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
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|---|---|---|---|---|---|---|---|---|
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... | #Applesoft_BASIC | Applesoft BASIC | 0 DIM D$(1111):D$(0)="0":D$(1)="1":D$(10)="2":D$(11)="3":D$(100)="4":D$(101)="5":D$(110)="6":D$(111)="7":D$(1000)="8":D$(1001)="9":D$(1010)="A":D$(1011)="B":D$(1100)="C":D$(1101)="D":D$(1110)="E":D$(1111)="F"
1 Z$ = CHR$ (8) + CHR$ (8) + CHR$ (8) + CHR$ (8) + CHR$ (8) + CHR$ (8) + CHR$ (8) + CHR$ (8) + CHR$ ... | Give a code snippet in #Applesoft_BASIC
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conway%27s_Game_of_Life | Conway's Game of Life | The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, in an m-by-m (or m×m) sq... | #SenseTalk | SenseTalk | set starting_condition to ((0, 0), (1, 0), (2, 0), (-1, -1), (0, -1), (1, -1))
RunGameOfLife starting_condition
to printColony colonies
set xCoords to the first item of each item of colonies
set yCoords to the second item of each item of colonies
set min_x to the min of xCoords
set max_x to the max ... | Give a code snippet in #SenseTalk
The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_missing_permutation | Find the missing permutation | ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
CDBA
... | #C.2B.2B | C++ | #include <algorithm>
#include <vector>
#include <set>
#include <iterator>
#include <iostream>
#include <string>
static const std::string GivenPermutations[] = {
"ABCD","CABD","ACDB","DACB",
"BCDA","ACBD","ADCB","CDAB",
"DABC","BCAD","CADB","CDBA",
"CBAD","ABDC","ADBC","BDCA",
"DCBA","BACD","BADC","BDAC",
... | Give a code snippet in #C.2B.2B
ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
... | 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.
| #Visual_Basic_.NET | Visual Basic .NET | Imports System.Text
Module Module1
Sub Swap(Of T)(ByRef a As T, ByRef b As T)
Dim c = a
a = b
b = c
End Sub
Structure Point
Dim x As Integer
Dim y As Integer
'rotate/flip a quadrant appropriately
Sub Rot(n As Integer, rx As Boolean, ry As Boole... | Give a code snippet in #Visual_Basic_.NET
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort | Sorting algorithms/Merge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #zkl | zkl | fcn _merge(left,right){
if (not left) return(right);
if (not right) return(left);
l:=left[0]; r:=right[0];
if (l<=r) return(L(l).extend(self.fcn(left[1,*],right)));
else return(L(r).extend(self.fcn(left,right[1,*])));
}
fcn merge_sort(L){
if (L.len()<2) return(L);
n:=L.len()/2;
return(_m... | Give a code snippet in #zkl
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime | Add a variable to a class instance at runtime | Demonstrate how to dynamically add variables to an object (a class instance) at runtime.
This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re... | #Groovy | Groovy | class A {
final x = { it + 25 }
private map = new HashMap()
Object get(String key) { map[key] }
void set(String key, Object value) { map[key] = value }
} | Give a code snippet in #Groovy
Demonstrate how to dynamically add variables to an object (a class instance) at runtime.
This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metap... | 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.
| #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
#Include "vbcompat.bi"
Dim s As String = Format(7.125, "00000.0##")
Print s
Sleep | Give a code snippet in #FreeBASIC
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/Date_format | Date format | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| #Racket | Racket | #lang racket
(require srfi/19)
;;; The first required format is an ISO-8601 year-month-day format, predefined
;;; as ~1 in date->string
(displayln (date->string (current-date) "~1"))
;;; You should be able to see how each of the components of the following format string
;;; work...
;;; ~d is zero padded day of mont... | Give a code snippet in #Racket
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Time_a_function | Time a function | Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
between start and finish, which could ... | #F.23 | F# |
open System.Diagnostics
let myfunc data =
let timer = new Stopwatch()
timer.Start()
let result = data |> expensive_processing
timer.Stop()
printf "elapsed %d ms" timer.ElapsedMilliseconds
result
| Give a code snippet in #F.23
Task
Write a program which uses a timer (with the least granularity available
on your system) to time how long a function takes to execute.
Whenever possible, use methods which measure only the processing time used
by the current process; instead of the difference in system time
between ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_character_by_character/UTF8 | Read a file character by character/UTF8 | Task
Read a file one character at a time, as opposed to reading the entire file at once.
The solution may be implemented as a procedure, which returns the next character in the file on each consecutive call (returning EOF when the end of the file is reached).
The procedure should support the reading of files contain... | #Kotlin | Kotlin | // version 1.1.2
import java.io.File
const val EOF = -1
fun main(args: Array<String>) {
val reader = File("input.txt").reader() // uses UTF-8 by default
reader.use {
while (true) {
val c = reader.read()
if (c == EOF) break
print(c.toChar()) // echo to console
... | Give a code snippet in #Kotlin
Task
Read a file one character at a time, as opposed to reading the entire file at once.
The solution may be implemented as a procedure, which returns the next character in the file on each consecutive call (returning EOF when the end of the file is reached).
The procedure should supp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_join | Hash join | An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" algorithm, and demonstrate tha... | #VBScript | VBScript |
Dim t_age(4,1)
t_age(0,0) = 27 : t_age(0,1) = "Jonah"
t_age(1,0) = 18 : t_age(1,1) = "Alan"
t_age(2,0) = 28 : t_age(2,1) = "Glory"
t_age(3,0) = 18 : t_age(3,1) = "Popeye"
t_age(4,0) = 28 : t_age(4,1) = "Alan"
Dim t_nemesis(4,1)
t_nemesis(0,0) = "Jonah" : t_nemesis(0,1) = "Whales"
t_nemesis(1,0) = "Jonah" : t_nemesi... | Give a code snippet in #VBScript
An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash jo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Break_OO_privacy | Break OO privacy | Show how to access private or protected members of a class in an object-oriented language from outside an instance of the class, without calling non-private or non-protected members of the class as a proxy.
The intent is to show how a debugger, serializer, or other meta-programming tool might access information that is... | #D | D | module breakingprivacy;
struct Foo
{
int[] arr;
private:
int x;
string str;
float f;
} | Give a code snippet in #D
Show how to access private or protected members of a class in an object-oriented language from outside an instance of the class, without calling non-private or non-protected members of the class as a proxy.
The intent is to show how a debugger, serializer, or other meta-programming tool might... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leap_year | Leap year | Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| #Delphi.2FPascal | Delphi/Pascal | program TestLeapYear;
{$APPTYPE CONSOLE}
uses
SysUtils;
var
Year: Integer;
begin
Write('Enter the year: ');
Readln(Year);
if IsLeapYear(Year) then
Writeln(Year, ' is a Leap year')
else
Writeln(Year, ' is not a Leap year');
Readln;
end. | Give a code snippet in #Delphi.2FPascal
Task
Determine whether a given year is a leap year in the Gregorian calendar.
