task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Linear_congruential_generator | Linear congruential generator | The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle r_{0}}
is a seed.
r
1
... | #Python | Python | def bsd_rand(seed):
def rand():
rand.seed = (1103515245*rand.seed + 12345) & 0x7fffffff
return rand.seed
rand.seed = seed
return rand
def msvcrt_rand(seed):
def rand():
rand.seed = (214013*rand.seed + 2531011) & 0x7fffffff
return rand.seed >> 16
rand.seed = seed
return rand | Give a code snippet in #Python
The linear congruential generator is a very simple example of a random number generator.
All linear congruential generators use this formula:
r
n
+
1
=
a
×
r
n
+
c
(
mod
m
)
{\displaystyle r_{n+1}=a\times r_{n}+c{\pmod {m}}}
Where:
r
0
{\displaystyle ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Snake | Snake |
This page uses content from Wikipedia. The original article was at Snake_(video_game). The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Snake is a game where the player maneuvers a line which grows i... | #Python | Python | from __future__ import annotations
import itertools
import random
from enum import Enum
from typing import Any
from typing import Tuple
import pygame as pg
from pygame import Color
from pygame import Rect
from pygame.surface import Surface
from pygame.sprite import AbstractGroup
from pygame.sprite import ... | Give a code snippet in #Python
This page uses content from Wikipedia. The original article was at Snake_(video_game). The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Snake is a game where the playe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #Little | Little | string fruit[] = {"apples", "oranges"};
puts(length(fruit)); | Give a code snippet in #Little
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter freq... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fusc_sequence | Fusc sequence |
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definition starts with unity, not zero. Th... | #Perl | Perl | use strict;
use warnings;
use feature 'say';
sub comma { reverse ((reverse shift) =~ s/(.{3})/$1,/gr) =~ s/^,//r }
sub stern_diatomic {
my ($p,$q,$i) = (0,1,shift);
while ($i) {
if ($i & 1) { $p += $q; } else { $q += $p; }
$i >>= 1;
}
$p;
}
say "First 61 terms of the Fusc sequence:\n" . join ' ', ... | Give a code snippet in #Perl
Definitions
The fusc integer sequence is defined as:
fusc(0) = 0
fusc(1) = 1
for n>1, the nth term is defined as:
if n is even; fusc(n) = fusc(n/2)
if n is odd; fusc(n) = fusc((n-1)/2) + fusc((n+1)/2)
Note that MathWorld's definition sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mode | Averages/Mode | Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if possible. If it is not appropriat... | #UNIX_Shell | UNIX Shell | #!/bin/bash
function mode {
declare -A map
max=0
for x in "$@"; do
tmp=$((${map[$x]} + 1))
map[$x]=$tmp
((tmp > max)) && max=$tmp
done
for x in "${!map[@]}"; do
[[ ${map[$x]} == $max ]] && echo -n "$x "
done
echo
} | Give a code snippet in #UNIX_Shell
Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Equilibrium_index | Equilibrium index | An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
1
=
1
{\displaystyle A_{1}=1}
... | #VBScript | VBScript | arr = Array(-7,1,5,2,-4,3,0)
WScript.StdOut.Write equilibrium(arr,UBound(arr))
WScript.StdOut.WriteLine
Function equilibrium(arr,n)
sum = 0
leftsum = 0
'find the sum of the whole array
For i = 0 To UBound(arr)
sum = sum + arr(i)
Next
For i = 0 To UBound(arr)
sum = sum - arr(i)
If leftsum = sum Then
equ... | Give a code snippet in #VBScript
An equilibrium index of a sequence is an index into the sequence such that the sum of elements at lower indices is equal to the sum of elements at higher indices.
For example, in a sequence
A
{\displaystyle A}
:
A
0
=
−
7
{\displaystyle A_{0}=-7}
A
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #Fortran | Fortran | program happy
implicit none
integer, parameter :: find = 8
integer :: found
integer :: number
found = 0
number = 1
do
if (found == find) then
exit
end if
if (is_happy (number)) then
found = found + 1
write (*, '(i0)') number
end if
number = number + 1
end do
c... | Give a code snippet in #Fortran
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #Dragon | Dragon | i = 1024
while(i > 0){
showln i
i >>= 1 //also acceptable: i /= 2
} | Give a code snippet in #Dragon
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downwa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Textonyms | Textonyms | When entering text on a phone's digital pad it is possible that a particular combination of digits corresponds to more than one word. Such are called textonyms.
Assuming the digit keys are mapped to letters as follows:
2 -> ABC
3 -> DEF
4 -> GHI
5 -> JKL
6 -> MNO
7 -> PQRS
8 -> TUV
9 -... | #Delphi | Delphi |
program Textonyms;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.Classes,
System.Generics.Collections,
System.Character;
const
TEXTONYM_MAP = '22233344455566677778889999';
type
TextonymsChecker = class
private
Total, Elements, Textonyms, MaxFound: Integer;
MaxStrings: TList<string>;
... | Give a code snippet in #Delphi
When entering text on a phone's digital pad it is possible that a particular combination of digits corresponds to more than one word. Such are called textonyms.
Assuming the digit keys are mapped to letters as follows:
2 -> ABC
3 -> DEF
4 -> GHI
5 -> JKL
6 -> MNO
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mode | Averages/Mode | Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if possible. If it is not appropriat... | #11l | 11l | F modes(values)
DefaultDict[Int, Int] count
L(v) values
count[v]++
V best = max(count.values())
R count.filter(kv -> kv[1] == @best).map(kv -> kv[0])
print(modes([1, 3, 6, 6, 6, 6, 7, 7, 12, 12, 17]))
print(modes([1, 1, 2, 4, 4])) | Give a code snippet in #11l
Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if poss... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_word/fractal | Fibonacci word/fractal |
The Fibonacci word may be represented as a fractal as described here:
(Clicking on the above website (hal.archives-ouvertes.fr) will leave a cookie.)
For F_wordm start with F_wordCharn=1
Draw a segment forward
If current F_wordChar is 0
Turn left if n is even
Turn right if n is odd
next n and iterate until e... | #Nim | Nim | import imageman
const
Width = 1000
Height = 1000
LineColor = ColorRGBU [byte 64, 192, 96]
Output = "fibword.png"
proc fibword(n: int): string =
## Return the nth fibword.
var a = "1"
result = "0"
for _ in 1..n:
a = result & a
swap a, result
proc drawFractal(image: var Image; fw: string... | Give a code snippet in #Nim
The Fibonacci word may be represented as a fractal as described here:
(Clicking on the above website (hal.archives-ouvertes.fr) will leave a cookie.)
For F_wordm start with F_wordCharn=1
Draw a segment forward
If current F_wordChar is 0
Turn left if n is even
Turn right if n is o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Arturo | Arturo | arr: ["one" "two" "three"]
dict: #[
name: "John"
surname: "Doe"
age: 34
]
loop arr 'item ->
print item
loop dict [key val]->
print [key "=>" val] | Give a code snippet in #Arturo
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/N-smooth_numbers | N-smooth numbers | n-smooth numbers are positive integers which have no prime factors > n.
The n (when using it in the expression) n-smooth is always prime,
there are no 9-smooth numbers.
1 (unity) is always included in n-smooth numbers.
2-smooth numbers are non-negative powers of two.
