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/Five_weekends | Five weekends | The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property (there should be 201).
Show at leas... | #Common_Lisp | Common Lisp | ;; Given a date, get the day of the week. Adapted from
;; http://lispcookbook.github.io/cl-cookbook/dates_and_times.html
(defun day-of-week (day month year)
(nth-value
6
(decode-universal-time
(encode-universal-time 0 0 0 day month year 0)
0)))
(defparameter *long-months* '(1 3 5 7 8 10 12))
(defun sun... | Give a code snippet in #Common_Lisp
The month of October in 2010 has five Fridays, five Saturdays, and five Sundays.
Task
Write a program to show all months that have this same characteristic of five full weekends from the year 1900 through 2100 (Gregorian calendar).
Show the number of months with this property... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For | Loops/For | “For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract structures other than the integers.
... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols nobinary
say
say 'Loops/For'
loop i_ = 1 to 5
loop for i_
say '*\-'
end
say
end i_
| Give a code snippet in #NetRexx
“For” loops are used to make some block of code be iterated a number of times, setting a variable or parameter to a monotonically increasing integer value for each execution of the block of code.
Common extensions of this allow other counting patterns or iterating over abstract struc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_elements_below_main_diagonal_of_matrix | Sum of elements below main diagonal of matrix | Task
Find and display the sum of elements that are below the main diagonal of a matrix.
The matrix should be a square matrix.
─── Matrix to be used: ───
[[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]]
| #Python | Python | from numpy import array, tril, sum
A = [[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]]
print(sum(tril(A, -1))) # 69 | Give a code snippet in #Python
Task
Find and display the sum of elements that are below the main diagonal of a matrix.
The matrix should be a square matrix.
─── Matrix to be used: ───
[[1,3,7,8,10],
[2,4,16,14,4],
[3,1,9,18,11],
[12,14,17,18,20],
[7,1,3,9,5]]
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_directory | Empty directory | Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory); an empty directory contains no other... | #Common_Lisp | Common Lisp |
(defun empty-directory-p (path)
(and (null (directory (concatenate 'string path "/*")))
(null (directory (concatenate 'string path "/*/")))))
| Give a code snippet in #Common_Lisp
Starting with a path to some directory, determine whether the directory is empty.
An empty directory contains no files nor subdirectories.
With Unix or Windows systems, every directory contains an entry for “.” and almost every directory contains “..” (except for a root directory);... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multisplit | Multisplit | It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is to write code to demonstrate ... | #TXR | TXR | @(next :args)
@(coll :gap 0)@(choose :shortest tok)@\
@tok@{sep /==/}@\
@(or)@\
@tok@{sep /!=/}@\
@(or)@\
@tok@{sep /=/}@\
@(end)@(end)@tail
@(output)
@(rep)"@tok" {@sep} @(end)"@tail"
@(end) | Give a code snippet in #TXR
It is often necessary to split a string into pieces
based on several different (potentially multi-character) separator strings,
while still retaining the information about which separators were present in the input.
This is particularly useful when doing small parsing tasks.
The task is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Haversine_formula | Haversine formula |
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equation important in navigation, g... | #BASIC256 | BASIC256 |
global radioTierra # radio de la tierra en km
radioTierra = 6372.8
function Haversine(lat1, long1, lat2, long2 , radio)
d_long = radians(long1 - long2)
theta1 = radians(lat1)
theta2 = radians(lat2)
dx = cos(d_long) * cos(theta1) - cos(theta2)
dy = sin(d_long) * cos(theta1)
dz = sin(theta1) - sin(theta2)
r... | Give a code snippet in #BASIC256
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Lychrel_numbers | Lychrel numbers | Take an integer n, greater than zero.
Form the next n of its series by reversing the digits of the current n and adding the result to the current n.
Stop when n becomes palindromic - i.e. the digits of n in reverse order == n.
The above recurrence relation when applied to most starting numbers n = 1, 2, ... ... | #Rust | Rust | [package]
name = "lychrel"
version = "0.1.0"
authors = ["monsieursquirrel"]
[dependencies]
num = "0.1.27" | Give a code snippet in #Rust
Take an integer n, greater than zero.
Form the next n of its series by reversing the digits of the current n and adding the result to the current n.
Stop when n becomes palindromic - i.e. the digits of n in reverse order == n.
The above recurrence relation when applied to most s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comma_quibbling | Comma quibbling | Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An input of just one word, e.g. ["AB... | #BCPL | BCPL | get "libhdr"
// Add a character to the end of a string
let addch(s, ch) be
$( s%0 := s%0 + 1
s%(s%0) := ch
$)
// Add s2 to the end of s1
and adds(s1, s2) be
for i = 1 to s2%0 do
addch(s1, s2%i)
// Comma quibbling on strs, which should be a 0-terminated
// vector of string pointers.
let quibble(strs... | Give a code snippet in #BCPL
Comma quibbling is a task originally set by Eric Lippert in his blog.
Task
Write a function to generate a string output which is the concatenation of input words from a list/sequence where:
An input of no words produces the output string of just the two brace characters "{}".
An inp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_limit_of_recursion | Find limit of recursion | Find limit of recursion is part of Short Circuit's Console Program Basics selection.
Task
Find the limit of recursion.
| #Swift | Swift | var n = 1
func recurse() {
print(n)
n += 1
recurse()
}
recurse() | Give a code snippet in #Swift
Find limit of recursion is part of Short Circuit's Console Program Basics selection.
Task
Find the limit of recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sieve_of_Eratosthenes | Sieve of Eratosthenes | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes algorithm, with the only allowed... | #CMake | CMake | function(eratosthenes var limit)
# Check for integer overflow. With CMake using 32-bit signed integer,
# this check fails when limit > 46340.
if(NOT limit EQUAL 0) # Avoid division by zero.
math(EXPR i "(${limit} * ${limit}) / ${limit}")
if(NOT limit EQUAL ${i})
message(FATAL_ERROR "limit is... | Give a code snippet in #CMake
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
The Sieve of Eratosthenes is a simple algorithm that finds the prime numbers up to a given integer.