See also
Leap year (wiki)
| 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... | #Burlesque | Burlesque |
blsq ) "HELLO WORLD"{{'A'Zr\\/Fi}m[13?+26.%'A'Zr\\/si}ww
"URYYB JBEYQ"
blsq ) "URYYB JBEYQ"{{'A'Zr\\/Fi}m[13?+26.%'A'Zr\\/si}ww
"HELLO WORLD"
| Give a code snippet in #Burlesque
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 ro... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Next_highest_int_from_digits | Next highest int from digits | Given a zero or positive integer, the task is to generate the next largest
integer using only the given digits*1.
Numbers will not be padded to the left with zeroes.
Use all given digits, with their given multiplicity. (If a digit appears twice in the input number, it should appear twice in the result).
If th... | #C | C | #include <stdbool.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
void swap(char* str, int i, int j) {
char c = str[i];
str[i] = str[j];
str[j] = c;
}
void reverse(char* str, int i, int j) {
for (; i < j; ++i, --j)
swap(str, i, j);
}
bool next_permutation(... | Give a code snippet in #C
Given a zero or positive integer, the task is to generate the next largest
integer using only the given digits*1.
Numbers will not be padded to the left with zeroes.
Use all given digits, with their given multiplicity. (If a digit appears twice in the input number, it should appear twi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_prototype | Function prototype | Some languages provide the facility to declare functions and subroutines through the use of function prototyping.
Task
Demonstrate the methods available for declaring prototypes within the language. The provided solutions should include:
An explanation of any placement restrictions for prototype declarations
A p... | #Phix | Phix | forward function noargs() -- Declare a function with no arguments
forward procedure twoargs(integer a, integer b) -- Declare a procedure with two arguments
forward procedure twoargs(integer, integer /*b*/) -- Parameter names are optional in forward (and actual) definitions
forward function anyargs(sequence s) -- vararg... | Give a code snippet in #Phix
Some languages provide the facility to declare functions and subroutines through the use of function prototyping.
Task
Demonstrate the methods available for declaring prototypes within the language. The provided solutions should include:
An explanation of any placement restrictions f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #BASIC256 | BASIC256 | function stripchars(texto, remove)
s = texto
for i = 1 to length(remove)
s = replace(s, mid(remove, i, 1), "", true) #true se puede omitir
next i
return s
end function
print stripchars("She was a soul stripper. She took my heart!", "aei") | Give a code snippet in #BASIC256
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compiler/code_generator | Compiler/code generator | A code generator translates the output of the syntax analyzer and/or semantic analyzer
into lower level code, either assembly, object, or virtual.
Task[edit]
Take the output of the Syntax analyzer task - which is a flattened Abstract Syntax Tree (AST) - and convert it to virtual machine code, that can be run by the
Vi... | #COBOL | COBOL | >>SOURCE FORMAT IS FREE
identification division.
*> this code is dedicated to the public domain
*> (GnuCOBOL) 2.3-dev.0
program-id. generator.
environment division.
configuration section.
repository. function all intrinsic.
data division.
working-storage section.
01 program-name pic x(32) value spaces global.... | Give a code snippet in #COBOL
A code generator translates the output of the syntax analyzer and/or semantic analyzer
into lower level code, either assembly, object, or virtual.
Task[edit]
Take the output of the Syntax analyzer task - which is a flattened Abstract Syntax Tree (AST) - and convert it to virtual machine ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/15_puzzle_game | 15 puzzle game |
Task
Implement the Fifteen Puzzle Game.
The 15-puzzle is also known as:
Fifteen Puzzle
Gem Puzzle
Boss Puzzle
Game of Fifteen
Mystic Square
14-15 Puzzle
and some others.
Related Tasks
15 Puzzle Solver
16 Puzzle Game
| #Astro | Astro | type Puzzle(var items: {}, var position: -1)
fun mainframe(puz):
let d = puz.items
print('+-----+-----+-----+-----+')
print(d[1], d[2], d[3], d[4], first: '|', sep: '|', last: '|')
print('+-----+-----+-----+-----+')
print(d[5], d[6], d[7], d[8], first: '|', sep: '|', last: '|')
print('+-----+-... | Give a code snippet in #Astro
Task
Implement the Fifteen Puzzle Game.
The 15-puzzle is also known as:
Fifteen Puzzle
Gem Puzzle
Boss Puzzle
Game of Fifteen
Mystic Square
14-15 Puzzle
and some others.
Related Tasks
15 Puzzle Solver
16 Puzzle Game
| 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.
... | #Rust | Rust | fn main() {
let limit = 500;
let column_w = limit.to_string().len() + 1;
let mut pms = Vec::with_capacity(limit / 2 - limit / 3 / 2 - limit / 5 / 3 / 2 + 1);
let mut count = 0;
for u in (2..3).chain((3..limit).step_by(2)) {
if pms.iter().take_while(|&&p| p * p <= u).all(|&p| u % p != 0) {
... | Give a code snippet in #Rust
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/One-dimensional_cellular_automata | One-dimensional cellular automata | Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current generation.
If, in the follow... | #Visual_Basic_.NET | Visual Basic .NET | Imports System.Text
Module CellularAutomata
Private Enum PetriStatus
Active
Stable
Dead
End Enum
Function Main(ByVal cmdArgs() As String) As Integer
If cmdArgs.Length = 0 Or cmdArgs.Length > 1 Then
Console.WriteLine("Command requires string of either 1s and ... | Give a code snippet in #Visual_Basic_.NET
Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in... | 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... | #Liberty_BASIC | Liberty BASIC | string$ = "Rosetta Code"
Print Mid$(string$, 2)
Print Left$(string$, (Len(string$) - 1))
Print Mid$(string$, 2, (Len(string$) - 2)) | Give a code snippet in #Liberty_BASIC
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 rem... | 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... | #Wren | Wren | var a = " \t\r\nString with leading whitespace removed"
var b = "String with trailing whitespace removed \t\r\n"
var c = " \t\r\nString with both leading and trailing whitespace removed \t\r\n"
var d = " \t\r\n\f\vString with leading whitespace, form feed and verical tab characters removed"
System.print("'%(a.trim... | Give a code snippet in #Wren
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 rem... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Selectively_replace_multiple_instances_of_a_character_within_a_string | Selectively replace multiple instances of a character within a string | Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the fifth 'a' with 'D'
the first 'b... | #Vlang | Vlang | fn selectively_replace_chars(s string, char_map map[string]string) string {
mut bytes := s.bytes()
mut counts := {
'a': 0
'b': 0
'r': 0
}
for i := s.len - 1; i >= 0; i-- {
c := s[i].ascii_str()
if c in ['a', 'b', 'r'] {
bytes[i] = char_map[c][counts[c]... | Give a code snippet in #Vlang
Task
This is admittedly a trivial task but I thought it would be interesting to see how succinctly (or otherwise) different languages can handle it.
