_endline "Awake!";; | Give a code snippet in #OCaml
Task
Write a program that does the following in this order:
Input an amount of time to sleep in whatever units are most natural for your language (milliseconds, seconds, ticks, etc.). This unit should be noted in comments or in a description.
Print "Sleeping..."
Sleep the main thread... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pythagorean_triples | Pythagorean triples | A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\displaystyle a,b,c}
are co-prime,... | #F.23 | F# | let isqrt n =
let rec iter t =
let d = n - t*t
if (0 <= d) && (d < t+t+1) // t*t <= n < (t+1)*(t+1)
then t else iter ((t+(n/t))/2)
iter 1
let rec gcd a b =
let t = a % b
if t = 0 then b else gcd b t
let coprime a b = gcd a b = 1
let num_to ms =
let mutable ctr = 0
l... | Give a code snippet in #F.23
A Pythagorean triple is defined as three positive integers
(
a
,
b
,
c
)
{\displaystyle (a,b,c)}
where
a
<
b
<
c
{\displaystyle a<b<c}
, and
a
2
+
b
2
=
c
2
.
{\displaystyle a^{2}+b^{2}=c^{2}.}
They are called primitive triples if
a
,
b
,
c
{\displ... | 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
... | #Stata | Stata | 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 #Stata
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/Multisplit | Multisplit | It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is to write code to demonstrate ... | #Factor | Factor | USING: arrays fry kernel make sequences ;
IN: rosetta-code.multisplit
: ?pair ( ? x -- {?,x}/f )
over [ 2array ] [ 2drop f ] if ;
: best-separator ( seq -- pos index )
dup [ first ] map infimum '[ first _ = ] find nip first2 ;
: first-subseq ( separators seq -- n separator )
dupd [ swap [ subseq-sta... | Give a code snippet in #Factor
It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/AVL_tree | AVL tree |
This page uses content from Wikipedia. The original article was at AVL tree. 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)
In computer science, an AVL tree is a self-balancing binary search tree.... | #Haskell | Haskell | data Tree a
= Leaf
| Node
Int
(Tree a)
a
(Tree a)
deriving (Show, Eq)
foldTree :: Ord a => [a] -> Tree a
foldTree = foldr insert Leaf
height :: Tree a -> Int
height Leaf = -1
height (Node h _ _ _) = h
depth :: Tree a -> Tree a -> Int
depth a b = succ (max (height a) (height b))
ins... | Give a code snippet in #Haskell
This page uses content from Wikipedia. The original article was at AVL tree. 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)
In computer science, an AVL tree is a s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_names | Number names | Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than positive integers (like zero, negat... | #BlitzMax | BlitzMax | SuperStrict
Framework BRL.StandardIO
spellIt( 99)
spellIt( 300)
spellIt( 310)
spellIt( 1501)
spellIt( 12609)
spellIt( 512609)
spellIt( 43112609)
spellIt(1234567890)
Type TSpell
Field smallNumbers:String[] = ["zero", "one", "two", "three", "four", "five", ..
"six", "seven", "... | Give a code snippet in #BlitzMax
Task
Show how to spell out a number in English.
You can use a preexisting implementation or roll your own, but you should support inputs up to at least one million (or the maximum value of your language's default bounded integer type, if that's less).
Support for inputs other than p... | christopher/rosetta-code |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.