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/GUI_enabling/disabling_of_controls | GUI enabling/disabling of controls | In addition to fundamental GUI component interaction, an application should
dynamically enable and disable GUI components, to give some guidance to the
user, and prohibit (inter)actions which are inappropriate in the current state
of the application.
Task
Similar to the task GUI component interaction, write a progr... | #Racket | Racket |
#lang racket/gui
(define frame (new frame% [label "Interaction Demo"]))
(define (changed . _)
(define s (send inp get-value))
(define v (string->number s))
(unless v (set! v (or (string->number (regexp-replace* #rx"[^0-9]+" s "")) 0))
(send inp set-value (~a v)))
(send inc-b enable (< v 10))
... | Give a code snippet in #Racket
In addition to fundamental GUI component interaction, an application should
dynamically enable and disable GUI components, to give some guidance to the
user, and prohibit (inter)actions which are inappropriate in the current state
of the application.
Task
Similar to the task GUI comp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #Racket | Racket | #lang racket/base
;; {trans|Kotlin}}
(define current-width (make-parameter 81))
(define current-height (make-parameter 5))
(define (Cantor_set (w (current-width)) (h (current-height)))
(define lines (build-list h (λ (_) (make-bytes w (char->integer #\#)))))
(define (cantor start len index)
(let* ((seg (qu... | Give a code snippet in #Racket
Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_float_arrays_to_a_text_file | Write float arrays to a text file | Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, 2, 3, 1e11};
y = {1, 1.41421356... | #BASIC256 | BASIC256 | x$ = "1 2 3 1e11"
x$ = explode(x$, " ")
f = freefile
open f, "filename.txt"
for i = 0 to x$[?]-1
writeline f, int(x$[i]) + chr(9) + round(sqrt(x$[i]),4)
next i
close f | Give a code snippet in #BASIC256
Task
Write two equal-sized numerical arrays 'x' and 'y' to
a two-column text file named 'filename'.
The first column of the file contains values from an 'x'-array with a
given 'xprecision', the second -- values from 'y'-array with 'yprecision'.
For example, considering:
x = {1, ... | 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
... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | cocktailSort[A_List] := Module[ { swapped = True },
While[ swapped == True,
swapped=False;
For[ i = 1, i< Length[A]-1,i++,
If[ A[[i]] > A[[i+1]], A[[i;;i+1]] = A[[i+1;;i;;-1]]; swapped=True;]
];
If[swapped == False, Break[]];
swapped=False;
For [ i= Length[A]-1, i > 0, i--,
If[ A[[i]] > A[[i+1]], A[[i;;i+1]] =... | Give a code snippet in #Mathematica.2FWolfram_Language
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 |... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strassen%27s_algorithm | Strassen's algorithm | Description
In linear algebra, the Strassen algorithm (named after Volker Strassen), is an algorithm for matrix multiplication.
It is faster than the standard matrix multiplication algorithm and is useful in practice for large matrices, but would be slower than the fastest known algorithms for extremely large ma... | #Go | Go | package main
import (
"fmt"
"log"
"math"
)
type Matrix [][]float64
func (m Matrix) rows() int { return len(m) }
func (m Matrix) cols() int { return len(m[0]) }
func (m Matrix) add(m2 Matrix) Matrix {
if m.rows() != m2.rows() || m.cols() != m2.cols() {
log.Fatal("Matrices must have the sa... | Give a code snippet in #Go
Description
In linear algebra, the Strassen algorithm (named after Volker Strassen), is an algorithm for matrix multiplication.
It is faster than the standard matrix multiplication algorithm and is useful in practice for large matrices, but would be slower than the fastest known algor... | 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.
| #Tcl | Tcl | oo::define maze {
method solve {} {
### Initialization of visited matrix and location/path queue
set visited [lrepeat $x [lrepeat $y 0]]
set queue {0 0 {}}
### Loop to do the searching ###
while 1 {
# Check for running out of path; an error in maze construction
if {[llength $queue] == 0} {
error ... | Give a code snippet in #Tcl
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/Bulls_and_cows/Player | Bulls and cows/Player | Task
Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts.
One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those numbers that would give an equ... | #Ada | Ada | with Ada.Text_IO;
with Ada.Containers.Vectors;
with Ada.Numerics.Discrete_Random;
procedure Bulls_Player is
-- package for In-/Output of natural numbers
package Nat_IO is new Ada.Text_IO.Integer_IO (Natural);
-- for comparing length of the vectors
use type Ada.Containers.Count_Type;
-- number of ... | Give a code snippet in #Ada
Task
Write a player of the Bulls and Cows game, rather than a scorer. The player should give intermediate answers that respect the scores to previous attempts.