Given the string: "abracadabra", replace programatically:
the first 'a' with 'A'
the second 'a' with 'B'
the fourth 'a' with 'C'
the f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Stooge_sort | Sorting algorithms/Stooge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #R | R | stoogesort = function(vect) {
i = 1
j = length(vect)
if(vect[j] < vect[i]) vect[c(j, i)] = vect[c(i, j)]
if(j - i > 1) {
t = (j - i + 1) %/% 3
vect[i:(j - t)] = stoogesort(vect[i:(j - t)])
vect[(i + t):j] = stoogesort(vect[(i + t):j])
vect[i:(j - t)] = stoogesort(vect[i:(j - t)])
}
vect
}
v = sample(21... | Give a code snippet in #R
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #PL.2FI | PL/I | catalan: procedure options (main); /* 23 February 2012 */
declare (i, n) fixed;
put skip list ('How many catalan numbers do you want?');
get list (n);
do i = 0 to n;
put skip list (c(i));
end;
c: procedure (n) recursive returns (fixed decimal (15));
declare n fixed;
if n <= 1 then r... | Give a code snippet in #PL.2FI
Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Randomize , 5
'generate 10 cryptographic random integers in the range 1 To 100
For i As Integer = 1 To 10
Print Int(Rnd * 100) + 1
Next
Sleep | Give a code snippet in #FreeBASIC
Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #Jsish | Jsish | var strReversed =
"---------- Ice and Fire ------------\n
fire, in end will world the say Some
ice. in say Some
desire of tasted I've what From
fire. favor who those with hold I
\n... elided paragraph last ...\n
Frost Robert -----------------------";
function reverseString(s) {
return s.split('\n').map(
fun... | Give a code snippet in #Jsish
Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spac... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Musical_scale | Musical scale | Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, Fa, Sol, La, Si/Ti, Do(1 octa... | #Commodore_BASIC | Commodore BASIC | 10 rem musical scale
15 rem rosetta code
20 print chr$(147)
25 s=54272
30 for l=s to s+23:poke l,0:next
35 poke s+5,9:poke s+6,0
40 poke s+24,15
45 for i=1 to 8 ... | Give a code snippet in #Commodore_BASIC
Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_a_quadratic_function | Roots of a quadratic function | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+bx+c=0}
.
Your program must correctly handle n... | #.D0.9C.D0.9A-61.2F52 | МК-61/52 | П2 С/П /-/ <-> / 2 / П3 x^2 С/П
ИП2 / - Вx <-> КвКор НОП x>=0 28 ИП3
x<0 24 <-> /-/ + / Вx С/П /-/ КвКор
ИП3 С/П | Give a code snippet in #.D0.9C.D0.9A-61.2F52
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Write a program to find the roots of a quadratic equation, i.e., solve the equation
a
x
2
+
b
x
+
c
=
0
{\displaystyle ax^{2}+b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_Chess960_starting_position | Generate Chess960 starting position | Chess960 is a variant of chess created by world champion Bobby Fischer. Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints:
as in the standard chess game, all eight white pawns must be placed on the second rank.
W... | #Scala | Scala | import scala.annotation.tailrec
object Chess960 extends App {
private val pieces = List('♖', '♗', '♘', '♕', '♔', '♘', '♗', '♖')
@tailrec
private def generateFirstRank(pieces: List[Char]): List[Char] = {
def check(rank: String) =
rank.matches(".*♖.*♔.*♖.*") && rank.matches(".*♗(..|....|......|)♗.*"... | Give a code snippet in #Scala
Chess960 is a variant of chess created by world champion Bobby Fischer. Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints:
as in the standard chess game, all eight white pawns must b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knight%27s_tour | Knight's tour |
Task
Problem: you have a standard 8x8 chessboard, empty but for a single knight on some square. Your task is to emit a series of legal knight moves that result in the knight visiting every square on the chessboard exactly once. Note that it is not a requirement that the tour be "closed"; that is, the knight need not e... | #Lua | Lua | N = 8
moves = { {1,-2},{2,-1},{2,1},{1,2},{-1,2},{-2,1},{-2,-1},{-1,-2} }
function Move_Allowed( board, x, y )
if board[x][y] >= 8 then return false end
local new_x, new_y = x + moves[board[x][y]+1][1], y + moves[board[x][y]+1][2]
if new_x >= 1 and new_x <= N and new_y >= 1 and new_y <= N and boar... | Give a code snippet in #Lua
Task
Problem: you have a standard 8x8 chessboard, empty but for a single knight on some square. Your task is to emit a series of legal knight moves that result in the knight visiting every square on the chessboard exactly once. Note that it is not a requirement that the tour be "closed"; t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/S-expressions | S-expressions | S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable datastructure (list, array, etc).
... | #Racket | Racket |
#lang racket
(define input
#<<---
((data "quoted data" 123 4.5)
(data (!@# (4.5) "(more" "data)")))
---
)
(read (open-input-string input))
| Give a code snippet in #Racket
S-Expressions are one convenient way to parse and store data.
Task
Write a simple reader and writer for S-Expressions that handles quoted and unquoted strings, integers and floats.
The reader should read a single but nested S-Expression from a string and store it in a suitable dat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mastermind | Mastermind | Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may be repeated in the code
The (... | #Phix | Phix | -- demo/rosetta/mastermind.exw
constant SET_LIMIT = 1_000_000 -- above this, it uses random sampling.
constant help_text = """
The game of mastermind, with a Knuth solver.
Specify the number of colours (1..20), the code length (1..10), the
number of guesses allowed (1-20), and whether colours can be repeated
(auto... | Give a code snippet in #Phix
Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Standard_ML | Standard ML | fun printIntList ls =
(
List.app (fn n => print(Int.toString n ^ " ")) ls;
print "\n"
);
fun factors n =
let
fun factors'(n, k) =
if k > n then
[]
else if n mod k = 0 then
k :: factors'(n, k+1)
else
factors'(n, k+1)
in
factors'(n,1)
end;
| Give a code snippet in #Standard_ML
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 Opera... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #Vedit_macro_language | Vedit macro language | Num_Type(File_Size("input.txt"))
Num_Type(File_Size("/input.txt")) | Give a code snippet in #Vedit_macro_language
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_decimal_number_to_rational | Convert decimal number to rational | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It is not always possible to do this... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <stdint.h>
/* f : number to convert.
* num, denom: returned parts of the rational.