Task
Implement the Sieve of Eratosthenes a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #360_Assembly | 360 Assembly | * Dot product 03/05/2016
DOTPROD CSECT
USING DOTPROD,R15
SR R7,R7 p=0
LA R6,1 i=1
LOOPI CH R6,=AL2((B-A)/4) do i=1 to hbound(a)
BH ELOOPI
LR R1,R6 i
SLA R1,2 *4
... | Give a code snippet in #360_Assembly
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Day_of_the_week | Day of the week | A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years between 2008 and 2121 will the 25th of ... | #J | J | load 'dates' NB. provides verb 'weekday'
xmasSunday=: #~ 0 = [: weekday 12 25 ,~"1 0 ] NB. returns years where 25 Dec is a Sunday
xmasSunday 2008 + i.114 NB. check years from 2008 to 2121
2011 2016 2022 2033 2039 2044 2050 2061 2067 2072 2078 2089 20... | Give a code snippet in #J
A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years between 2008... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fork | Fork | Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| #ooRexx | ooRexx | sub=.fork~new
sub~sub
Call syssleep 1
Do 3
Say 'program ' time()
Call syssleep 1
End
::class fork
:: method sub
Reply
Do 6
Say 'subroutine' time()
Call syssleep 1
End | Give a code snippet in #ooRexx
Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #VBScript | VBScript |
Set objNetwork = CreateObject("WScript.Network")
WScript.Echo objNetwork.ComputerName
| Give a code snippet in #VBScript
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Common_Lisp | Common Lisp | (defun factorial (n)
(if (zerop n) 1 (* n (factorial (1- n))))) | Give a code snippet in #Common_Lisp
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #Dao | Dao | syntax{Q $EXP}as{io.writef('syntax{Q $EXP}as{%s}Q %s',\'$EXP\',\'$EXP\')}Q io.writef('syntax{Q $EXP}as{%s}Q %s',\'$EXP\',\'$EXP\') | Give a code snippet in #Dao
A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Handle_a_signal | Handle a signal | Most operating systems provide interrupt facilities, sometimes called signals either generated by the user or as a result of program failure or reaching a limit like file space.
Unhandled signals generally terminate a program in a disorderly manner.
Signal handlers are created so that the program behaves in a well-defi... | #Smalltalk | Smalltalk | |n|
n := 0.
UserInterrupt
catch:[
[true] whileTrue:[
n := n + 1.
n printCR.
Delay waitForSeconds: 0.5.
]
] | Give a code snippet in #Smalltalk
Most operating systems provide interrupt facilities, sometimes called signals either generated by the user or as a result of program failure or reaching a limit like file space.
Unhandled signals generally terminate a program in a disorderly manner.
Signal handlers are created so that... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Morse_code | Morse code | Morse code
It has been in use for more than 175 years — longer than any other electronic encoding system.
Task
Send a string as audible Morse code to an audio device (e.g., the PC speaker).
As the standard Morse code does not contain all possible characters,
you may either ignore unknown characters in the file... | #PicoLisp | PicoLisp | # *Morse *Dit *Dah
(balance '*Morse
(mapcar
'((L)
(def (car L)
(mapcar = (chop (cadr L)) '("." .)) ) )
(quote
("!" "---.") ("\"" ".-..-.") ("$" "...-..-") ("'" ".----.")
("(" "-.--.") (")" "-.--.-") ("+" ".-.-.") ("," "--..--")
("-" "-... | Give a code snippet in #PicoLisp
Morse code
It has been in use for more than 175 years — longer than any other electronic encoding system.
Task
Send a string as audible Morse code to an audio device (e.g., the PC speaker).
As the standard Morse code does not contain all possible characters,
you may either ign... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_variables | Special variables | Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| #Java | Java | import java.util.Arrays;
public class SpecialVariables {
public static void main(String[] args) {
//String-Array args contains the command line parameters passed to the program
//Note that the "Arrays.toString()"-call is just used for pretty-printing
System.out.println(Arrays.toString(... | Give a code snippet in #Java
Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Truth_table | Truth table | A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate and print a formatted truth table for the g... | #C | C | #include <stdio.h>
#include <string.h>
#include <stdlib.h>
#define TRUE 1
#define FALSE 0
#define STACK_SIZE 80
#define BUFFER_SIZE 100
typedef int bool;
typedef struct {
char name;
bool val;
} var;
typedef struct {
int top;
bool els[STACK_SIZE];
} stack_of_bool;
char expr[BUFFER_SIZE];
int ex... | Give a code snippet in #C
A truth table is a display of the inputs to, and the output of a Boolean function organized as a table where each row gives one combination of input values and the corresponding value of the function.
Task
Input a Boolean function from the user as a string then calculate and print a form... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Synchronous_concurrency | Synchronous concurrency | The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with different names. Some languages use th... | #Erlang | Erlang | -module(cc).
-export([start/0]).
start() ->
My_pid = erlang:self(),
Pid = erlang:spawn( fun() -> reader(My_pid, 0) end ),
{ok, IO } = file:open( "input.txt", [read] ),
process( io:get_line(IO, ""), IO, Pid ),
file:close( IO ).
process( eof, _IO, Pid ) ->
Pid ! count,
receive
I -> io:fw... | Give a code snippet in #Erlang
The goal of this task is to create two concurrent activities ("Threads" or "Tasks", not processes.) that share data synchronously. Your language may provide syntax or libraries to perform concurrency. Different languages provide different implementations of concurrency, often with differ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #Ruby | Ruby | m=[[1, 1, 1, 1],
[2, 4, 8, 16],
[3, 9, 27, 81],
[4, 16, 64, 256],
[5, 25,125, 625]]
puts m.transpose | Give a code snippet in #Ruby
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/File_input/output | File input/output | File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into a variable
how to write ... | #Zig | Zig | const std = @import("std");
pub fn main() !void {
var in = try std.fs.cwd().openFile("input.txt", .{});
defer in.close();
var out = try std.fs.cwd().openFile("output.txt", .{ .mode = .write_only });
defer out.close();
var file_reader = in.reader();
var file_writer = out.writer();
var buf: ... | Give a code snippet in #Zig
File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file int... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #M4 | M4 | # The macros which return a pair of values x,y expand to an unquoted 123,456
# which is suitable as arguments to a further macro. The quoting is slack
# because the values are always integers and so won't suffer unwanted macro
# expansion.
# 0,1 Vertex and segment x,y numbering.
# ... | Give a code snippet in #M4
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_an_HTML_table | Create an HTML table | Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers.
The... | #C.23 | C# | using System;
using System.Text;
namespace prog
{
class MainClass
{
public static void Main (string[] args)
{
StringBuilder s = new StringBuilder();
Random rnd = new Random();
s.AppendLine("<table>");
s.AppendLine("<thead align = \"right\">");
s.Append("<tr><th></th>");
for(int i=0; i<3; i... | Give a code snippet in #C.23
Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pierpont_primes | Pierpont primes | A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v .
A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v .
The term "Pierpont primes" is generally understood to mean the first definition, but will be c... | #Lua | Lua | local function isprime(n)
if n < 2 then return false end
if n % 2 == 0 then return n==2 end
if n % 3 == 0 then return n==3 end
local f, limit = 5, math.sqrt(n)
for f = 5, limit, 6 do
if n % f == 0 then return false end
if n % (f+2) == 0 then return false end
end
return true
end
local function s3... | Give a code snippet in #Lua
A Pierpont prime is a prime number of the form: 2u3v + 1 for some non-negative integers u and v .