5-smooth numbers are... | #C | C | #include <stdbool.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <gmp.h>
void* xmalloc(size_t n) {
void* ptr = malloc(n);
if (ptr == NULL) {
fprintf(stderr, "Out of memory\n");
exit(1);
}
return ptr;
}
void* xrealloc(void* p, size_t n) {
void* ptr = reallo... | Give a code snippet in #C
n-smooth numbers are positive integers which have no prime factors > n.
The n (when using it in the expression) n-smooth is always prime,
there are no 9-smooth numbers.
1 (unity) is always included in n-smooth numbers.
2-smooth numbers are non-negative powers of t... | 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... | #Fortran | Fortran | module mod_stack
implicit none
type node
! data entry in each node
real*8, private :: data
! pointer to the next node of the linked list
type(node), pointer, private :: next
end type node
private node
type stack
! pointer to first element of stack.
type(node), pointer, private :: f... | Give a code snippet in #Fortran
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Doubly-linked_list/Element_insertion | Doubly-linked list/Element insertion | Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element inse... | #Phix | Phix | enum NEXT,PREV,DATA
constant empty_dll = {{1,1}}
sequence dll = deep_copy(empty_dll)
procedure insert_after(object data, integer pos=1)
integer prv = dll[pos][PREV]
dll = append(dll,{pos,prv,data})
if prv!=0 then
dll[prv][NEXT] = length(dll)
end if
dll[pos][PREV] = length(dll)
end procedur... | Give a code snippet in #Phix
Doubly-Linked List (element)
This is much like inserting into a Singly-Linked List, but with added assignments so that the backwards-pointing links remain correct.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, El... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delegates | Delegates | A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern.
Objects ... | #Common_Lisp | Common Lisp | (defgeneric thing (object)
(:documentation "Thing the object."))
(defmethod thing (object)
"default implementation")
(defclass delegator ()
((delegate
:initarg :delegate
:reader delegator-delegate)))
(defmethod thing ((delegator delegator))
"If delegator has a delegate, invoke thing on the delegat... | Give a code snippet in #Common_Lisp
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Letter_frequency | Letter frequency | Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequen... | #Phix | Phix | with javascript_semantics
sequence lc = repeat(0,#7E)
--string text = get_text(command_line()[$])
string text = join(unix_dict(17))
for i=1 to length(text) do
integer ch = text[i]
if ch=-1 then exit end if
if ch>=' ' and ch<#7F then
lc[ch] += 1
end if
end for
integer count = 0
for i=' ' to #7E... | Give a code snippet in #Phix
Task
Open a text file and count the occurrences of each letter.
Some of these programs count all characters (including punctuation),
but some only count letters A to Z.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Cocktail_sort | Sorting algorithms/Cocktail 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
... | #360_Assembly | 360 Assembly | * Cocktail sort 25/06/2016
COCKTSRT CSECT
USING COCKTSRT,R13 base register
B 72(R15) skip savearea
DC 17F'0' savearea
STM R14,R12,12(R13) prolog
ST R13,4(R15) "
ST R15,8(R13) "
... | Give a code snippet in #360_Assembly
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 |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Host_introspection | Host introspection | Print the word size and endianness of the host machine.
See also: Variable size/Get
| #C | C | #include <stdio.h>
#include <stddef.h> /* for size_t */
#include <limits.h> /* for CHAR_BIT */
int main() {
int one = 1;
/*
* Best bet: size_t typically is exactly one word.
*/
printf("word size = %d bits\n", (int)(CHAR_BIT * sizeof(size_t)));
/*
* Check if the least significant bit... | Give a code snippet in #C
Print the word size and endianness of the host machine.
See also: Variable size/Get
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_seconds_to_compound_duration | Convert seconds to compound duration | Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e.g., "2 hr, 59 sec").
Demonstrat... | #Action.21 | Action! | INCLUDE "H6:REALMATH.ACT"
DEFINE PTR="CARD"
TYPE Time=[BYTE s,m,h,d,w]
CARD ARRAY units(5)
PROC Convert(REAL POINTER seconds Time POINTER t)
BYTE ARRAY b,duration=[60 60 24 7]
BYTE i
REAL r,n
b=t
FOR i=0 TO 3
DO
IntToReal(duration(i),n)
RealMod(seconds,n,r)
b(i)=RealToInt(r)
RealDivInt... | Give a code snippet in #Action.21
Task
Write a function or program which:
takes a positive integer representing a duration in seconds as input (e.g., 100), and
returns a string which shows the same duration decomposed into:
weeks,
days,
hours,
minutes, and
seconds.
This is detailed below (e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_intersection_of_two_lines | Find the intersection of two lines | [1]
Task
Find the point of intersection of two lines in 2D.
The 1st line passes though (4,0) and (6,10) .
The 2nd line passes though (0,3) and (10,7) .
| #Python | Python | def line_intersect(Ax1, Ay1, Ax2, Ay2, Bx1, By1, Bx2, By2):
""" returns a (x, y) tuple or None if there is no intersection """
d = (By2 - By1) * (Ax2 - Ax1) - (Bx2 - Bx1) * (Ay2 - Ay1)
if d:
uA = ((Bx2 - Bx1) * (Ay1 - By1) - (By2 - By1) * (Ax1 - Bx1)) / d
uB = ((Ax2 - Ax1) * (Ay1 - By1) - (A... | Give a code snippet in #Python
[1]
Task
Find the point of intersection of two lines in 2D.
The 1st line passes though (4,0) and (6,10) .
The 2nd line passes though (0,3) and (10,7) .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Align_columns | Align columns | Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
justified, right justified, o... | #AWK | AWK |
# syntax: GAWK -f ALIGN_COLUMNS.AWK ALIGN_COLUMNS.TXT
BEGIN {
colsep = " " # separator between columns
report("raw data")
}
{ printf("%s\n",$0)
arr[NR] = $0
n = split($0,tmp_arr,"$")
for (j=1; j<=n; j++) {
width = max(width,length(tmp_arr[j]))
}
}
END {
report("left justified")
... | Give a code snippet in #AWK
Given a text file of many lines, where fields within a line
are delineated by a single 'dollar' character, write a program
that aligns each column of fields by ensuring that words in each
column are separated by at least one space.
Further, allow for each word in a column to be either left
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/The_Twelve_Days_of_Christmas | The Twelve Days of Christmas | Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:
Metrics
Array length
Stri... | #AWK | AWK |
# syntax: GAWK -f THE_TWELVE_DAYS_OF_CHRISTMAS.AWK
BEGIN {
gifts[++i] = "a partridge in a pear tree."
gifts[++i] = "two turtle doves, and"
gifts[++i] = "three french hens,"
gifts[++i] = "four calling birds,"
gifts[++i] = "five golden rings,"
gifts[++i] = "six geese a-laying,"
gifts[++i] = ... | Give a code snippet in #AWK
Task
Write a program that outputs the lyrics of the Christmas carol The Twelve Days of Christmas.
The lyrics can be found here.
(You must reproduce the words in the correct order, but case, format, and punctuation are left to your discretion.)