* md: max denominator value. Note that machine floating point number
* has a finite resolution (10e-16 ish for 64 bit double), so specifying
* a "best match... | Give a code snippet in #C
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It is not... | 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
... | #C | C | int is_prime(unsigned int n)
{
unsigned int p;
if (!(n & 1) || n < 2 ) return n == 2;
/* comparing p*p <= n can overflow */
for (p = 3; p <= n/p; p += 2)
if (!(n % p)) return 0;
return 1;
} | Give a code snippet in #C
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTP | HTTP | Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| #F.23 | F# |
let wget (url : string) =
use c = new System.Net.WebClient()
c.DownloadString(url)
printfn "%s" (wget "http://www.rosettacode.org/")
| Give a code snippet in #F.23
Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| 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.23 | C# | using System;
using System.Collections.Generic;
using System.Numerics;
using System.Threading;
namespace MultiplicativeOrder {
// Taken from https://stackoverflow.com/a/33918233
public static class PrimeExtensions {
// Random generator (thread safe)
private static ThreadLocal<Random> s_Gen = n... | Give a code snippet in #C.23
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 effici... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Radix_sort | Sorting algorithms/Radix sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Tailspin | Tailspin |
templates radixsort&{base:}
sink bucketize
def value: $;
$ ~/ $@radixsort.digit -> #
when <=0 ?($value <0..>)> do
..|@radixsort.positives: $value;
when <=0> do
..|@radixsort.negatives(last): $value;
otherwise
def bucket: $ mod $base -> \(<?($value<0..>)> $ + 1 ! <=0> $base ! <>... | Give a code snippet in #Tailspin
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/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #Forth | Forth | : first over c@ ;
: last >r 2dup + 1- c@ r> swap ;
: palindrome? ( c-addr u -- f )
begin
dup 1 <= if 2drop true exit then
first last <> if 2drop false exit then
1 /string 1-
again ;
| Give a code snippet in #Forth
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Four_bit_adder | Four bit adder | Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate can be made using two nots, two ands ... | #MATLAB_.2F_Octave | MATLAB / Octave | function [S,v] = fourBitAdder(input1,input2)
%Make sure that only 4-Bit numbers are being added. This assumes that
%if input1 and input2 are a vector of multiple decimal numbers, then
%the binary form of these vectors are an n by 4 matrix.
assert((size(input1,2) == 4) && (size(input2,2) == 4),'This wi... | Give a code snippet in #MATLAB_.2F_Octave
Task
"Simulate" a four-bit adder.
This design can be realized using four 1-bit full adders.
Each of these 1-bit full adders can be built with two half adders and an or gate. ;
Finally a half adder can be made using an xor gate and an and gate.
The xor gate ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Least_common_multiple | Least common multiple | Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that has both m and n as factor... | #ooRexx | ooRexx |
say lcm(18, 12)
-- calculate the greatest common denominator of a numerator/denominator pair
::routine gcd private
use arg x, y
loop while y \= 0
-- check if they divide evenly
temp = x // y
x = y
y = temp
end
return x
-- calculate the least common multiple of a numerator/denomin... | Give a code snippet in #ooRexx
Least common multiple
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Compute the least common multiple (LCM) of two integers.
Given m and n, the least common multiple is the smallest positive integer that ha... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cuban_primes | Cuban primes | The name cuban has nothing to do with Cuba (the country), but has to do with the
fact that cubes (3rd powers) play a role in its definition.
Some definitions of cuban primes
primes which are the difference of two consecutive cubes.
primes of the form: (n+1)3 - n3.
primes of the form: n3 - ... | #C.2B.2B | C++ | #include <iostream>
#include <vector>
#include <chrono>
#include <climits>
#include <cmath>
using namespace std;
vector <long long> primes{ 3, 5 };
int main()
{
cout.imbue(locale(""));
const int cutOff = 200, bigUn = 100000,
chunks = 50, little = bigUn / chunks;
const char tn[] = " cuban prime"... | Give a code snippet in #C.2B.2B
The name cuban has nothing to do with Cuba (the country), but has to do with the
fact that cubes (3rd powers) play a role in its definition.
Some definitions of cuban primes
primes which are the difference of two consecutive cubes.
primes of the form: (n+1)3 - n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_file | Create a file | In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #Mirah | Mirah | import java.io.File
File.new('output.txt').createNewFile()
File.new('docs').mkdir()
File.new("docs#{File.separator}output.txt").createNewFile()
| Give a code snippet in #Mirah
In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #SAS | SAS | data fib;
a=0;
b=1;
do n=0 to 20;
f=a;
output;
a=b;
b=f+a;
end;
keep n f;
run; | Give a code snippet in #SAS
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 g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_numbers | Perfect numbers | Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
Note: The faster Luca... | #Lingo | Lingo | on isPercect (n)
sum = 1
cnt = n/2
repeat with i = 2 to cnt
if n mod i = 0 then sum = sum + i
end repeat
return sum=n
end | Give a code snippet in #Lingo
Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_the_epoch | Show the epoch | Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scenes by the implementers), b... | #PARI.2FGP | PARI/GP | system("date -ur 0") | Give a code snippet in #PARI.2FGP
Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_matching | String matching |
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 |... | #TXR | TXR | (tree-case *args*
((big small)
(cond
((< (length big) (length small))
(put-line `@big is shorter than @small`))
((str= big small)
(put-line `@big and @small are equal`))
((starts-with small big)
(put-line `@small is a prefix of @big`))
((ends-with small big)
(put-line `@... | Give a code snippet in #TXR
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/Averages/Simple_moving_average | Averages/Simple moving average | Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a method for computing an avera... | #Tcl | Tcl | oo::class create SimpleMovingAverage {
variable vals idx
constructor {{period 3}} {
set idx end-[expr {$period-1}]
set vals {}
}
method val x {
set vals [lrange [list {*}$vals $x] $idx end]
expr {[tcl::mathop::+ {*}$vals]/double([llength $vals])}
}
} | Give a code snippet in #Tcl
Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_arithmetic | Modular arithmetic | Modular arithmetic is a form of arithmetic (a calculation technique involving the concepts of addition and multiplication) which is done on numbers with a defined equivalence relation called congruence.
For any positive integer
p
{\displaystyle p}
called the congruence modulus,
two numbers
a
{\displaysty... | #Wren | Wren | // Semi-abstract though we can define a 'pow' method in terms of the other operations.
class Ring {
+(other) {}
*(other) {}
one {}
pow(p) {
if (p.type != Num || !p.isInteger || p < 0) {
Fiber.abort("Argument must be non-negative integer.")
}
var pwr = one
... | Give a code snippet in #Wren
Modular arithmetic is a form of arithmetic (a calculation technique involving the concepts of addition and multiplication) which is done on numbers with a defined equivalence relation called congruence.