A Pierpont prime of the second kind is a prime number of the form: 2u3v - 1 for some non-negative integers u and v .
The term "Pierpont primes" is generally understood to mean the fi... | 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 ... | #Swift | Swift | import Foundation
print("Input max number: ", terminator: "")
guard let maxN = Int(readLine() ?? "0"), maxN > 0 else {
fatalError("Please input a number greater than 0")
}
func getFactor() -> (Int, String) {
print("Enter a factor and phrase: ", terminator: "")
guard let factor1Input = readLine() else {
... | Give a code snippet in #Swift
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 wit... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Map_range | Map range | Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly mapped to a value
t
{\di... | #Stata | Stata | program define maprange
version 15.1
syntax varname(numeric) [if] [in], ///
from(numlist min=2 max=2) to(numlist min=2 max=2) ///
GENerate(name) [REPLACE]
tempname a b c d h
sca `a'=`:word 1 of `from''
sca `b'=`:word 2 of `from''
sca `c'=`:word 1 of `to''
sca `d'=`:word 2 of `to''
sca `h'=(`d'-`c')/(`b'-`a'... | Give a code snippet in #Stata
Given two ranges:
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
and
[
b
1
,
b
2
]
{\displaystyle [b_{1},b_{2}]}
;
then a value
s
{\displaystyle s}
in range
[
a
1
,
a
2
]
{\displaystyle [a_{1},a_{2}]}
is linearly m... | 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... | #m4 | m4 | divert(-1)
define(`loop',
`ifelse(eval(0 < ($1)),1,`$1`
'loop(eval(($1) / 2))')')
divert`'dnl
loop(1024)dnl | Give a code snippet in #m4
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 f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n)... | #Swift | Swift | var deficients = 0 // sumPd < n
var perfects = 0 // sumPd = n
var abundants = 0 // sumPd > n
// 1 is deficient (no proper divisor)
deficients++
for i in 2...20000 {
var sumPd = 1 // 1 is a proper divisor of all integer above 1
var maxPdToTest = i/2 // the max divisor to test
for var j = 2; j < m... | Give a code snippet in #Swift
These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient... | 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... | #MAXScript | MAXScript | inclusiveRange = [1,100]
lowRange = inclusiveRange.x
maxRange = inclusiveRange.y
guesses = 1
inf = "Think of a number between % and % and I will try to guess it.\n" +\
"Type -1 if the guess is less than your number,\n"+\
"0 if the guess is correct, " +\
"or 1 if it's too high.\nPress esc to exit.\n"
clearListene... | Give a code snippet in #MAXScript
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. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Forest_fire | Forest fire |
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and Schwabl definition of the fores... | #Erlang | Erlang |
-module( forest_fire ).
-export( [task/0] ).
-record( state, {neighbours=[], position, probability_burn, probability_grow, tree} ).
task() ->
erlang:spawn( fun() ->
Pid_positions = forest_create( 5, 5, 0.5, 0.3, 0.2 ),
Pids = [X || {X, _} <- Pid_positions],
[X ! {tr... | Give a code snippet in #Erlang
This page uses content from Wikipedia. The original article was at Forest-fire model. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Implement the Drossel and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Barnsley_fern | Barnsley fern |
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 yn
ƒ2 (chosen 85% of the time)
... | #TI-83_BASIC | TI-83 BASIC | ClrDraw
Input "ITERS:",M
[[0,0,1]]→[A]
[[0,0,0][0,.16,0][0,0,1]]→[B]
[[.85,-.04,0][.04,.85,0][0,1.6,1]]→[C]
[[.2,.23,0][-.26,.22,0][0,1.6,1]]→[D]
[[-.15,.26,0][.28,.24,0][0,.44,1]]→[E]
0→I
While I<M
randInt(1,100)→R
If R=1
Then
[A][B]→[A]
101→R
End
If R<86
Then
[A][C]→[A]
101→R
End
If R<93
Then
[A][D]→[A]
101→R
E... | Give a code snippet in #TI-83_BASIC
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #Scheme | Scheme | (define pi (* 4 (atan 1)))
(do ((n 2 (+ n 1)))
((> n 10))
(display n)
(do ((k 0 (+ k 1)))
((>= k n))
(display " ")
(display (make-polar 1 (* 2 pi (/ k n)))))
(newline)) | Give a code snippet in #Scheme
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
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
... | #PicoLisp | PicoLisp | (let (X 77444 Y -12 Z 0)
(println X Y Z)
(mapc set '(X Y Z) (sort (list X Y Z)))
(println X Y Z) ) | Give a code snippet in #PicoLisp
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Real_constants_and_functions | Real constants and functions | Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "magnitude")
floor (largest ... | #ACL2 | ACL2 | (floor 15 2) ;; This is the floor of 15/2
(ceiling 15 2)
(expt 15 2) ;; 15 squared | Give a code snippet in #ACL2
Task
Show how to use the following math constants and functions in your language (if not available, note it):
e (base of the natural logarithm)
π
{\displaystyle \pi }
square root
logarithm (any base allowed)
exponential (ex )
absolute value (a.k.a. "ma... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unicode_strings | Unicode strings | As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is your programming language for ... | #C.23 | C# |
(defvar ♥♦♣♠ "♥♦♣♠")
(defun ✈ () "a plane unicode function")
| Give a code snippet in #C.23
As the world gets smaller each day, internationalization becomes more and more important. For handling multiple languages, Unicode is your best friend.
It is a very capable tool, but also quite complex compared to older single- and double-byte character encodings.
How well prepared is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/15_puzzle_game | 15 puzzle game |
Task
Implement the Fifteen Puzzle Game.
The 15-puzzle is also known as:
Fifteen Puzzle
Gem Puzzle
Boss Puzzle
Game of Fifteen
Mystic Square
14-15 Puzzle
and some others.
Related Tasks
15 Puzzle Solver
16 Puzzle Game
| #x86-64_Assembly | x86-64 Assembly | ; Puzzle15 by grosged (march 2019)
; How to play ?.. Just press one of the arrow keys then [enter] to valid
; ( press [Ctrl+C] to escape )
segment .data
check: db "1 2 3 4",10," 5 6 7 8",10," 9 10 11 12",10," 13 14 1"
puzzle: db 27,"c",10," 1 2 3 4",10," 5 ... | Give a code snippet in #x86-64_Assembly
Task
Implement the Fifteen Puzzle Game.
The 15-puzzle is also known as:
Fifteen Puzzle
Gem Puzzle
Boss Puzzle
Game of Fifteen
Mystic Square
14-15 Puzzle
and some others.
Related Tasks
15 Puzzle Solver
16 Puzzle Game
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Numerical_integration | Numerical integration | Write functions to calculate the definite integral of a function ƒ(x) using all five of the following methods:
rectangular
left
right
midpoint
trapezium
Simpson's
composite
Your functions should take in the upper and lower bounds (a and b), and the number of approximations to make in that range (n).