Other tasks related to string operations:... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_a_system_command | Execute a system command | Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| #ALGOL_68 | ALGOL 68 | system("ls") | Give a code snippet in #ALGOL_68
Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Negative_base_numbers | Negative base numbers | Negative base numbers are an alternate way to encode numbers without the need for a minus sign. Various negative bases may be used including negadecimal (base -10), negabinary (-2) and negaternary (-3).[1][2]
Task
Encode the decimal number 10 as negabinary (expect 11110)
Encode the decimal number 146 as negaternary... | #Racket | Racket | #lang racket
(define all-digits (string->list "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz-"))
(define d->i-map (for/hash ((i (in-naturals)) (d all-digits)) (values d i)))
(define max-base (length all-digits))
(define (q/r n d)
(let-values (((q r) (quotient/remainder n d)))
(if (negativ... | Give a code snippet in #Racket
Negative base numbers are an alternate way to encode numbers without the need for a minus sign. Various negative bases may be used including negadecimal (base -10), negabinary (-2) and negaternary (-3).[1][2]
Task
Encode the decimal number 10 as negabinary (expect 11110)
Encode the d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #Vlang | Vlang | fn happy(h int) bool {
mut m := map[int]bool{}
mut n := h
for n > 1 {
m[n] = true
mut x := 0
for x, n = n, 0; x > 0; x /= 10 {
d := x % 10
n += d * d
}
if m[n] {
return false
}
}
return true
}
fn main() {
for f... | Give a code snippet in #Vlang
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Four_is_magic | Four is magic | Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count of characters that made up the firs... | #AutoHotkey | AutoHotkey | Four_is_magic(num){
nubmer := num
while (num <> 4)
result .= (res := spell(num)) " is " spell(num := StrLen(res)) ", "
return PrettyNumber(nubmer) " " result "four is magic!"
}
Spell(n) { ; recursive function to spell out the name of a max 36 digit integer, after leading 0s removed
Static p1=" thousand ",p2=" mi... | Give a code snippet in #AutoHotkey
Task
Write a subroutine, function, whatever it may be called in your language, that takes an integer number and returns an English text sequence starting with the English cardinal representation of that integer, the word 'is' and then the English cardinal representation of the count... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Include_a_file | Include a file | Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| #Maple | Maple | $include <somefile> | Give a code snippet in #Maple
Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Parsing/Shunting-yard_algorithm | Parsing/Shunting-yard algorithm | Task
Given the operator characteristics and input from the Shunting-yard algorithm page and tables, use the algorithm to show the changes in the operator stack and RPN output
as each individual token is processed.
Assume an input of a correct, space separated, string of tokens representing an infix expression
Gener... | #Tcl | Tcl | package require Tcl 8.5
# Helpers
proc tokenize {str} {
regexp -all -inline {[\d.]+|[-*^+/()]} $str
}
proc precedence op {
dict get {^ 4 * 3 / 3 + 2 - 2} $op
}
proc associativity op {
if {$op eq "^"} {return "right"} else {return "left"}
}
proc shunting {expression} {
set stack {}
foreach token ... | Give a code snippet in #Tcl
Task
Given the operator characteristics and input from the Shunting-yard algorithm page and tables, use the algorithm to show the changes in the operator stack and RPN output
as each individual token is processed.
Assume an input of a correct, space separated, string of tokens representi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #NSIS | NSIS |
Function IntergerComparison
Push $0
Push $1
StrCpy $0 8
StrCpy $1 2
IntCmp $0 $1 Equal Val1Less Val1More
Equal:
DetailPrint "$0 = $1"
Goto End
Val1Less:
DetailPrint "$0 < $1"
Goto End
Val1More:
DetailPrint "$0 > $1"
Goto End
End:
Pop $1
Pop $0
FunctionEnd
| Give a code snippet in #NSIS
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
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Topological_sort | Topological 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
... | #REXX | REXX | /*REXX pgm does a topological sort (orders such that no item precedes a dependent item).*/
iDep.= 0; iPos.= 0; iOrd.= 0 /*initialize some stemmed arrays to 0.*/
nL= 15; nd= 44; nc= 69 /* " " "parms" and indices.*/
label= 'DES_SYSTEM_LIB DW01 DW02 DW03 ... | Give a code snippet in #REXX
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 sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Shoelace_formula_for_polygonal_area | Shoelace formula for polygonal area | Given the n + 1 vertices x[0], y[0] .. x[N], y[N] of a simple polygon described in a clockwise direction, then the polygon's area can be calculated by:
abs( (sum(x[0]*y[1] + ... x[n-1]*y[n]) + x[N]*y[0]) -
(sum(x[1]*y[0] + ... x[n]*y[n-1]) + x[0]*y[N])
) / 2
(Where abs returns the absolute value)
Task
Write ... | #Visual_Basic_.NET | Visual Basic .NET | Option Strict On
Imports Point = System.Tuple(Of Double, Double)
Module Module1
Function ShoelaceArea(v As List(Of Point)) As Double
Dim n = v.Count
Dim a = 0.0
For i = 0 To n - 2
a += v(i).Item1 * v(i + 1).Item2 - v(i + 1).Item1 * v(i).Item2
Next
Return Mat... | Give a code snippet in #Visual_Basic_.NET
Given the n + 1 vertices x[0], y[0] .. x[N], y[N] of a simple polygon described in a clockwise direction, then the polygon's area can be calculated by:
abs( (sum(x[0]*y[1] + ... x[n-1]*y[n]) + x[N]*y[0]) -
(sum(x[1]*y[0] + ... x[n]*y[n-1]) + x[0]*y[N])
) / 2
(Where ab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #Aime | Aime | real
Invsqr(real n)
{
1 / (n * n);
}
integer
main(void)
{
integer i;
real sum;
sum = 0;
i = 1;
while (i < 1000) {
sum += Invsqr(i);
i += 1;
}
o_real(14, sum);
o_byte('\n');
0;
} | Give a code snippet in #Aime
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Compiler/virtual_machine_interpreter | Compiler/virtual machine interpreter | A virtual machine implements a computer in software.
Task[edit]
Write a virtual machine interpreter. This interpreter should be able to run virtual
assembly language programs created via the task. This is a
byte-coded, 32-bit word stack based virtual machine.
The program should read input from a file and/or stdin, an... | #Phix | Phix | --
-- demo\rosetta\Compiler\vm.exw
-- ============================
--
-- Since we have generated executable machine code, the virtual machine, such as it is, is just
-- the higher level implementations of printc/i/s, see setbuiltins() in cgen.e
-- Otherwise the only difference between this and cgen.exw is call(code... | Give a code snippet in #Phix
A virtual machine implements a computer in software.
Task[edit]
Write a virtual machine interpreter. This interpreter should be able to run virtual
assembly language programs created via the task. This is a
byte-coded, 32-bit word stack based virtual machine.
The program should read inpu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Leonardo_numbers | Leonardo numbers |
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) = L(n-1) + L(n-2) + 1 ... | #Vlang | Vlang | fn leonardo(n int, l0 int, l1 int, add int) []int {
mut leo := []int{len: n}
leo[0] = l0
leo[1] = l1
for i := 2; i < n; i++ {
leo[i] = leo[i - 1] + leo[i - 2] + add
}
return leo
}
fn main() {
println("The first 25 Leonardo numbers with L[0] = 1, L[1] = 1 and add number = 1 are:")
... | Give a code snippet in #Vlang
Leonardo numbers are also known as the Leonardo series.