For any positive integer
p
{\displaystyle p}
called the congruence modulus,
tw... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_sentence_from_book | Random sentence from book | Read in the book "The War of the Worlds", by H. G. Wells.
Skip to the start of the book, proper.
Remove extraneous punctuation, but keep at least sentence-ending punctuation characters . ! and ?
Keep account of what words follow words and how many times it is seen, (treat sentence terminators as words too).
Keep a... | #Raku | Raku | my $text = '36-0.txt'.IO.slurp.subst(/.+ '*** START OF THIS' .+? \n (.*?) 'End of the Project Gutenberg EBook' .*/, {$0} );
$text.=subst(/ <+punct-[.!?\’,]> /, ' ', :g);
$text.=subst(/ (\s) '’' (\s) /, '', :g);
$text.=subst(/ (\w) '’' (\s) /, {$0~$1}, :g);
$text.=subst(/ (\s) '’' (\w) /, {$0~$1}, :g);
my (%one, ... | Give a code snippet in #Raku
Read in the book "The War of the Worlds", by H. G. Wells.
Skip to the start of the book, proper.
Remove extraneous punctuation, but keep at least sentence-ending punctuation characters . ! and ?
Keep account of what words follow words and how many times it is seen, (treat sentence term... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_comparison | String comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Icon_and_Unicon | Icon and Unicon | procedure main(A)
s1 := A[1] | "a"
s2 := A[2] | "b"
# These first four are case-sensitive
s1 == s2 # Are they equal?
s1 ~== s2 # Are they unequal?
s1 << s2 # Does s1 come before s2?
s1 >> s2 # Does s1 come after s2?
map(s1) == map(s2) # Caseless comparison
... | Give a code snippet in #Icon_and_Unicon
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String O... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Line_printer | Hello world/Line printer | Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With some systems, a line printer can be... | #PureBasic | PureBasic | MyPrinter$ = LPRINT_GetDefaultPrinter()
If LPRINT_OpenPrinter(MyPrinter$)
If LPRINT_StartDoc("Printing a RC-Task")
LPRINT_Print(Chr(27) + "E") ; PCL reset for HP Printers
LPRINT_PrintN("Hello World!")
LPRINT_NewPage()
LPRINT_EndDoc()
EndIf
LPRINT_ClosePrinter()
EndIf | Give a code snippet in #PureBasic
Task
Cause a line printer attached to the computer to print a line containing the message: Hello World!
Note
A line printer is not the same as standard output.
A line printer was an older-style printer which prints one line at a time to a continuous ream of paper.
With ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Send_an_unknown_method_call | Send an unknown method call | Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| #Cach.C3.A9_ObjectScript | Caché ObjectScript | Class Unknown.Example Extends %RegisteredObject
{
Method Foo()
{
Write "This is foo", !
}
Method Bar()
{
Write "This is bar", !
}
} | Give a code snippet in #Cach.C3.A9_ObjectScript
Task
Invoke an object method where the name of the method to be invoked can be generated at run time.
Related tasks
Respond to an unknown method call.
Runtime evaluation
| 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... | #Gambas | Gambas | Public Sub Form_Open()
Dim sFile As String
sFile = File.Load(User.home &/ "file.txt")
End | Give a code snippet in #Gambas
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 incr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_common_directory_path | Find common directory path | Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the directory separator and the foll... | #Nim | Nim | import strutils
proc commonprefix(paths: openarray[string], sep = "/"): string =
if paths.len == 0: return ""
block outer:
for i in 0 ..< paths[0].len:
result = paths[0][0 .. i]
for path in paths:
if not path.startsWith(result):
break outer
result = result[0 .. result.rfind(sep... | Give a code snippet in #Nim
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the dir... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/Integer | Literals/Integer | Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should be interpreted by the compiler or... | #C.23 | C# | int a = 42;
int b = 0x2a; | Give a code snippet in #C.23
Some programming languages have ways of expressing integer literals in bases other than the normal base ten.
Task
Show how integer literals can be expressed in as many bases as your language allows.
Note: this should not involve the calling of any functions/methods, but should be ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Farey_sequence | Farey sequence | The Farey sequence Fn of order n is the sequence of completely reduced fractions between 0 and 1 which, when in lowest terms, have denominators less than or equal to n, arranged in order of increasing size.
The Farey sequence is sometimes incorrectly called a Farey series.
Each Farey se... | #Vlang | Vlang | struct Frac {
num int
den int
}
fn (f Frac) str() string {
return "$f.num/$f.den"
}
fn f(l Frac, r Frac, n int) {
m := Frac{l.num + r.num, l.den + r.den}
if m.den <= n {
f(l, m, n)
print("$m ")
f(m, r, n)
}
}
fn main() {
// task 1. solution by recursive generat... | Give a code snippet in #Vlang
The Farey sequence Fn of order n is the sequence of completely reduced fractions between 0 and 1 which, when in lowest terms, have denominators less than or equal to n, arranged in order of increasing size.
The Farey sequence is sometimes incorrectly called a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Phix | Phix | without js -- file i/o
procedure test(string filename)
string msg
switch get_file_type(filename) do
case FILETYPE_UNDEFINED: msg = "is UNDEFINED"
case FILETYPE_NOT_FOUND: msg = "is NOT_FOUND"
case FILETYPE_FILE: msg = "is a FILE"
case FILETYPE_DIRECTORY:
integer ... | Give a code snippet in #Phix
Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an emp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Identity_matrix | Identity matrix | Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
1
⋯
0
⋮
⋮
⋮
⋱
... | #Erlang | Erlang | %% Identity Matrix in Erlang for the Rosetta Code Wiki.
%% Implemented by Arjun Sunel
-module(identity_matrix).
-export([square_matrix/2 , identity/1]).
square_matrix(Size, Elements) ->
[[Elements(Column, Row) || Column <- lists:seq(1, Size)] || Row <- lists:seq(1, Size)].
identity(Size) ->
square_matrix(... | Give a code snippet in #Erlang
Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Runge-Kutta_method | Runge-Kutta method | Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equation has an exact solution:
... | #ALGOL_68 | ALGOL 68 |
BEGIN
PROC rk4 = (PROC (REAL, REAL) REAL f, REAL y, x, dx) REAL :
BEGIN CO Fourth-order Runge-Kutta method CO
REAL dy1 = dx * f(x, y);
REAL dy2 = dx * f(x + dx / 2.0, y + dy1 / 2.0);
REAL dy3 = dx * f(x + dx / 2.0, y + dy2 / 2.0);
REAL dy4 = dx * f(x + dx, y + dy3);
y + (dy1 + 2.0... | Give a code snippet in #ALGOL_68
Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar_-_for_%22REAL%22_programmers | Calendar - for "REAL" programmers | Task
Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented entirely without lowercase.
Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide.