Assume t... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | leftRect[f_, a_Real, b_Real, N_Integer] :=
Module[{sum = 0, dx = (b - a)/N, x = a, n = N} ,
For[n = N, n > 0, n--, x += dx; sum += f[x];];
Return [ sum*dx ]]
rightRect[f_, a_Real, b_Real, N_Integer] :=
Module[{sum = 0, dx = (b - a)/N, x = a + (b - a)/N, n = N} ,
For[n = N, n > 0, n--, x += dx; sum += f[x];]... | Give a code snippet in #Mathematica.2FWolfram_Language
Write functions to calculate the definite integral of a function ƒ(x) using all five of the following methods:
rectangular
left
right
midpoint
trapezium
Simpson's
composite
Your functions should take in the upper and lower bounds (a and b), and the numbe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newline_omission | Hello world/Newline omission | Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standard error
Hello world/Text
| #Raku | Raku | print "Goodbye, World!";
printf "%s", "Goodbye, World!"; | Give a code snippet in #Raku
Some languages automatically insert a newline after outputting a string, unless measures are taken to prevent its output.
Task
Display the string Goodbye, World! without a trailing newline.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Standa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Bracmat | Bracmat | ( put$"Enter a variable name: "
& get$:?name
& whl
' ( put$"Enter a numeric value: "
& get$:?numeric:~#
)
& !numeric:?!name
& put$(str$("Variable " !name " now has the value " !!name \n))
); | Give a code snippet in #Bracmat
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Trigonometric_functions | Trigonometric functions | Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluate to the same angle (that i... | #C | C | #include <math.h>
#include <stdio.h>
int main() {
double pi = 4 * atan(1);
/*Pi / 4 is 45 degrees. All answers should be the same.*/
double radians = pi / 4;
double degrees = 45.0;
double temp;
/*sine*/
printf("%f %f\n", sin(radians), sin(degrees * pi / 180));
/*cosine*/
printf("%f %f\n", cos(radian... | Give a code snippet in #C
Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluate ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Humble_numbers | Humble numbers | Humble numbers are positive integers which have no prime factors > 7.
Humble numbers are also called 7-smooth numbers, and sometimes called highly composite,
although this conflicts with another meaning of highly composite numbers.
Another way to express the above is:
humble = 2i × 3j × 5k... | #Quackery | Quackery | ' [ 2 3 5 7 ] smoothwith
[ -1 peek [ 10 12 ** ] constant = ]
-1 split drop
dup 50 split drop echo cr cr
12 times
[ dup 0 over size
rot 10 i^ 1+ ** searchwith <
drop split swap size echo
sp i^ 1+ echo
say "-digit humble numbers" cr ]
drop
| Give a code snippet in #Quackery
Humble numbers are positive integers which have no prime factors > 7.
Humble numbers are also called 7-smooth numbers, and sometimes called highly composite,
although this conflicts with another meaning of highly composite numbers.
Another way to express the ab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Inverted_index | Inverted index | An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / terms.
The search index can be i... | #Tcl | Tcl | package require Tcl 8.5
proc wordsInString str {
# We define "words" to be "maximal sequences of 'word' characters".
# The other possible definition is to use 'non-space' characters.
regexp -all -inline {\w+} $str
}
# Adds a document to the index. The index is a map from words to a map
# from filenames to... | Give a code snippet in #Tcl
An Inverted Index is a data structure used to create full text search.
Task
Given a set of text files, implement a program to create an inverted index.
Also create a user interface to do a search using that inverted index which returns a list of files that contain the query term / term... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Positional_read | Terminal control/Positional read | Determine the character displayed on the screen at column 3, row 6 and store that character in a variable. Note that it is permissible to utilize system or language provided methods or system provided facilities, system maintained records or available buffers or system maintained display records to achieve this task, r... | #TXR | TXR | ;;; Type definitions and constants
(typedef BOOL (enum BOOL FALSE TRUE))
(typedef HANDLE cptr)
(typedef WCHAR wchar)
(typedef DWORD uint32)
(typedef WORD uint16)
(typedef SHORT short)
(typedef COORD
(struct COORD
(X SHORT)
(Y SHORT)))
(typedef SMALL_RECT
(struct SMALL_RECT
... | Give a code snippet in #TXR
Determine the character displayed on the screen at column 3, row 6 and store that character in a variable. Note that it is permissible to utilize system or language provided methods or system provided facilities, system maintained records or available buffers or system maintained display re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/M%C3%B6bius_function | Möbius function | The classical Möbius function: μ(n) is an important multiplicative function in number theory and combinatorics.
There are several ways to implement a Möbius function.
A fairly straightforward method is to find the prime factors of a positive integer n, then define μ(n) based on the sum of the primitive factors. It ha... | #BASIC256 | BASIC256 | function mobius(n)
if n = 1 then return 1
for d = 2 to int(sqr(n))
if n mod d = 0 then
if n mod (d*d) = 0 then return 0
return -mobius(n/d)
end if
next d
return -1
end function
outstr$ = " . "
for i = 1 to 200
if mobius(i) >= 0 then outstr$ += " "
outstr$ += string(mobius(i)) + " "
if i mod 10 = ... | Give a code snippet in #BASIC256
The classical Möbius function: μ(n) is an important multiplicative function in number theory and combinatorics.
There are several ways to implement a Möbius function.
A fairly straightforward method is to find the prime factors of a positive integer n, then define μ(n) based on the s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Web_server | Hello world/Web server | The browser is the new GUI !
Task
Serve our standard text Goodbye, World! to http://localhost:8080/ so that it can be viewed with a web browser.
The provided solution must start or implement a server that accepts multiple client connections and serves text as requested.
Note that starting a web browser or... | #Lasso | Lasso | local(server) = net_tcp
handle => { #server->close }
#server->bind(8080) & listen & forEachAccept => {
local(con) = #1
split_thread => {
handle => { #con->close }
local(request) = ''
// Read in the request in chunks until you have it all
{
#request->append(#con->readSomeBytes(80... | Give a code snippet in #Lasso
The browser is the new GUI !
Task
Serve our standard text Goodbye, World! to http://localhost:8080/ so that it can be viewed with a web browser.
The provided solution must start or implement a server that accepts multiple client connections and serves text as requested.