The Leonardo numbers are a sequence of numbers defined by:
L(0) = 1 [1st equation]
L(1) = 1 [2nd equation]
L(n) =... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Pop11 | Pop11 | define mean(v);
lvars n = length(v), i, s = 0;
if n = 0 then
return(0);
else
for i from 1 to n do
s + v(i) -> s;
endfor;
endif;
return(s/n);
enddefine; | Give a code snippet in #Pop11
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 esta... | 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... | #jq | jq | # Search for y in 1 .. maxn (inclusive) for a solution to SIGMA (xi ^ 5) = y^5
# and for each solution with x0<=x1<=...<x3, print [x0, x1, x3, x3, y]
#
def sum_of_powers_conjecture(maxn):
def p5: . as $in | (.*.) | ((.*.) * $in);
def fifth: log / 5 | exp;
# return the fifth root if . is a power of 5
def integ... | Give a code snippet in #jq
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,
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_in_octal | Count in octal | Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reached.
Related task
Integer sequ... | #F.23 | F# | let rec countInOctal num : unit =
printfn "%o" num
countInOctal (num + 1)
countInOctal 1 | Give a code snippet in #F.23
Task
Produce a sequential count in octal, starting at zero, and using an increment of a one for each consecutive number.
Each number should appear on a single line, and the program should count until terminated, or until the maximum value of the numeric type in use is reached.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function... | #C.23 | C# | using System;
class Program {
static void Main(string[] args) {
PrintAll("test", "rosetta code", 123, 5.6);
}
static void PrintAll(params object[] varargs) {
foreach (var i in varargs) {
Console.WriteLine(i);
}
}
} | Give a code snippet in #C.23
Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Re... | 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... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "time.s7i";
const proc: main is func
begin
writeln(time.value);
end func; | Give a code snippet in #Seed7
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 s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_occurrences_of_a_substring | Count occurrences of a substring | Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
It should return an integer cou... | #Go | Go | package main
import (
"fmt"
"strings"
)
func main() {
fmt.Println(strings.Count("the three truths", "th")) // says: 3
fmt.Println(strings.Count("ababababab", "abab")) // says: 2
} | Give a code snippet in #Go
Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
It ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_variable_names | Unicode variable names | Task
Describe, and give a pointer to documentation on your languages use of characters beyond those of the ASCII character set in the naming of variables.
Show how to:
Set a variable with a name including the 'Δ', (delta character), to 1
Increment it
Print its value.
Related task
Case-sensitivity of identif... | #Emacs_Lisp | Emacs Lisp | (setq Δ 1)
(setq Δ (1+ Δ))
(message "Δ is %d" Δ) | Give a code snippet in #Emacs_Lisp
Task
Describe, and give a pointer to documentation on your languages use of characters beyond those of the ASCII character set in the naming of variables.
Show how to:
Set a variable with a name including the 'Δ', (delta character), to 1
Increment it
Print its value.
Related... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Bresenham%27s_line_algorithm | Bitmap/Bresenham's line algorithm | Task
Using the data storage type defined on the Bitmap page for raster graphics images,
draw a line given two points with Bresenham's line algorithm.
| #BBC_BASIC | BBC BASIC | Width% = 200
Height% = 200
REM Set window size:
VDU 23,22,Width%;Height%;8,16,16,128
REM Draw lines:
PROCbresenham(50,100,100,190,0,0,0)
PROCbresenham(100,190,150,100,0,0,0)
PROCbresenham(150,100,100,10,0,0,0)
PROCbresenham(100,10,50,100,0,0,0)
END
... | Give a code snippet in #BBC_BASIC
Task
Using the data storage type defined on the Bitmap page for raster graphics images,
draw a line given two points with Bresenham's line algorithm.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Check_output_device_is_a_terminal | Check output device is a terminal | Task
Demonstrate how to check whether the output device is a terminal or not.
Related task
Check input device is a terminal
| #Haskell | Haskell | module Main where
-- requires the unix package
-- https://hackage.haskell.org/package/unix
import System.Posix.Terminal (queryTerminal)
import System.Posix.IO (stdOutput)
main :: IO ()
main = do
istty <- queryTerminal stdOutput
putStrLn
(if istty
then "stdout is tty"
else "stdout is not tty") | Give a code snippet in #Haskell
Task
Demonstrate how to check whether the output device is a terminal or not.
Related task
Check input device is a terminal
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitwise_operations | Bitwise operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Swift | Swift | func bitwise(a: Int, b: Int) {
// All bitwise operations (including shifts)
// require both operands to be the same type
println("a AND b: \(a & b)")
println("a OR b: \(a | b)")
println("a XOR b: \(a ^ b)")
println("NOT a: \(~a)")
println("a << b: \(a << b)") // left shift
// for right shifts, if the op... | Give a code snippet in #Swift
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncate_a_file | Truncate a file | Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating a temporary file of a reduced... | #C.23 | C# | using System;
using System.IO;
namespace TruncateFile
{
internal class Program
{
private static void Main(string[] args)
{
TruncateFile(args[0], long.Parse(args[1]));
}
private static void TruncateFile(string path, long length)
{
if (!File.Exis... | Give a code snippet in #C.23
Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/1 | Text processing/1 | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. In these situations another pr... | #Aime | Aime | integer bads, count, max_bads;
file f;
list l;
real s;
text bad_day, worst_day;
f.stdin;
max_bads = count = bads = s = 0;
while (f.list(l, 0) ^ -1) {
integer i;
i = 2;
while (i < 49) {
if (0 < atoi(l[i])) {
count += 1;
s += atof(l[i - 1]);
if (max_bads < b... | Give a code snippet in #Aime
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
Often data is produced by one program, in the wrong format for later use by another program or person. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/N%27th | N'th | Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix.
Example
Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th
Task
Use your routine to show here the output for at least t... | #AppleScript | AppleScript | -- ORDINAL STRINGS -----------------------------------------------------------
-- ordinalString :: Int -> String
on ordinalString(n)
(n as string) & ordinalSuffix(n)
end ordinalString
-- ordinalSuffix :: Int -> String
on ordinalSuffix(n)
set modHundred to n mod 100
if (11 ≤ modHundred) and (13 ≥ modHund... | Give a code snippet in #AppleScript
Write a function/method/subroutine/... that when given an integer greater than or equal to zero returns a string of the number followed by an apostrophe then the ordinal suffix.
Example
Returns would include 1'st 2'nd 3'rd 11'th 111'th 1001'st 1012'th
Task
Use your routine t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strong_and_weak_primes | Strong and weak primes |
Definitions (as per number theory)
The prime(p) is the pth prime.
prime(1) is 2
prime(4) is 7
A strong prime is when prime(p) is > [prime(p-1) + prime(p+1)] ÷ 2
A weak prime is when prime(p) is < [prime(p-1) + prime(p+1)] ÷ 2
Note that the defin... | #Haskell | Haskell | import Text.Printf (printf)
import Data.Numbers.Primes (primes)
xPrimes :: (Real a, Fractional b) => (b -> b -> Bool) -> [a] -> [a]
xPrimes op ps@(p1:p2:p3:xs)
| realToFrac p2 `op` (realToFrac (p1 + p3) / 2) = p2 : xPrimes op (tail ps)
| otherwise = xPrimes op (tail ps)
main :: IO ()
main = do
printf "First ... | Give a code snippet in #Haskell
Definitions (as per number theory)
The prime(p) is the pth prime.
prime(1) is 2
prime(4) is 7
A strong prime is when prime(p) is > [prime(p-1) + prime(p+1)] ÷ 2
A weak prime is when prime(p) is < [prime(p-1) + prim... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | #NewLisp | NewLisp |
;;; No built-in big integer exponentiation
(define (exp-big x n)
(setq x (bigint x))
(let (y 1L)
(if (= n 0)
1L
(while (> n 1)
(if (odd? n)
(setq y (* x y)))
(setq x (* x x) n (/ n 2)))
(* x y))))
;
;;; task
(define (test)
(local (res)
; drop the "L" at the end
(setq res (0 (- (length re... | Give a code snippet in #NewLisp
Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gamma_function | Gamma function | Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/library function.