One method is to generate a list of all possible numbers that could be the answer, then to prune the list by keeping only those n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Entropy | Entropy | Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), the Shannon entropy of X in bit... | #zkl | zkl | fcn entropy(text){
text.pump(Void,fcn(c,freq){ c=c.toAsc(); freq[c]+=1; freq }
.fp1( (0).pump(256,List,0.0).copy() )) // array[256] of 0.0
.filter() // remove all zero entries from array
.apply('/(text.len())) // (num of char)/len
.apply(fcn(p){-p*p.log()}) // |p*ln(p)|
.sum(0.0)/(2.0).... | Give a code snippet in #zkl
Task
Calculate the Shannon entropy H of a given input string.
Given the discrete random variable
X
{\displaystyle X}
that is a string of
N
{\displaystyle N}
"symbols" (total characters) consisting of
n
{\displaystyle n}
different characters (n=2 for binary), th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #MAXScript | MAXScript |
fn scan_Nested arr =
(
for subArray in arr where classof subArray == Array do
(
for item in subArray do
(
print item as string
if item == 20 do return OK
)
)
)
| Give a code snippet in #MAXScript
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
i... | 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.
| #REXX | REXX | /*REXX program demonstrates the use of dynamic variable names & setting a val.*/
parse arg newVar newValue
say 'Arguments as they were entered via the command line: ' newVar newValue
say
call value newVar, newValue
say 'The newly assigned value (as per the VALUE bif)------' newVar value(newVar)
... | Give a code snippet in #REXX
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/One_of_n_lines_in_a_file | One of n lines in a file | A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line of the file if possible and m... | #Ruby | Ruby | # Returns a random line from _io_, or nil if _io_ has no lines.
# # Get a random line from /etc/passwd
# line = open("/etc/passwd") {|f| random_line(f) }
def random_line(io)
choice = io.gets; count = 1
while line = io.gets
rand(count += 1).zero? and choice = line
end
choice
end
def one_of_n(n)
# Creat... | Give a code snippet in #Ruby
A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #Delphi | Delphi |
program GElemLIst;
{$IFNDEF FPC}
{$Apptype Console}
{$ENDIF}
uses
math;
const
MaxCnt = 10000;
var
IntArr : array of integer;
fltArr : array of double;
i: integer;
begin
setlength(fltArr,MaxCnt); //filled with 0
setlength(IntArr,MaxCnt); //filled with 0.0
randomize;
i := random(MaxCnt); //ch... | Give a code snippet in #Delphi
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/A%2BB | A+B | A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated by space(s):
(
−
1000
≤... | #Wisp | Wisp |
display : + (read) (read)
314
315
;; displays 629
| Give a code snippet in #Wisp
A+B ─── a classic problem in programming contests, it's given so contestants can gain familiarity with the online judging system being used.
Task
Given two integers, A and B.
Their sum needs to be calculated.
Input data
Two integers are written in the input stream, separated... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Problem_of_Apollonius | Problem of Apollonius |
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straightforward.
The solutions to the ... | #Kotlin | Kotlin | // version 1.1.3
data class Circle(val x: Double, val y: Double, val r: Double)
val Double.sq get() = this * this
fun solveApollonius(c1: Circle, c2: Circle, c3: Circle,
s1: Int, s2: Int, s3: Int): Circle {
val (x1, y1, r1) = c1
val (x2, y2, r2) = c2
val (x3, y3, r3) = c3
va... | Give a code snippet in #Kotlin
Task
Implement a solution to the Problem of Apollonius (description on Wikipedia) which is the problem of finding the circle that is tangent to three specified circles (colored black in the diagram below to the right).
There is an algebraic solution which is pretty straightf... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Median | Averages/Median | Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle values.
There are several approaches ... | #EasyLang | EasyLang | func quickselect k . list[] res .
#
subr partition
swap list[(left + right) / 2] list[left]
mid = left
for i = left + 1 to right
if list[i] < list[left]
mid += 1
swap list[i] list[mid]
.
.
swap list[left] list[mid]
.
left = 0
right = len list[] - 1
while left... | Give a code snippet in #EasyLang
Task[edit]
Write a program to find the median value of a vector of floating-point numbers.