Note... | 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 ... | #PL.2FM | PL/M | 100H:
BDOS: PROCEDURE (FN, ARG); DECLARE FN BYTE, ARG ADDRESS; GO TO 5; END BDOS;
EXIT: PROCEDURE; CALL BDOS(0,0); END EXIT;
PRINT: PROCEDURE (S); DECLARE S ADDRESS; CALL BDOS(9,S); END PRINT;
PRINT$NUMBER: PROCEDURE (N);
DECLARE S (6) BYTE INITIAL ('.....$');
DECLARE (N, P) ADDRESS, C BASED P BYTE;
P = .... | Give a code snippet in #PL.2FM
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions ar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_input/output | File input/output | File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into a variable
how to write ... | #Emacs_Lisp | Emacs Lisp | (defvar input (with-temp-buffer
(insert-file-contents "input.txt")
(buffer-string)))
(with-temp-file "output.txt"
(insert input))
| Give a code snippet in #Emacs_Lisp
File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_using_a_custom_comparator | Sort using a custom comparator |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #zkl | zkl | s:=T("Cat","apple","Adam","zero","Xmas","quit","Level","add","Actor","base","butter");
r:=s.sort(fcn(a,b){
an,bn := a.len(),b.len();
if(an==bn)(a.toLower() < b.toLower()) else (an > bn)
});
r.pump(Console.println); | Give a code snippet in #zkl
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #MAXScript | MAXScript | m = bigMatrix 5 4
for i in 1 to 5 do for j in 1 to 4 do m[i][j] = pow i j
m = transpose m | Give a code snippet in #MAXScript
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_two_numerical_lists | Order two numerical lists | sorting
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
She... | #ALGOL_W | ALGOL W | begin % compare lists (rows) of integers %
% returns TRUE if there is an element in a that is < the corresponding %
% element in b and all previous elements are equal, FALSE otherwise %
% the bounds of a and b should aLb :: aUb and bLb :: bUb %
logical procedure iLT ( integer array a ( ... | Give a code snippet in #ALGOL_W
sorting
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maze_generation | Maze generation |
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Generate and show a maze, using the simple Depth... | #Rascal | Rascal | import IO;
import util::Math;
import List;
public void make_maze(int w, int h){
vis = [[0 | _ <- [1..w]] | _ <- [1..h]];
ver = [["| "| _ <- [1..w]] + ["|"] | _ <- [1..h]] + [[]];
hor = [["+--"| _ <- [1..w]] + ["+"] | _ <- [1..h + 1]];
void walk(int x, int y){
vis[y][x] = 1;
d = [<x - 1, y>, <x, y + 1>, <... | Give a code snippet in #Rascal
This page uses content from Wikipedia. The original article was at Maze generation algorithm. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Generate and sho... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Modula-3 | Modula-3 | PROCEDURE FactIter(n: CARDINAL): CARDINAL =
VAR
result := n;
counter := n - 1;
BEGIN
FOR i := counter TO 1 BY -1 DO
result := result * i;
END;
RETURN result;
END FactIter; | Give a code snippet in #Modula-3
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Untouchable_numbers | Untouchable numbers | Definitions
Untouchable numbers are also known as nonaliquot numbers.
An untouchable number is a positive integer that cannot be expressed as the sum of all the proper divisors of any positive integer. (From Wikipedia)
The sum of all the proper divisors is also known as the aliquot sum.
A... | #Perl | Perl | use strict;
use warnings;
use enum qw(False True);
use ntheory qw/divisor_sum is_prime/;
sub sieve {
my($n) = @_;
my %s;
for my $k (0 .. $n+1) {
my $sum = divisor_sum($k) - $k;
$s{$sum} = True if $sum <= $n+1;
}
%s
}
my(%s,%c);
my($max, $limit, $cnt) = (2000, 1e5, 0);
%s = siev... | Give a code snippet in #Perl
Definitions
Untouchable numbers are also known as nonaliquot numbers.
An untouchable number is a positive integer that cannot be expressed as the sum of all the proper divisors of any positive integer. (From Wikipedia)
The sum of all the proper divisors is also know... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_missing_permutation | Find the missing permutation | ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
CDBA
... | #Julia | Julia | using BenchmarkTools, Combinatorics
function missingperm(arr::Vector)
allperms = String.(permutations(arr[1])) # revised for type safety
for perm in allperms
if perm ∉ arr return perm end
end
end
arr = ["ABCD", "CABD", "ACDB", "DACB", "BCDA", "ACBD", "ADCB", "CDAB", "DABC", "BCAD",
"CADB... | Give a code snippet in #Julia
ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
... | 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... | #Zig | Zig | const std = @import("std");
const debug = std.debug;
const mem = std.mem;
test "copy a string" {
const source = "A string.";
// Variable `dest1` will have the same type as `source`, which is
// `*const [9:0]u8`.
const dest1 = source;
// Variable `dest2`'s type is [9]u8.
//
// The dif... | Give a code snippet in #Zig
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 str... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #PHP | PHP | <?php
$str = ''; // assign an empty string to a variable
// check that a string is empty
if (empty($str)) { ... }
// check that a string is not empty
if (! empty($str)) { ... }
// we could also use the following
if ($str == '') { ... }
if ($str != '') { ... }
if (strlen($str) == 0) { ... }
if (strlen($str) !=... | Give a code snippet in #PHP
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other... | christopher/rosetta-code | |
http://rosettacode.org/wiki/24_game | 24 game | The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four digits, used exactly once each. T... | #Quackery | Quackery | [ stack ] is operators ( --> s )
0 $ "*/+-" witheach [ bit | ]
operators put
[ stack ] is numbers ( --> s )
[ 0 swap
witheach [ bit | ]
numbers put ] is putnumbers (... | Give a code snippet in #Quackery
The 24 Game tests one's mental arithmetic.
Task
Write a program that randomly chooses and displays four digits, each from 1 ──► 9 (inclusive) with repetitions allowed.
The program should prompt for the player to enter an arithmetic expression using just those, and all of those four... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Text | Hello world/Text | Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
| #Swift | Swift | print("Hello world!") | Give a code snippet in #Swift
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Delphi | Delphi | if (input.Field == "Hello World") {
sVar = "good";
} else if (input.Field == "Bye World") {
sVar = "bad";
} else {
sVar = "neutral";
} | Give a code snippet in #Delphi
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Department_numbers | Department numbers | There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique (different from each other) and mu... | #Quackery | Quackery | [ 2dup = iff
[ 2drop drop ] done
dip over swap over = iff
[ 2drop drop ] done
rot echo sp
swap echo sp
echo cr ] is fire ( pol san fir --> )
[ 2dup = iff 2drop done
12 over -
dip over swap -
dup 1 < iff
[ 2drop drop ] done
dup 7 > iff
... | Give a code snippet in #Quackery
There is a highly organized city that has decided to assign a number to each of their departments:
police department
sanitation department
fire department
Each department can have a number between 1 and 7 (inclusive).