(Hint: manually convert the code from the Calendar task to al... | #Julia | Julia |
# IF THIS SMALL FUNCTION IS PLACED IN THE STARTUP.JL
# FILE, IT WILL BE LOADED ON STARTUP. THE REST OF
# THIS EXAMPLE IS IN ALL UPPERCASE.
function RUNUPPERCASECODE(CO)
COD = replace(lowercase(CO), "date" => "Date")
for E in Meta.parse(COD, 1) eval(E) end
end
CODE = """BEGIN
USING DATES;
CENTEROBJECT(X,... | Give a code snippet in #Julia
Task
Provide an algorithm as per the Calendar task, except the entire code for the algorithm must be presented entirely without lowercase.
Also - as per many 1969 era line printers - format the calendar to nicely fill a page that is 132 characters wide.
(Hint: manually convert the co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #FutureBasic | FutureBasic | include "NSLog.incl"
long fizz, buzz, i
for i = 1 to 100
fizz = (i mod 3 )
buzz = (i mod 5 )
if fizz + buzz == 0 then NSLog(@"FizzBuzz") : continue
if fizz == 0 then NSLog(@"Fizz") : continue
if buzz == 0 then NSLog(@"Buzz") : continue
NSLog(@"%ld",i)
next i
HandleEvents | Give a code snippet in #FutureBasic
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print Fi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar | Calendar | Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with accented characters). Target fo... | #Go | Go | package main
import (
"fmt"
"time"
)
const pageWidth = 80
func main() {
printCal(1969)
}
func printCal(year int) {
thisDate := time.Date(year, 1, 1, 1, 1, 1, 1, time.UTC)
var (
dayArr [12][7][6]int // month, weekday, week
month, lastMonth time.Month
weekInMonth, dayInMonth int... | Give a code snippet in #Go
Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with acc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler%27s_sum_of_powers_conjecture | Euler's sum of powers conjecture | There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth power,
except for the trivial case... | #Common_Lisp | Common Lisp |
(ql:quickload :alexandria)
(let ((fifth-powers (mapcar #'(lambda (x) (expt x 5))
(alexandria:iota 250))))
(loop named outer for x0 from 1 to (length fifth-powers) do
(loop for x1 from 1 below x0 do
(loop for x2 from 1 below x1 do
(loop for x3 from 1 below x2 do
... | Give a code snippet in #Common_Lisp
There is a conjecture in mathematics that held for over two hundred years before it was disproved by the finding of a counterexample in 1966 by Lander and Parkin.
Euler's (disproved) sum of powers conjecture
At least k positive kth powers are required to sum to a kth p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/List_comprehensions | List comprehensions | A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and the use of map and filter functio... | #ABAP | ABAP |
CLASS lcl_pythagorean_triplet DEFINITION CREATE PUBLIC.
PUBLIC SECTION.
TYPES: BEGIN OF ty_triplet,
x TYPE i,
y TYPE i,
z TYPE i,
END OF ty_triplet,
tty_triplets TYPE STANDARD TABLE OF ty_triplet WITH NON-UNIQUE EMPTY KEY.
CLASS-METHODS:
g... | Give a code snippet in #ABAP
A list comprehension is a special syntax in some programming languages to describe lists. It is similar to the way mathematicians describe sets, with a set comprehension, hence the name.
Some attributes of a list comprehension are:
They should be distinct from (nested) for loops and the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/0-1 | Knapsack problem/0-1 | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and it will have to last the whole day.
He cre... | #PureBasic | PureBasic | Structure item
name.s
weight.i ;units are dekagrams (dag)
Value.i
EndStructure
Structure memo
Value.i
List picked.i()
EndStructure
Global itemCount = 0 ;this will be increased as needed to match count
Global Dim items.item(itemCount)
Procedure addItem(name.s, weight, Value)
If itemCount >= ArraySize(i... | Give a code snippet in #PureBasic
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and it will ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_input/output | File input/output | File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into a variable
how to write ... | #Ring | Ring |
fn1 = "ReadMe.txt"
fn2 = "ReadMe2.txt"
fp = fopen(fn1,"r")
str = fread(fp, getFileSize(fp))
fclose(fp)
fp = fopen(fn2,"w")
fwrite(fp, str)
fclose(fp)
see "OK" + nl
func getFileSize fp
c_filestart = 0
c_fileend = 2
fseek(fp,0,c_fileend)
nfilesize = ftell(fp)
fseek(fp,0,c_filestart)
... | Give a code snippet in #Ring
File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitcoin/address_validation | Bitcoin/address validation | Bitcoin/address validation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Write a program that takes a bitcoin address as argument,
and checks whether or not this address is valid.
A bitcoin address uses a base58 encoding, which uses an alphabet of th... | #Dart | Dart | import 'package:crypto/crypto.dart';
class Bitcoin {
final String ALPHABET =
"123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz";
List<int> bigIntToByteArray(BigInt data) {
String str;
bool neg = false;
if (data < BigInt.zero) {
str = (~data).toRadixString(16);
neg = true;... | Give a code snippet in #Dart
Bitcoin/address validation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Write a program that takes a bitcoin address as argument,
and checks whether or not this address is valid.
A bitcoin address uses a base58 encoding... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #MATLAB_.2F_Octave | MATLAB / Octave | d1 = dir('input.txt');
d2 = dir('/input.txt');
fprintf('Size of input.txt is %d bytes\n', d1.bytes)
fprintf('Size of /input.txt is %d bytes\n', d2.bytes) | Give a code snippet in #MATLAB_.2F_Octave
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions | First-class functions | A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other functions
Use functions as retu... | #zkl | zkl | var a=T(fcn(x){ x.toRad().sin() }, fcn(x){ x.toRad().cos() }, fcn(x){ x*x*x} );
var b=T(fcn(x){ x.asin().toDeg() }, fcn(x){ x.acos().toDeg() }, fcn(x){ x.pow(1.0/3) });
var H=Utils.Helpers;
var ab=b.zipWith(H.fcomp,a); //-->list of deferred calculations
ab.run(True,5.0); //-->L(5.0,5.0,5.0)
a.run(True,5.0) //-->... | Give a code snippet in #zkl
A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other fun... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root | Digital root | The digital root,
X
{\displaystyle X}
, of a number,
n
{\displaystyle n}
, is calculated:
find
X
{\displaystyle X}
as the sum of the digits of
n
{\displaystyle n}
find a new
X
{\displaystyle X}
by summing the digits of
X
{\displaystyle X}
, repeating until
X
{\displ... | #Julia | Julia | function digitalroot(n::Integer, bs::Integer=10)
if n < 0 || bs < 2 throw(DomainError()) end
ds, pers = n, 0
while bs ≤ ds
ds = sum(digits(ds, bs))
pers += 1
end
return pers, ds
end
for i in [627615, 39390, 588225, 393900588225, big(2) ^ 100]
pers, ds = digitalroot(i)
print... | Give a code snippet in #Julia
The digital root,
X
{\displaystyle X}
, of a number,
n
{\displaystyle n}
, is calculated:
find
X
{\displaystyle X}
as the sum of the digits of
n
{\displaystyle n}
find a new
X
{\displaystyle X}
by summing the digits of
X
{\displaystyle X}
, ... | 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
¯... | #VBA | VBA | Option Base 1
Private Function mean(s() As Variant) As Double
mean = WorksheetFunction.Average(s)
End Function
Private Function standard_deviation(s() As Variant) As Double
standard_deviation = WorksheetFunction.StDev(s)
End Function
Public Sub basic_statistics()
Dim s() As Variant
For e = 2 To 4
... | Give a code snippet in #VBA
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\,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Sidef | Sidef | func catalan(num) {
var t = [0, 1]
(1..num).map { |i|
flip(^i ).each {|j| t[j+1] += t[j] }
t[i+1] = t[i]
flip(^i.inc).each {|j| t[j+1] += t[j] }
t[i+1] - t[i]
}
}
say catalan(15).join(' ') | Give a code snippet in #Sidef
Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that gene... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Collections | Collections | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Create a collection, and add a fe... | #Lua | Lua | collection = {0, '1'}
print(collection[1]) -- prints 0
collection = {["foo"] = 0, ["bar"] = '1'} -- a collection of key/value pairs
print(collection["foo"]) -- prints 0
print(collection.foo) -- syntactic sugar, also prints 0
collection = {0, '1', ["foo"] = 0, ["bar"] = '1'} | Give a code snippet in #Lua
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Collections are abstractions to represent sets of values.