The Gamma funct... | #Ruby | Ruby | $a = [ 1.00000_00000_00000_00000, 0.57721_56649_01532_86061, -0.65587_80715_20253_88108,
-0.04200_26350_34095_23553, 0.16653_86113_82291_48950, -0.04219_77345_55544_33675,
-0.00962_19715_27876_97356, 0.00721_89432_46663_09954, -0.00116_51675_91859_06511,
-0.00021_52416_74114_95097, 0.00012_80502_8... | Give a code snippet in #Ruby
Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/libr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Undefined_values | Undefined values | #Pike | Pike |
> zero_type(UNDEFINED);
Result: 1
> mapping bar = ([ "foo":"hello" ]);
> zero_type(bar->foo);
Result: 0
> zero_type(bar->baz);
Result: 1
> bar->baz=UNDEFINED;
Result: 0
> zero_type(bar->baz);
Result: 0
| Give a code snippet in #Pike
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #MUMPS | MUMPS | doors new door,pass
For door=1:1:100 Set door(door)=0
For pass=1:1:100 For door=pass:pass:100 Set door(door)='door(door)
For door=1:1:100 If door(door) Write !,"Door",$j(door,4)," is open"
Write !,"All other doors are closed."
Quit
Do doors
Door 1 is open
Door 4 is open
Door 9 is open
Door 16 is open
Door ... | Give a code snippet in #MUMPS
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ..... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rate_counter | Rate counter | Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplish these goals:
Run N seconds worth... | #BaCon | BaCon | ' Rate counter
FOR i = 1 TO 3
GOSUB timeit
NEXT
i = 2000
GOSUB timeit
END
LABEL timeit
iter = 0
starter = TIMER
WHILE TRUE DO
INCR iter
IF TIMER >= starter + i THEN BREAK
WEND
PRINT iter, " iterations in ", i, " millisecond", IIF$(i > 1, "s", "")
RETURN | Give a code snippet in #BaCon
Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplish the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ackermann_function | Ackermann function | The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
n
+
1
if
m
=
0
A
(
m
... | #Elixir | Elixir | defmodule Ackermann do
def ack(0, n), do: n + 1
def ack(m, 0), do: ack(m - 1, 1)
def ack(m, n), do: ack(m - 1, ack(m, n - 1))
end
Enum.each(0..3, fn m ->
IO.puts Enum.map_join(0..6, " ", fn n -> Ackermann.ack(m, n) end)
end) | Give a code snippet in #Elixir
The Ackermann function is a classic example of a recursive function, notable especially because it is not a primitive recursive function. It grows very quickly in value, as does the size of its call tree.
The Ackermann function is usually defined as follows:
A
(
m
,
n
)
=
{
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #XPL0 | XPL0 | string 0;
char Side1, Side2;
def Size = 20;
char Avail(Size);
func CanMakeWord(Word); \returns 'true' if blocks can make Word
char Word;
int I, Let;
[Let:= Word(0) & $5F; \get letter and make sure it's uppercase
if Let = 0 then return true; \if 0 then end of word; return successful
for I:= 0 ... | Give a code snippet in #XPL0
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Break | Loops/Break | Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the loop.
If the number 10 is never gener... | #ColdFusion | ColdFusion |
<Cfset randNum = 0>
<cfloop condition="randNum neq 10">
<Cfset randNum = RandRange(0, 19)>
<Cfoutput>#randNum#</Cfoutput>
<Cfif randNum eq 10><cfbreak></Cfif>
<Cfoutput>#RandRange(0, 19)#</Cfoutput>
<Br>
</cfloop>
| Give a code snippet in #ColdFusion
Task
Show a loop which prints random numbers (each number newly generated each loop) from 0 to 19 (inclusive).
If a number is 10, stop the loop after printing it, and do not generate any further numbers.
Otherwise, generate and print a second random number before restarting the lo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_int_from_concatenated_ints | Largest int from concatenated ints | Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1, 34, 3, 98, 9, 76, 45, 4}
{54,... | #BBC_BASIC | BBC BASIC | DIM Nums%(10)
Nums%()=1,34,3,98,9,76,45,4
PRINT FNlargestint(8)
Nums%()=54,546,548,60
PRINT FNlargestint(4)
END
DEF FNlargestint(len%)
LOCAL i%,l$,a$,b$,sorted%
REPEAT
sorted%=TRUE
FOR i%=0 TO len%-2
a$=STR$Nums%(i%)
b$=STR$Nums... | Give a code snippet in #BBC_BASIC
Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{... | 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 ... | #M4 | M4 | define(`fibo',`ifelse(0,$1,0,`ifelse(1,$1,1,
`eval(fibo(decr($1)) + fibo(decr(decr($1))))')')')dnl
define(`loop',`ifelse($1,$2,,`$3($1) loop(incr($1),$2,`$3')')')dnl
loop(0,15,`fibo') | Give a code snippet in #M4
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 ge... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Guess_the_number/With_feedback_(player) | Guess the number/With feedback (player) | Task
Write a player for the game that follows the following rules:
The scorer will choose a number between set limits. The computer player will print a guess of the target number. The computer asks for a score of whether its guess is higher than, lower than, or equal to the target. The computer guesses, and the score... | #Icon_and_Unicon | Icon and Unicon |
procedure main ()
lower_limit := 1
higher_limit := 100
write ("Think of a number between 1 and 100")
write ("Press 'enter' when ready")
read ()
repeat {
if (higher_limit < lower_limit)
then { # check that player is not cheating!
write ("Something has gone wrong ... I give up")
... | Give a code snippet in #Icon_and_Unicon
Task
Write a player for the game that follows the following rules:
The scorer will choose a number between set limits. The computer player will print a guess of the target number. The computer asks for a score of whether its guess is higher than, lower than, or equal to the ta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Percolation/Bond_percolation | Percolation/Bond percolation |
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean cluster density
Given an
M
×
N... | #Phix | Phix | with javascript_semantics
constant w = 10, h = 10
sequence wall = join(repeat("+",w+1),"---")&"\n",
cell = join(repeat("|",w+1)," ")&"\n",
grid
procedure new_grid(atom p)
grid = split(join(repeat(wall,h+1),cell),'\n')
-- now knock down some walls
for i=1 to length(grid)-1 do
... | Give a code snippet in #Phix
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean clust... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #SQL | SQL | -- Setup a table with some integers
CREATE TABLE ints(INT INTEGER);
INSERT INTO ints VALUES (-1);
INSERT INTO ints VALUES (0);
INSERT INTO ints VALUES (1);
INSERT INTO ints VALUES (2);
-- Are they even or odd?