The three department numbers are to be unique ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parsing/RPN_calculator_algorithm | Parsing/RPN calculator algorithm | Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the RPN expression generated from the... | #C.2B.2B | C++ | #include <vector>
#include <string>
#include <sstream>
#include <iostream>
#include <cmath>
#include <algorithm>
#include <iterator>
#include <cstdlib>
double rpn(const std::string &expr){
std::istringstream iss(expr);
std::vector<double> stack;
std::cout << "Input\tOperation\tStack after" << std::endl;
std::... | Give a code snippet in #C.2B.2B
Task
Create a stack-based evaluator for an expression in reverse Polish notation (RPN) that also shows the changes in the stack as each individual token is processed as a table.
Assume an input of a correct, space separated, string of tokens of an RPN expression
Test with the ... | 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
| #D | D | void main() {
import std.array, std.range;
immutable hash = ["a", "b", "c"].zip([1, 2, 3]).assocArray;
} | Give a code snippet in #D
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/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... | #Tcl | Tcl | % clock format 0 -gmt 1
Thu Jan 01 00:00:00 GMT 1970 | Give a code snippet in #Tcl
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 sce... | christopher/rosetta-code | |
http://rosettacode.org/wiki/History_variables | History variables | Storing the history of objects in a program is a common task.
Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging.
History variables are variables in a programming la... | #Lua | Lua | -- History variables in Lua 6/12/2020 db
local HistoryVariable = {
new = function(self)
return setmetatable({history={}},self)
end,
get = function(self)
return self.history[#self.history]
end,
set = function(self, value)
self.history[#self.history+1] = value
end,
undo = function(self)
self... | Give a code snippet in #Lua
Storing the history of objects in a program is a common task.
Maintaining the history of an object in a program has traditionally required programmers either to write specific code for handling the historical data, or to use a library which supports history logging.
History variables are ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Haversine_formula | Haversine formula |
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equation important in navigation, g... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language |
distance[{theta1_, phi1_}, {theta2_, phi2_}] :=
2*6378.14 ArcSin@
Sqrt[Haversine[(theta2 - theta1) Degree] +
Cos[theta1*Degree] Cos[theta2*Degree] Haversine[(phi2 - phi1) Degree]]
| Give a code snippet in #Mathematica_.2F_Wolfram_Language
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The h... | 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
| #Wren | Wren | /* check_output_device_is_terminal.wren */
class C {
foreign static isOutputDeviceTerminal
}
System.print("Output device is a terminal = %(C.isOutputDeviceTerminal)") | Give a code snippet in #Wren
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/Haversine_formula | Haversine formula |
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equation important in navigation, g... | #UBASIC | UBASIC |
10 Point 7 'Sets decimal display to 32 places (0+.1^56)
20 Rf=#pi/180 'Degree -> Radian Conversion
100 ?Using(,7),.DxH(36+7.2/60,-(86+40.2/60),33+56.4/60,-(118+24/60));" km"
999 End
1000 '*** Haversine Distance Function ***
1010 .DxH(Lat_s,Long_s,Lat_f,Long_f)
1020 L_s=Lat_s*rf:L_f=Lat_f*rf:LD=L_f... | Give a code snippet in #UBASIC
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Simple_turtle_graphics | Simple turtle graphics | The first turtle graphic discussed in Mindstorms: Children, Computers, and Powerful Ideas by Seymour Papert is a simple drawing of a house. It is a square with a triangle on top for the roof.
For a slightly more advanced audience, a more practical introduction to turtle graphics might be to draw a bar chart.
See imag... | #Action.21 | Action! | INCLUDE "D2:TURTLE.ACT" ;from the Action! Tool Kit
PROC Rectangle(INT w,h)
BYTE i
FOR i=1 TO 2
DO
Forward(h)
Left(90)
Forward(w)
Left(90)
OD
RETURN
PROC Square(INT w)
Rectangle(w,w)
RETURN
PROC Triangle(INT w)
BYTE i
FOR i=1 TO 3
DO
Forward(w)
Right(120)
OD
RETURN
P... | Give a code snippet in #Action.21
The first turtle graphic discussed in Mindstorms: Children, Computers, and Powerful Ideas by Seymour Papert is a simple drawing of a house. It is a square with a triangle on top for the roof.
For a slightly more advanced audience, a more practical introduction to turtle graphics migh... | 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... | #Pascal | Pascal | program nSmoothNumbers(output);
const
primeCount = 538;
{$ifDef __GPC__} {$setLimit=3889} {$endIf}
cardinalMax = 3888;
type
cardinal = 0..cardinalMax;
cardinals = set of cardinal;
cardinalPositive = 1..cardinalMax;
natural = 1..maxInt;
primeIndex = 1..primeCount;
list = array[primeIndex] of cardinal;
... | Give a code snippet in #Pascal
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reduced_row_echelon_form | Reduced row echelon form | Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
(for most languages, this wil... | #Tcl | Tcl | package require Tcl 8.5
namespace path {::tcl::mathop ::tcl::mathfunc}
proc toRREF {m} {
set lead 0
lassign [size $m] rows cols
for {set r 0} {$r < $rows} {incr r} {
if {$cols <= $lead} {
break
}
set i $r
while {[lindex $m $i $lead] == 0} {
incr i
... | Give a code snippet in #Tcl
Reduced row echelon form
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Show how to compute the reduced row echelon form
(a.k.a. row canonical form) of a matrix.
The matrix can be stored in any datatype that is convenient
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Encode | Roman numerals/Encode | Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a value of zero.
In Roman numeral... | #Objeck | Objeck |
bundle Default {
class Roman {
nums: static : Int[];
rum : static : String[];
function : Init() ~ Nil {
nums := [1000, 900, 500, 400, 100, 90, 50, 40, 10, 9, 5, 4, 1];
rum := ["M", "CM", "D", "CD", "C", "XC", "L", "XL", "X", "IX", "V", "IV", "I"];
}
function : native : ToRoman(nu... | Give a code snippet in #Objeck
Task
Create a function taking a positive integer as its parameter and returning a string containing the Roman numeral representation of that integer. Modern Roman numerals are written by expressing each digit separately, starting with the left most digit and skipping any digit with a va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delete_a_file | Delete a file | Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #Slate | Slate | (File newNamed: 'input.txt') delete.
(File newNamed: '/input.txt') delete.
(Directory newNamed: 'docs') delete.