In statically-typed languages, the values are typically of a common data type.
Task
Crea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Amb | Amb | Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton").
The Amb operator takes a v... | #Phix | Phix | function amb1(sequence sets, object res=0, integer idx=1)
integer ch = 0,
pass = 0
if idx>length(sets) then
pass = 1
else
if res=0 then
res = repeat(0,length(sets))
else
res = deep_copy(res)
ch = sets[idx-1][res[idx-1]][$]
end i... | Give a code snippet in #Phix
Define and give an example of the Amb operator.
The Amb operator (short for "ambiguous") expresses nondeterminism. This doesn't refer to randomness (as in "nondeterministic universe") but is closely related to the term as it is used in automata theory ("non-deterministic finite automaton"... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magnanimous_numbers | Magnanimous numbers | A magnanimous number is an integer where there is no place in the number where a + (plus sign) could be added between any two digits to give a non-prime sum.
E.G.
6425 is a magnanimous number. 6 + 425 == 431 which is prime; 64 + 25 == 89 which is prime; 642 + 5 == 647 which is prime.
3538 is not a magnanimous numb... | #Phix | Phix | with javascript_semantics
function magnanimous(integer n)
integer p = 1, r = 0
while n>=10 do
r += remainder(n,10)*p
n = floor(n/10)
if not is_prime(n+r) then return false end if
p *= 10
end while
return true
end function
sequence mag = {}
integer n = 0
while length(ma... | Give a code snippet in #Phix
A magnanimous number is an integer where there is no place in the number where a + (plus sign) could be added between any two digits to give a non-prime sum.
E.G.
6425 is a magnanimous number. 6 + 425 == 431 which is prime; 64 + 25 == 89 which is prime; 642 + 5 == 647 which is prime.
... | 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... | #Python | Python |
#!/usr/bin/env python3
from unicodedata import name
def unicode_code(ch):
return 'U+{:04x}'.format(ord(ch))
def utf8hex(ch):
return " ".join([hex(c)[2:] for c in ch.encode('utf8')]).upper()
if __name__ == "__main__":
print('{:<11} {:<36} {:<15} {:<15}'.format('Character', 'Name', 'Unicode', 'U... | Give a code snippet in #Python
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 re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #Ol | Ol |
;;; create sample associative array
(define aa (list->ff '(
(hello . 1)
(world . 2)
(! . 3))))
(print aa)
; ==> #((! . 3) (hello . 1) (world . 2))
;;; simplest iteration over all associative array (using ff-iter, lazy iterator)
(let loop ((kv (ff-iter aa)))
(cond
((null? kv) #true)
((pair?... | Give a code snippet in #Ol
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MD4 | MD4 | Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsolete protocols.
RFC 1320 specifi... | #Julia | Julia |
using Nettle
msg = "Rosetta Code"
h = HashState(MD4)
update!(h, msg)
h = hexdigest!(h)
println("\"", msg, "\" => ", h)
| Give a code snippet in #Julia
Find the MD4 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Code” (without quotes).
You may either call an MD4 library, or implement MD4 in your language.
MD4 is an obsolete hash function that computes a 128-bit message digest that sometimes appears in obsole... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #Clipper | Clipper | Function Addsub( x, y )
Return { x+y, x-y } | Give a code snippet in #Clipper
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game | 24 game | The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. T... | #BBC_BASIC | BBC BASIC | REM Choose four random digits (1-9) with repetitions allowed:
DIM digits%(4), check%(4)
FOR choice% = 1 TO 4
digits%(choice%) = RND(9)
NEXT choice%
REM Prompt the player:
PRINT "Enter an equation (using all of, and only, the single digits ";
FOR index% = 1 TO 4
... | Give a code snippet in #BBC_BASIC
The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those fou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Arithmetic_mean | Averages/Arithmetic mean | Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin... | #Crystal | Crystal | # Crystal will return NaN if an empty array is passed
def mean(arr) : Float64
arr.sum / arr.size.to_f
end | Give a code snippet in #Crystal
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an es... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_interpolation_(included) | String interpolation (included) |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #C.2B.2B | C++ | #include <string>
#include <iostream>
int main( ) {
std::string original( "Mary had a X lamb." ) , toBeReplaced( "X" ) ,
replacement ( "little" ) ;
std::string newString = original.replace( original.find( "X" ) ,
toBeReplaced.length( ) , replacement ) ;
std::cout << "String after replacement: " << ne... | Give a code snippet in #C.2B.2B
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/Write_float_arrays_to_a_text_file | Write float arrays to a text file | Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3, 1e11};
y = {1, 1.41421356... | #R | R | writexy <- function(file, x, y, xprecision=3, yprecision=3) {
fx <- formatC(x, digits=xprecision, format="g", flag="-")
fy <- formatC(y, digits=yprecision, format="g", flag="-")
dfr <- data.frame(fx, fy)
write.table(dfr, file=file, sep="\t", row.names=F, col.names=F, quote=F)
}
x <- c(1, 2, 3, 1e11)
y <- sqrt... | Give a code snippet in #R
Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3, 1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_reversal_game | Number reversal game | Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The score is the count of the reversa... | #C | C | void number_reversal_game()
{
printf("Number Reversal Game. Type a number to flip the first n numbers.");
printf("Win by sorting the numbers in ascending order.\n");
printf("Anything besides numbers are ignored.\n");
printf("\t |1__2__3__4__5__6__7__8__9|\n");
int list[9] = {1,2,3,4,5,6,7,8,9};
... | Give a code snippet in #C
Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The score ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
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.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #Babel | Babel | main :
{ (1 2 3) foo set -- foo = (1 2 3)
4 foo push -- foo = (1 2 3 4)
0 foo unshift -- foo = (0 1 2 3 4)
foo pop -- foo = (0 1 2 3)
foo shift -- foo = (1 2 3)
check_foo
{ foo pop } 4 times -- Pops too many times, but this is OK and Babel ... | Give a code snippet in #Babel