SELECT
INT,
CASE MOD(INT, 2) WHEN 0 THEN 'Even' ELSE 'Odd' END
FROM
ints; | Give a code snippet in #SQL
Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #Eiffel | Eiffel |
class
APPLICATION
create
make
feature {NONE} -- Initialization
make
-- Run application.
local
l_val: INTEGER
do
from
l_val := 1
until
l_val > 100
loop
if is_happy_number (l_val) then
print (l_val.out)
print ("%N")
end
l_val := l_val + 1
end
end
feature ... | Give a code snippet in #Eiffel
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jaro-Winkler_distance | Jaro-Winkler distance | The Jaro-Winkler distance is a metric for measuring the edit distance between words.
It is similar to the more basic Levenstein distance but the Jaro distance also accounts
for transpositions between letters in the words. With the Winkler modification to the Jaro
metric, the Jaro-Winkler distance also adds an increase ... | #Rust | Rust | use std::fs::File;
use std::io::{self, BufRead};
fn load_dictionary(filename: &str) -> std::io::Result<Vec<String>> {
let file = File::open(filename)?;
let mut dict = Vec::new();
for line in io::BufReader::new(file).lines() {
dict.push(line?);
}
Ok(dict)
}
fn jaro_winkler_distance(string... | Give a code snippet in #Rust
The Jaro-Winkler distance is a metric for measuring the edit distance between words.
It is similar to the more basic Levenstein distance but the Jaro distance also accounts
for transpositions between letters in the words. With the Winkler modification to the Jaro
metric, the Jaro-Winkler d... | 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... | #Clojure | Clojure | (defn gcd
[a b]
(if (zero? b)
a
(recur b, (mod a b))))
(defn lcm
[a b]
(/ (* a b) (gcd a b)))
;; to calculate the lcm for a variable number of arguments
(defn lcmv [& v] (reduce lcm v))
| Give a code snippet in #Clojure
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 h... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ascending_primes | Ascending primes | Generate and show all primes with strictly ascending decimal digits.
Aside: Try solving without peeking at existing solutions. I had a weird idea for generating
a prime sieve faster, which needless to say didn't pan out. The solution may be p(r)etty trivial
but generating them quickly is at least mildly interesting.
T... | #F.23 | F# |
// Ascending primes. Nigel Galloway: April 19th., 2022
[2;3;5;7]::List.unfold(fun(n,i)->match n with []->None |_->let n=n|>List.map(fun(n,g)->[for n in n.. -1..1->(n-1,i*n+g)])|>List.concat in Some(n|>List.choose(fun(_,n)->if isPrime n then Some n else None),(n|>List.filter(fst>>(<)0),i*10)))([(2,3);(6,7);(8,9)],10)
... | Give a code snippet in #F.23
Generate and show all primes with strictly ascending decimal digits.
Aside: Try solving without peeking at existing solutions. I had a weird idea for generating
a prime sieve faster, which needless to say didn't pan out. The solution may be p(r)etty trivial
but generating them quickly is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Rational | Arithmetic/Rational | Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denominator (as per a rational number).
Fur... | #Common_Lisp | Common Lisp | (loop for candidate from 2 below (expt 2 19)
for sum = (+ (/ candidate)
(loop for factor from 2 to (isqrt candidate)
when (zerop (mod candidate factor))
sum (+ (/ factor) (/ (floor candidate factor)))))
when (= sum 1)
collect can... | Give a code snippet in #Common_Lisp
Task
Create a reasonably complete implementation of rational arithmetic in the particular language using the idioms of the language.
Example
Define a new type called frac with binary operator "//" of two integers that returns a structure made up of the numerator and the denomin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_int_from_concatenated_ints | Largest int from concatenated ints | Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1, 34, 3, 98, 9, 76, 45, 4}
{54,... | #Fortran | Fortran | SUBROUTINE SWAP(A,B) !Why can't the compiler supply these!
INTEGER A,B,T
T = B
B = A
A = T
END
SUBROUTINE BIGUP(TEXT,N) !Outputs the numbers in TEXT to give the biggest number.
CHARACTER*(*) TEXT(*) !The numbers as text, aligned left.
INTEGER N !The numb... | Give a code snippet in #Fortran
Task
Given a set of positive integers, write a function to order the integers in such a way that the concatenation of the numbers forms the largest possible integer and return this integer.
Use the following two sets of integers as tests and show your program output here.
{1,... | 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
| #Go | Go | package main
import "fmt"
func main() {
keys := []string{"a", "b", "c"}
vals := []int{1, 2, 3}
hash := map[string]int{}
for i, key := range keys {
hash[key] = vals[i]
}
fmt.Println(hash)
} | Give a code snippet in #Go
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/Sum_multiples_of_3_and_5 | Sum multiples of 3 and 5 | Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| #R | R | m35 = function(n) sum(unique(c(
seq(3, n-1, by = 3), seq(5, n-1, by = 5))))
m35(1000) # 233168 | Give a code snippet in #R
Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Define_a_primitive_data_type | Define a primitive data type | Demonstrate how to define a type that behaves like an integer but has a lowest valid value of 1 and a highest valid value of 10. Include all bounds checking you need to write, or explain how the compiler or interpreter creates those bounds checks for you.
| #QBasic | QBasic |
TYPE TipoUsuario
nombre AS STRING * 15
apellido AS STRING * 30
edad AS INTEGER
END TYPE
DIM usuario(1 TO 20) AS TipoUsuario
usuario(1).nombre = "Juan"
usuario(1).apellido = "Hdez."
usuario(1).edad = 49
PRINT usuario(1).nombre, usuario(1).apellido, usuario(1).edad
| Give a code snippet in #QBasic
Demonstrate how to define a type that behaves like an integer but has a lowest valid value of 1 and a highest valid value of 10. Include all bounds checking you need to write, or explain how the compiler or interpreter creates those bounds checks for you.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Stirling_numbers_of_the_first_kind | Stirling numbers of the first kind | Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of the first kind express coeffici... | #Nim | Nim | import sequtils, strutils
proc s1(n, k: Natural): Natural =
if k == 0: return ord(n == 0)
if k > n: return 0
s1(n - 1, k - 1) + (n - 1) * s1(n - 1, k)
echo " k ", toSeq(0..12).mapIt(($it).align(2)).join(" ")
echo " n"
for n in 0..12:
stdout.write ($n).align(2)
for k in 0..n:
stdout.write... | Give a code snippet in #Nim
Stirling numbers of the first kind, or Stirling cycle numbers, count permutations according to their number
of cycles (counting fixed points as cycles of length one).
They may be defined directly to be the number of permutations of n
elements with k disjoint cycles.
Stirling numbers of th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Logical_operations | Logical operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #ACL2 | ACL2 | (defun logical-ops (a b)
(progn$ (cw "(and a b) = ~x0~%" (and a b))
(cw "(or a b) = ~x0~%" (or a b))
(cw "(not a) = ~x0~%" (not a)))) | Give a code snippet in #ACL2
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
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Secure_temporary_file | Secure temporary file | Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" criteria).