(Directory newNamed: '/docs') delete. | Give a code snippet in #Slate
Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Verhoeff_algorithm | Verhoeff algorithm | Description
The Verhoeff algorithm is a checksum formula for error detection developed by the Dutch mathematician Jacobus Verhoeff and first published in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two adjacent digits, which was at t... | #Python | Python | MULTIPLICATION_TABLE = [
(0, 1, 2, 3, 4, 5, 6, 7, 8, 9),
(1, 2, 3, 4, 0, 6, 7, 8, 9, 5),
(2, 3, 4, 0, 1, 7, 8, 9, 5, 6),
(3, 4, 0, 1, 2, 8, 9, 5, 6, 7),
(4, 0, 1, 2, 3, 9, 5, 6, 7, 8),
(5, 9, 8, 7, 6, 0, 4, 3, 2, 1),
(6, 5, 9, 8, 7, 1, 0, 4, 3, 2),
(7, 6, 5, 9, 8, 2, 1, 0, 4, 3),
(8,... | Give a code snippet in #Python
Description
The Verhoeff algorithm is a checksum formula for error detection developed by the Dutch mathematician Jacobus Verhoeff and first published in 1969. It was the first decimal check digit algorithm which detects all single-digit errors, and all transposition errors involving two... | 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... | #Brat | Brat | mean = { list |
true? list.empty?, 0, { list.reduce(0, :+) / list.length }
}
p mean 1.to 10 #Prints 5.5 | Give a code snippet in #Brat
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 estab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FASTA_format | FASTA format | In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Rosetta_Example_1
THERECANBENOSPACE
... | #BASIC | BASIC | FUNCTION checkNoSpaces (s$)
FOR i = 1 TO LEN(s$) - 1
IF MID$(s$, i, 1) = CHR$(32) OR MID$(s$, i, 1) = CHR$(9) THEN checkNoSpaces = 0
NEXT i
checkNoSpaces = 1
END FUNCTION
OPEN "input.fasta" FOR INPUT AS #1
first = 1
DO WHILE NOT EOF(1)
LINE INPUT #1, ln$
IF LEFT$(ln$, 1) = ">" THEN
... | Give a code snippet in #BASIC
In bioinformatics, long character strings are often encoded in a format called FASTA.
A FASTA file can contain several strings, each identified by a name marked by a > (greater than) character at the beginning of the line.
Task
Write a program that reads a FASTA file such as:
>Roset... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #Quackery | Quackery | [ table ] is crctable ( n --> n )
256 times
[ i^ 8 times
[ dup 1 >>
swap 1 & if
[ hex EDB88320 ^ ] ]
' crctable put ]
[ hex FFFFFFFF swap
witheach
[ over ^ hex FF &
crctable
swap 8 >> ^ ]
hex FFFFFFFF ^ ] is cr... | Give a code snippet in #Quackery
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Emacs_Lisp | Emacs Lisp | (set (intern (read-string "Enter variable name: ")) 123) | Give a code snippet in #Emacs_Lisp
Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #Logo | Logo | to compute_means :count
local "sum
make "sum 0
local "product
make "product 1
local "reciprocal_sum
make "reciprocal_sum 0
repeat :count [
make "sum sum :sum repcount
make "product product :product repcount
make "reciprocal_sum sum :reciprocal_sum (quotient repcount)
]
output (sen... | Give a code snippet in #Logo
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/DNS_query | DNS query | DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| #Clojure | Clojure | (import java.net.InetAddress java.net.Inet4Address java.net.Inet6Address)
(doseq [addr (InetAddress/getAllByName "www.kame.net")]
(cond
(instance? Inet4Address addr) (println "IPv4:" (.getHostAddress addr))
(instance? Inet6Address addr) (println "IPv6:" (.getHostAddress addr)))) | Give a code snippet in #Clojure
DNS is an internet service that maps domain names, like rosettacode.org, to IP addresses, like 66.220.0.231.
Use DNS to resolve www.kame.net to both IPv4 and IPv6 addresses. Print these addresses.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Seven-sided_dice_from_five-sided_dice | Seven-sided dice from five-sided dice | Task
(Given an equal-probability generator of one of the integers 1 to 5
as dice5), create dice7 that generates a pseudo-random integer from
1 to 7 in equal probability using only dice5 as a source of random
numbers, and check the distribution for at least one million calls using the function created in Simple R... | #Go | Go | package main
import (
"fmt"
"math"
"math/rand"
"time"
)
// "given"
func dice5() int {
return rand.Intn(5) + 1
}
// function specified by task "Seven-sided dice from five-sided dice"
func dice7() (i int) {
for {
i = 5*dice5() + dice5()
if i < 27 {
break
}... | Give a code snippet in #Go
Task
(Given an equal-probability generator of one of the integers 1 to 5
as dice5), create dice7 that generates a pseudo-random integer from
1 to 7 in equal probability using only dice5 as a source of random
numbers, and check the distribution for at least one million calls using the fu... | 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... | #Maple | Maple | path := "file.txt":
specificLine := proc(path, num)
local i, input:
for i to num do
input := readline(path):
if input = 0 then break; end if:
end do:
if i = num+1 then printf("Line %d, %s", num, input):
elif i <= num then printf ("Line number %d is not reached",num): end if:
end proc: | Give a code snippet in #Maple
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 i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_variables | Special variables | Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| #Common_Lisp | Common Lisp | (defun special-variables ()
(flet ((special-var-p (s)
(and (char= (aref s 0) #\*)
(find-if-not (lambda (x) (char= x #\*)) s)
(char= (aref s (1- (length s))) #\*))))
(let ((lst '()))
(do-symbols (s (find-package 'cl))
(when (special-var-p (symbol-name s))
... | Give a code snippet in #Common_Lisp
Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| 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... | #AWK | AWK | #
# countsubstring(string, pattern)
# Returns number of occurrences of pattern in string
# Pattern treated as a literal string (regex characters not expanded)
#
function countsubstring(str, pat, len, i, c) {
c = 0
if( ! (len = length(pat) ) )
return 0
while(i = index(str, pat)) {
str = substr(str,... | Give a code snippet in #AWK
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/Create_an_HTML_table | Create an HTML table | Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with sequential row numbers.
The... | #C | C | #include <stdio.h>
#include <stdlib.h>
int main()
{
int i;
printf("<table style=\"text-align:center; border: 1px solid\"><th></th>"
"<th>X</th><th>Y</th><th>Z</th>");
for (i = 0; i < 4; i++) {
printf("<tr><th>%d</th><td>%d</td><td>%d</td><td>%d</td></tr>", i,
rand() % 10000, rand() % 10000, rand() % 10000);... | Give a code snippet in #C
Create an HTML table.
The table body should have at least three rows of three columns.
Each of these three columns should be labelled "X", "Y", and "Z".
An extra column should be added at either the extreme left or the extreme right of the table that has no heading, but is filled with se... | 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
| #PureBasic | PureBasic | IncludeFile "Filename" | Give a code snippet in #PureBasic
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/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Cach.C3.A9_ObjectScript | Caché ObjectScript | EMPTYSTR
; Demonstrate how to assign an empty string to a variable.
set x = ""
; Demonstrate how to check that a string is empty.