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.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is ac... | 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... | #Rust | Rust | extern crate luhn_cc;
use luhn_cc::compute_luhn;
fn main() {
assert_eq!(validate_isin("US0378331005"), true);
assert_eq!(validate_isin("US0373831005"), false);
assert_eq!(validate_isin("U50378331005"), false);
assert_eq!(validate_isin("US03378331005"), false);
assert_eq!(validate_isin("AU0000XVG... | Give a code snippet in #Rust
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cholesky_decomposition | Cholesky decomposition | Every symmetric, positive definite matrix A can be decomposed into a product of a unique lower triangular matrix L and its transpose:
A
=
L
L
T
{\displaystyle A=LL^{T}}
L
{\displaystyle L}
is called the Cholesky factor of
A
{\displaystyle A}
, and can be interpreted as a generalized square r... | #Tcl | Tcl | proc cholesky a {
set m [llength $a]
set n [llength [lindex $a 0]]
set l [lrepeat $m [lrepeat $n 0.0]]
for {set i 0} {$i < $m} {incr i} {
for {set k 0} {$k < $i+1} {incr k} {
set sum 0.0
for {set j 0} {$j < $k} {incr j} {
set sum [expr {$sum + [lindex $l $i $j] * [lindex $l $k $j]}]
}
... | Give a code snippet in #Tcl
Every symmetric, positive definite matrix A can be decomposed into a product of a unique lower triangular matrix L and its transpose:
A
=
L
L
T
{\displaystyle A=LL^{T}}
L
{\displaystyle L}
is called the Cholesky factor of
A
{\displaystyle A}
, and can be interpre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Isqrt_(integer_square_root)_of_X | Isqrt (integer square root) of X | Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your computer programming language, assume... | #S-BASIC | S-BASIC |
comment
return integer square root of n using quadratic
residue algorithm. WARNING: the function will fail
for x > 16,383.
end
function isqrt(x = integer) = integer
var q, r, t = integer
q = 1
while q <= x do
q = q * 4 rem overflow may occur here!
r = 0
while q > 1 do
begin
q = ... | Give a code snippet in #S-BASIC
Sometimes a function is needed to find the integer square root of X, where X can be a
real non─negative number.
Often X is actually a non─negative integer.
For the purposes of this task, X can be an integer or a real number, but if it
simplifies things in your comput... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #AutoHotkey | AutoHotkey |
f(x) {
return "This " . x
}
g(x) {
return "That " . x
}
show(fun) {
msgbox % %fun%("works")
}
show(Func("f")) ; either create a Func object
show("g") ; or just name the function
return
| Give a code snippet in #AutoHotkey
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_from_two_arrays | Hash from two arrays | Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| #Factor | Factor | USING: hashtables ;
{ "one" "two" "three" } { 1 2 3 } zip >hashtable | Give a code snippet in #Factor
Task
Using two Arrays of equal length, create a Hash object
where the elements from one array (the keys) are linked
to the elements of the other (the values)
Related task
Associative arrays/Creation
| 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... | #Icon_and_Unicon | Icon and Unicon | procedure main()
every write(quibble([] | ["ABC"] | ["ABC","DEF"] | ["ABC","DEF","G","H"]))
end
procedure quibble(A)
join := s := ""
while s := pull(A)||join||s do join := if *join = 0 then " and " else ", "
return "{"||s||"}"
end | Give a code snippet in #Icon_and_Unicon
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 "{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Man_or_boy_test | Man or boy test | Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. The aim of the test was to distinguis... | #JavaScript | JavaScript | function a(k, x1, x2, x3, x4, x5) {
function b() {
k -= 1;
return a(k, b, x1, x2, x3, x4);
}
return (k > 0) ? b() : x4() + x5();
}
// this uses lambda wrappers around the numeric arguments
function x(n) {
return function () {
return n;
};
}
alert(a(10, x(1), x(-1), x(-1), x(1), x(0))); | Give a code snippet in #JavaScript
Man or boy test
You are encouraged to solve this task according to the task description, using any language you may know.
Background: The man or boy test was proposed by computer scientist Donald Knuth as a means of evaluating implementations of the ALGOL 60 programming language. T... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #Go | Go | package main
import (
"fmt"
"math"
)
func remarkable(n int) int {
return n + int(.5+math.Sqrt(float64(n)))
}
func main() {
// task 1
fmt.Println(" n r(n)")
fmt.Println("--- ---")
for n := 1; n <= 22; n++ {
fmt.Printf("%3d %3d\n", n, remarkable(n))
}
// task 2
... | Give a code snippet in #Go
Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 ... | 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... | #Icon_and_Unicon | Icon and Unicon | s := "" # null string
s := string('A'--'A') # ... converted from cset difference
s := char(0)[0:0] # ... by slicing
s1 == "" # lexical comparison, could convert s1 to string
s1 === "" # comparison won't force conversion
*s1 = 0 # zero length, howev... | Give a code snippet in #Icon_and_Unicon
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 emp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Histogram | Bitmap/Histogram | Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It must have range of at least 0..NxM, wh... | #Common_Lisp | Common Lisp | (defpackage #:histogram
(:use #:cl
#:opticl))
(in-package #:histogram)
(defun color->gray-image (image)
(check-type image 8-bit-rgb-image)
(let ((gray-image (with-image-bounds (height width) image
(make-8-bit-gray-image height width :initial-element 0))))
(do-pixels (i j) ima... | Give a code snippet in #Common_Lisp
Extend the basic bitmap storage defined on this page to support dealing with image histograms. The image histogram contains for each luminance the count of image pixels having this luminance. Choosing a histogram representation take care about the data type used for the counts. It m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Temperature_conversion | Temperature conversion | There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 kelvin.
0 kelvin is absolute z... | #EasyLang | EasyLang | k = number input
print k & " °K"
print k - 273.15 & " °C"
print k * 1.8 - 459.67 & " °F"
print k * 1.8 & " °R" | Give a code snippet in #EasyLang
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.... | christopher/rosetta-code |
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