The function shou... | #Phix | Phix | without js -- (file i/o)
pp(temp_file())
{integer fn, string name} = temp_file("myapp/tmp","data","log","wb")
pp({fn,name})
close(fn)
{} = delete_file(name)
| Give a code snippet in #Phix
Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions"... | 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... | #Perl | Perl | my %scale = (
Celcius => { factor => 1 , offset => -273.15 },
Rankine => { factor => 1.8, offset => 0 },
Fahrenheit => { factor => 1.8, offset => -459.67 },
);
print "Enter a temperature in Kelvin: ";
chomp(my $kelvin = <STDIN>);
die "No such temperature!\n" unless $kelvin > 0;
foreach (sor... | Give a code snippet in #Perl
There are quite a number of temperature scales. For this task we will concentrate on four of the perhaps best-known ones:
Kelvin, Celsius, Fahrenheit, and Rankine.
The Celsius and Kelvin scales have the same magnitude, but different null points.
0 degrees Celsius corresponds to 273.15 k... | christopher/rosetta-code | |
http://rosettacode.org/wiki/General_FizzBuzz | General FizzBuzz | Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along with the corresponding word to be ... | #Racket | Racket | #lang racket/base
(define (get-matches num factors/words)
(for*/list ([factor/word (in-list factors/words)]
[factor (in-value (car factor/word))]
[word (in-value (cadr factor/word))]
#:when (zero? (remainder num factor)))
word))
(define (gen-fizzbuzz from to factors/... | Give a code snippet in #Racket
Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along wi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_the_epoch | Show the epoch | Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scenes by the implementers), b... | #PureBasic | PureBasic | If OpenConsole()
PrintN(FormatDate("Y = %yyyy M = %mm D = %dd, %hh:%ii:%ss", 0))
Print(#CRLF$ + #CRLF$ + "Press ENTER to exit"): Input()
CloseConsole()
EndIf | Give a code snippet in #PureBasic
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/Hello_world/Graphical | Hello world/Graphical |
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| #Batch_File | Batch File | @echo off
::Output to message box [Does not work in Window 7 and later]
msg * "Goodbye, World!" 2>nul
::Using MSHTA.EXE Hack::
@mshta javascript:alert("Goodbye, World!");code(close());
@mshta vbscript:Execute("msgbox(""Goodbye, World!""):code close")
pause | Give a code snippet in #Batch_File
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| 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... | #Pascal | Pascal | perl -n -0777 -e 'print "file len: ".length' stuff.txt | Give a code snippet in #Pascal
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/Copy_a_string | Copy a string | This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
W... | #Oberon-2 | Oberon-2 | MODULE CopyString;
TYPE
String = ARRAY 128 OF CHAR;
VAR
a,b: String;
BEGIN
a := "plain string";
COPY(a,b);
END CopyString. | Give a code snippet in #Oberon-2
This task is about copying a string.
Task
Where it is relevant, distinguish between copying the contents of a string
versus making an additional reference to an existing string.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empt... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horner%27s_rule_for_polynomial_evaluation | Horner's rule for polynomial evaluation | A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{\displaystyle ((((0)x+6)x+(-4))x... | #MATLAB | MATLAB | function accumulator = hornersRule(x,coefficients)
accumulator = 0;
for i = (numel(coefficients):-1:1)
accumulator = (accumulator * x) + coefficients(i);
end
end | Give a code snippet in #MATLAB
A fast scheme for evaluating a polynomial such as:
−
19
+
7
x
−
4
x
2
+
6
x
3
{\displaystyle -19+7x-4x^{2}+6x^{3}\,}
when
x
=
3
{\displaystyle x=3\;}
.
is to arrange the computation as follows:
(
(
(
(
0
)
x
+
6
)
x
+
(
−
4
)
)
x
+
7
)
x
+
(
−
19
)
{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #R | R | > epoch <- 0
> class(epoch) <- class(Sys.time())
> format(epoch, "%Y-%m-%d %H:%M:%S %Z")
[1] "1970-01-01 00:00:00 UTC" | Give a code snippet in #R
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 scene... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parallel_calculations | Parallel calculations | Many programming languages allow you to specify computations to be run in parallel.
While Concurrent computing is focused on concurrency,
the purpose of this task is to distribute time-consuming calculations
on as many CPUs as possible.
Assume we have a collection of numbers, and want to find the one
with the largest ... | #Racket | Racket |
#lang racket
(require math)
(provide main)
(define (smallest-factor n)
(list (first (first (factorize n))) n))
(define numbers
'(112272537195293 112582718962171 112272537095293
115280098190773 115797840077099 1099726829285419))
(define (main)
; create as many instances of Racket as
; there are numb... | Give a code snippet in #Racket
Many programming languages allow you to specify computations to be run in parallel.
While Concurrent computing is focused on concurrency,
the purpose of this task is to distribute time-consuming calculations
on as many CPUs as possible.
Assume we have a collection of numbers, and want t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Comb_sort | Sorting algorithms/Comb sort | Sorting algorithms/Comb sort
You are encouraged to solve this task according to the task description, using any language you may know.
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 algor... | #Common_Lisp | Common Lisp | (defparameter *shrink* 1.3)
(defun comb-sort (input)
(loop with input-size = (length input)
with gap = input-size
with swapped
do (when (> gap 1)
(setf gap (floor gap *shrink*)))
(setf swapped nil)
(loop for lo from 0
for hi from gap below ... | Give a code snippet in #Common_Lisp
Sorting algorithms/Comb sort
You are encouraged to solve this task according to the task description, using any language you may know.
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 com... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Set | Set |
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 set is a collection of elements, without duplicates and without order.
Task
Show each of these set operations:
Set creation
Test m ∈ S -- "m is an... | #Elixir | Elixir | iex(1)> s = MapSet.new
#MapSet<[]>
iex(2)> sa = MapSet.put(s, :a)
#MapSet<[:a]>
iex(3)> sab = MapSet.put(sa, :b)
#MapSet<[:a, :b]>
iex(4)> sbc = Enum.into([:b, :c], MapSet.new)
#MapSet<[:b, :c]>
iex(5)> MapSet.member?(sab, :a)
true
iex(6)> MapSet.member?(sab, :c)
false
iex(7)> :a in sab
true
iex(8)> MapSet.union(sab, s... | Give a code snippet in #Elixir
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 set is a collection of elements, without duplicates and without order.
Task
Show each of these set operations:
Set ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/Integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #REBOL | REBOL | rebol [
Title: "Integer"
URL: http://rosettacode.org/wiki/Arithmetic/Integer
]
x: to-integer ask "Please type in an integer, and press [enter]: "
y: to-integer ask "Please enter another integer: "
print ""
print ["Sum:" x + y]
print ["Difference:" x - y]
print ["Product:" x * y]
print ["Integer quotient (coer... | Give a code snippet in #REBOL
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_concatenation | Array concatenation | Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| #Ioke | Ioke | iik> [1,2,3] + [3,2,1]
[1,2,3] + [3,2,1]
+> [1, 2, 3, 3, 2, 1] | Give a code snippet in #Ioke
Task
Show how to concatenate two arrays in your language.