; Length 0 is empty; equality/pattern check are 1=T, 0=F
write !,"Assigned x to null value. Tests: "
write !,"String length: "_$length(x)_", Equals null: "... | Give a code snippet in #Cach.C3.A9_ObjectScript
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is... | 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... | #Java | Java | String src = "Hello";
String newAlias = src;
String strCopy = new String(src);
//"newAlias == src" is true
//"strCopy == src" is false
//"strCopy.equals(src)" is true | Give a code snippet in #Java
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 st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Continued_fraction | Continued fraction | continued fraction
Mathworld
a
0
+
b
1
a
1
+
b
2
a
2
+
b
3
a
3
+
⋱
{\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}}
The task is to write a program which generates su... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Function Calc(f As Func(Of Integer, Integer()), n As Integer) As Double
Dim temp = 0.0
For ni = n To 1 Step -1
Dim p = f(ni)
temp = p(1) / (p(0) + temp)
Next
Return f(0)(0) + temp
End Function
Sub Main()
Dim fList = {
... | Give a code snippet in #Visual_Basic_.NET
continued fraction
Mathworld
a
0
+
b
1
a
1
+
b
2
a
2
+
b
3
a
3
+
⋱
{\displaystyle a_{0}+{\cfrac {b_{1}}{a_{1}+{\cfrac {b_{2}}{a_{2}+{\cfrac {b_{3}}{a_{3}+\ddots }}}}}}}
The ta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Text_processing/Max_licenses_in_use | Text processing/Max licenses in use | A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a checkout event when a copy of the ... | #jq | jq | # Input: an array of strings
def max_licenses_in_use:
# state: [in_use = 0, max_in_use = -1, max_in_use_at = [] ]
reduce .[] as $line
([0, -1, [] ];
($line|split(" ")) as $line
| if $line[1] == "OUT" then
.[0] += 1 # in_use++;
| if .[0] > .[1] ... | Give a code snippet in #jq
A company currently pays a fixed sum for the use of a particular licensed software package. In determining if it has a good deal it decides to calculate its maximum use of the software from its license management log file.
Assume the software's licensing daemon faithfully records a checko... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Split_a_character_string_based_on_change_of_character | Split a character string based on change of character |
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly). The same applies
to commas.
Fo... | #Ksh | Ksh |
#!/bin/ksh
# Split a character string based on change of character
# # Variables:
#
str='gHHH5YY++///\'
delim=', '
# # Functions:
#
# # Function _splitonchg(str, delim) - return str split by delim at char change
#
function _splitonchg {
typeset _str ; _str="$1"
typeset _delim ; _delim="$2"
typeset _i _splits... | Give a code snippet in #Ksh
Task
Split a (character) string into comma (plus a blank) delimited
strings based on a change of character (left to right).
Show the output here (use the 1st example below).
Blanks should be treated as any other character (except
they are problematic to display clearly). The ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Non-decimal_radices/Input | Non-decimal radices/Input | It is common to have a string containing a number written in some format, with the most common ones being decimal, hexadecimal, octal and binary. Such strings are found in many places (user interfaces, configuration files, XML data, network protocols, etc.)
This task requires parsing of such a string (which may be ass... | #XPL0 | XPL0 | include c:\cxpl\codes;
int N; real R;
[Text(8, "123_456");
N:= IntIn(8);
IntOut(0, N); CrLf(0);
Text(8, "ABcd12");
N:= HexIn(8);
HexOut(0, N); CrLf(0);
Text(8, "-3.14159e3");
R:= RlIn(8);
RlOut(0, R); CrLf(0);
] | Give a code snippet in #XPL0
It is common to have a string containing a number written in some format, with the most common ones being decimal, hexadecimal, octal and binary. Such strings are found in many places (user interfaces, configuration files, XML data, network protocols, etc.)
This task requires parsing of s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, an... | #PL.2FI | PL/I | short_circuit_evaluation:
procedure options (main);
declare (true initial ('1'b), false initial ('0'b) ) bit (1);
declare (i, j, x, y) bit (1);
a: procedure (bv) returns (bit(1));
declare bv bit(1);
put ('Procedure ' || procedurename() || ' called.');
return (bv);
end a;
b: procedure (bv) returns (b... | Give a code snippet in #PL.2FI
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #Maxima | Maxima | callee(n) := (print(sconcat("called with ", n)), n + 1)$
caller(f, n) := sum(f(i), i, 1, n)$
caller(callee, 3);
"called with 1"
"called with 2"
"called with 3" | Give a code snippet in #Maxima
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #ALGOL_W | ALGOL W | begin % find members of the Harshad/Niven series - numbers divisible by the sum of their digits %
% returns the next member of the series above n %
integer procedure nextHarshad ( integer value n ) ;
begin
integer h, s;
h := n;
while begin
... | Give a code snippet in #ALGOL_W
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The tas... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maze_solving | Maze solving | Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be used.
| #BBC_BASIC | BBC BASIC | MazeWidth% = 11
MazeHeight% = 9
MazeCell% = 50
VDU 23,22,MazeWidth%*MazeCell%/2+3;MazeHeight%*MazeCell%/2+3;8,16,16,128
VDU 23,23,3;0;0;0; : REM Line thickness
OFF
PROCgeneratemaze(Maze&(), MazeWidth%, MazeHeight%, MazeCell%)
PROCsolvemaze(Path{()}, Maze&(), 0, MazeHeig... | Give a code snippet in #BBC_BASIC
Task
For a maze generated by this task, write a function
that finds (and displays) the shortest path between two cells.
Note that because these mazes are generated by the Depth-first search algorithm, they contain no circular paths,
and a simple depth-first tree search can be used... | 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.
| #Euphoria | Euphoria | sequence s1,s2,s3
s1 = {1,2,3}
s2 = {4,5,6}
s3 = s1 & s2
? s3 | Give a code snippet in #Euphoria
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/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... | #Racket | Racket |
#lang racket
;print column of width w
(define (display-col w s)
(let* ([n-spaces (- w (string-length s))]
[spaces (make-string n-spaces #\space)])
(display (string-append s spaces))))
;print columns given widths (idea borrowed from PicoLisp)
(define (tab ws . ss) (for-each display-col ws ss) (newline))... | Give a code snippet in #Racket
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 represe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Long_multiplication | Long multiplication | Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 is:
18,446,744,073,709,551,61... | #PL.2FM | PL/M | 100H: /* LONG MULTIPLICATION OF LARGE INTEGERS */
/* LARGE INTEGERS ARE REPRESENTED BY ARRAYS OF BYTES WHOSE VALUES ARE */
/* A SINGLE DECIMAL DIGIT OF THE NUMBER */
/* THE LEAST SIGNIFICANT DIGIT OF THE LARGE INTEGER IS IN ELEMENT 1 */
... | Give a code snippet in #PL.2FM
Task
Explicitly implement long multiplication.
This is one possible approach to arbitrary-precision integer algebra.
For output, display the result of 264 * 264.
Optionally, verify your result against builtin arbitrary precision support.
The decimal representation of 264 ... | christopher/rosetta-code |
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