If this is as simple as array1 + array2, so be it.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would repr... | #Octave | Octave | a = [3, 4, 5];
b = [4, 3, 5];
c = [-5, -12, -13];
function r = s3prod(a, b, c)
r = dot(a, cross(b, c));
endfunction
function r = v3prod(a, b, c)
r = cross(a, cross(b, c));
endfunction
% 49
dot(a, b)
% or matrix-multiplication between row and column vectors
a * b'
% 5 5 -7
cross(a, b) % only for 3d-vectors
... | Give a code snippet in #Octave
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of n... | 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
¯... | #MATLAB_.2F_Octave | MATLAB / Octave | % Initialize
N = 0; S=0; S2 = 0;
binlist = 0:.1:1;
h = zeros(1,length(binlist)); % initialize histogram
% read data and perform computation
while (1)
% read next sample x
if (no_data_available) break; end;
N = N + 1;
S = S + x;
S2= S2+ x*x;
ix= sum(x < binlist)... | Give a code snippet in #MATLAB_.2F_Octave
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #Nanoquery | Nanoquery | import Nanoquery.IO
def get_files(dirname)
local_filenames = new(File).listDir(dirname)
filenames = {}
for i in range(0, len(local_filenames) - 1)
if len(local_filenames) > 0
if not new(File, local_filenames[i]).isDir()
filenames.append(local_filenames[i])
else
filenames += get_files(local_file... | Give a code snippet in #Nanoquery
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ordered_partitions | Ordered partitions | In this task we want to find the ordered partitions into fixed-size blocks.
This task is related to Combinations in that it has to do with discrete mathematics and moreover a helper function to compute combinations is (probably) needed to solve this task.
p
a
r
t
i
t
i
o
n
s
(
a
r
g
1
,
a
r
g
2
,
... | #Go | Go | package main
import (
"fmt"
"os"
"strconv"
)
func gen_part(n, res []int, pos int) {
if pos == len(res) {
x := make([][]int, len(n))
for i, c := range res {
x[c] = append(x[c], i+1)
}
fmt.Println(x)
return
}
for i := range n {
if n[i] == 0 {
continue
}
n[i], res[pos] = n[i]-1, i
gen... | Give a code snippet in #Go
In this task we want to find the ordered partitions into fixed-size blocks.
This task is related to Combinations in that it has to do with discrete mathematics and moreover a helper function to compute combinations is (probably) needed to solve this task.
p
a
r
t
i
t
i
o
n
s
(
a
r
g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polymorphic_copy | Polymorphic copy | An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of x were unknown, then y could not be d... | #OxygenBasic | OxygenBasic |
'======
class T
'======
float vv
method constructor(float a=0) {vv=a}
method destructor {}
method copy as T {new T ob : ob<=vv : return ob}
method mA() as float {return vv*2}
method mB() as float {return vv*3}
end class
'======
class S
'======
has T
method mB() as float {return vv*4} 'ovveride
... | Give a code snippet in #OxygenBasic
An object is polymorphic when its specific type may vary.
The types a specific value may take, is called class.
It is trivial to copy an object if its type is known:
int x;
int y = x;
Here x is not polymorphic, so y is declared of same type (int) as x.
But if the specific type of ... | 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.
| #Lua | Lua | -- any version from LuaJIT 2.0/5.1, Lua 5.2, Lua 5.3 to LuaJIT 2.1.0-beta3-readline
local bit=bit32 or bit -- Lua 5.2/5.3 compatibilty
-- Hilbert curve implemented by Lindenmayer system
function string.hilbert(s, n)
for i=1,n do
s=s:gsub("[AB]",function(c)
if c=="A" then
c="-BF+AFA+FB-"
else
c="+AF-BF... | Give a code snippet in #Lua
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Soundex | Soundex | Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is a major issue in many of the ... | #BBC_BASIC | BBC BASIC | DATA Ashcraft, Ashcroft, Gauss, Ghosh, Hilbert, Heilbronn, Lee, Lloyd
DATA Moses, Pfister, Robert, Rupert, Rubin, Tymczak, Soundex, Example
FOR i% = 1 TO 16
READ name$
PRINT """" name$ """" TAB(15) FNsoundex(name$)
NEXT
END
DEF FNsoundex(name$)
LOCAL i%, n%, p... | Give a code snippet in #BBC_BASIC
Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
The... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zero_to_the_zero_power | Zero to the zero power | Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 or 0^0 at compile time, ... | #PureBasic | PureBasic |
If OpenConsole()
PrintN("Zero to the zero power is " + Pow(0,0))
PrintN("")
PrintN("Press any key to close the console")
Repeat: Delay(10) : Until Inkey() <> ""
CloseConsole()
EndIf
| Give a code snippet in #PureBasic
Some computer programming languages are not exactly consistent (with other computer programming languages)
when raising zero to the zeroth power: 00
Task
Show the results of raising zero to the zeroth power.
If your computer language objects to 0**0 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Detect_division_by_zero | Detect division by zero | Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| #NS-HUBASIC | NS-HUBASIC | 10 ON ERROR GOTO 40
20 PRINT 1/0
30 END
40 IF ERR = 10 THEN PRINT "DIVISION BY ZERO IN LINE"ERL
50 RESUME 30 | Give a code snippet in #NS-HUBASIC
Task
Write a function to detect a divide by zero error without checking if the denominator is zero.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Universal_Turing_machine | Universal Turing machine | One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machine in it.
Task
Simulate such ... | #Yabasic | Yabasic | // Machine definitions
name = 1 : initState = 2 : endState = 3 : blank = 4 : countOnly = true
incrementer$ = "Simple incrementer,q0,qf,B"
incrementer$ = incrementer$ + ",q0,1,1,right,q0,q0,B,1,stay,qf"
threeStateBB$ = "Three-state busy beaver,a,halt,0"
data "a,0,1,right,b"
data "a,1,1,left,c"
data "b,0,1,left,a"
... | Give a code snippet in #Yabasic
One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Vala | Vala | void main() {} | Give a code snippet in #Vala
Task
Create the simplest possible program that is still considered "correct."
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sailors,_coconuts_and_a_monkey_problem | Sailors, coconuts and a monkey problem | Five sailors are shipwrecked on an island and collect a large pile of coconuts during the day.
That night the first sailor wakes up and decides to take his first share early so tries to divide the pile of coconuts equally into five piles but finds that there is one coconut left over, so he tosses it to a monkey and th... | #uBasic.2F4tH | uBasic/4tH | For n = 2 To 7
t = 0
For x = 1 Step 1 While t = 0
t = FUNC(_Total(n,x))
Next
Print n;": ";t;Tab(12); x - 1
Next
End
_Total Param(2)
Local(1)
b@ = b@ * a@
a@ = a@ - 1
For c@ = 0 To a@
If b@ % a@ Then
b@ = 0
Break
EndIf
b@ = b@ + 1 + b@ / a@
Next
Return (b@) | Give a code snippet in #uBasic.2F4tH
Five sailors are shipwrecked on an island and collect a large pile of coconuts during the day.
That night the first sailor wakes up and decides to take his first share early so tries to divide the pile of coconuts equally into five piles but finds that there is one coconut left ov... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_specific_line_from_a_file | Read a specific line from a file | Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it in a variable or in memory (fo... | #Racket | Racket |
#lang racket
;; simple, but reads the whole file
(define s1 (list-ref (file->lines "some-file") 6))
;; more efficient: read and discard n-1 lines
(define s2
(call-with-input-file "some-file"
(λ(i) (for/last ([line (in-lines i)] [n 7]) line))))
| Give a code snippet in #Racket
Some languages have special semantics for obtaining a known line number from a file.
Task
Demonstrate how to obtain the contents of a specific line within a file.
For the purpose of this task demonstrate how the contents of the seventh line of a file can be obtained, and store it ... | christopher/rosetta-code |
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