The program need not handle the case where the vector is empty, but must handle the case where there are an even number of elements. In that case, return the average of the two middle valu... | 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... | #Run_BASIC | Run BASIC | dim doors(100)
print "Open doors ";
for i = 1 to 100
for door = i to 100 step i
doors(door) = (doors(door) <> 1)
if i = door and doors(door) = 1 then print i;" ";
next door
next i | Give a code snippet in #Run_BASIC
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/Spiral_matrix | Spiral matrix | Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
15 16 17 18 5
14 23 24 19 6
13 22 21 ... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const type: matrix is array array integer;
const func matrix: spiral (in integer: n) is func
result
var matrix: myArray is matrix.value;
local
var integer: i is 0;
var integer: dx is 1;
var integer: dy is 0;
var integer: x is 1;
var integer: y is 1;
var inte... | Give a code snippet in #Seed7
Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
15 16 17... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_wrap | Word wrap | Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provided in a standard library, sho... | #Forth | Forth | \ wrap text
\ usage: gforth wrap.f in.txt 72
0. argc @ 1- arg >number 2drop drop constant maxLine
: .wrapped ( buf len -- )
begin
dup maxLine >
while
over maxLine
begin 1- 2dup + c@ bl = until
dup 1+ >r
begin 1- 2dup + c@ bl <> until
1+ type cr
r> /string
repeat type cr ;
: stri... | Give a code snippet in #Forth
Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or prov... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #AWK | AWK |
#!/usr/bin/awk -f
function hailstone(v, verbose) {
n = 1;
u = v;
while (1) {
if (verbose) printf " "u;
if (u==1) return(n);
n++;
if (u%2 > 0 )
u = 3*u+1;
else
u = u/2;
}
}
BEGIN {
i = 27;
printf("hailstone(%i) has %i elements\n",i,hailstone(i,1));
ix=0;
m=0;
for (i=1; i<100000; i++) {... | Give a code snippet in #AWK
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
... | 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... | #FutureBasic | FutureBasic | window 1
local fn DecimaltoRoman( decimal as short ) as Str15
short arabic(12)
Str15 roman(12)
long i
Str15 result : result = ""
arabic(0) = 1000 : arabic(1) = 900 : arabic(2) = 500 : arabic(3) = 400
arabic(4) = 100 : arabic(5) = 90 : arabic(6) = 50 : arabic(7) = 40
arabic(8) = 10 : arabic(9) =... | Give a code snippet in #FutureBasic
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_increasing_subsequence | Longest increasing subsequence | Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}}
Note that a list may have m... | #Standard_ML | Standard ML | fun lis cmp n =
let
val pile_tops = DynamicArray.array (length n, [])
fun bsearch_piles x =
let
fun aux (lo, hi) =
if lo > hi then
lo
else
let
val mid = (lo + hi) div 2
in
if cmp (hd (DynamicArray.sub (pile_tops,... | Give a code snippet in #Standard_ML
Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trabb_Pardo%E2%80%93Knuth_algorithm | Trabb Pardo–Knuth algorithm | The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, giving several translations of... | #min | min | ((0 <) (-1 *) when) :abs
(((abs 0.5 pow) (3 pow 5 * +)) cleave) :fn
"Enter 11 numbers:" puts!
(gets float) 11 times
(fn (400 <=) (pop "Overflow") unless puts!) 11 times | Give a code snippet in #min
The TPK algorithm is an early example of a programming chrestomathy.
It was used in Donald Knuth and Luis Trabb Pardo's Stanford tech report The Early Development of Programming Languages.
The report traces the early history of work in developing computer languages in the 1940s and 1950s, g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parameterized_SQL_statement | Parameterized SQL statement | SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don't either. | #Java | Java |
import java.sql.DriverManager;
import java.sql.Connection;
import java.sql.PreparedStatement;
public class DBDemo{
private String protocol; //set this to some connection protocol like "jdbc:sqlserver://"
private String dbName; //set this to the name of your database
private String username;
private St... | Give a code snippet in #Java
SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_common_directory_path | Find common directory path | Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the directory separator and the foll... | #Pike | Pike | array paths = ({ "/home/user1/tmp/coverage/test",
"/home/user1/tmp/covert/operator",
"/home/user1/tmp/coven/members" });
// append a / to each entry, so that a path like "/home/user1/tmp" will be recognized as a prefix
// without it the prefix would end up being "/home/user1/"
paths ... | Give a code snippet in #Pike
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the di... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #Aime | Aime | void
throwing(void)
{
o_text("throwing...\n");
error("now!");
}
void
catching(void)
{
o_text("ready to catch\n");
if (trap(throwing)) {
o_text("caught!\n");
} else {
# nothing was thrown
}
}
integer
main(void)
{
catching();
return 0;
} | Give a code snippet in #Aime
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_format | Date format | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| #8th | 8th |
d:new
"%Y-%M-%D" over d:format . cr
"%W, %N %D, %Y" over d:format . cr
bye
| Give a code snippet in #8th
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Conway%27s_Game_of_Life | Conway's Game of Life | The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, in an m-by-m (or m×m) sq... | #Dart | Dart | /**
* States of a cell. A cell is either [ALIVE] or [DEAD].
* The state contains its [symbol] for printing.
*/
class State {
const State(this.symbol);
static final ALIVE = const State('#');
static final DEAD = const State(' ');
final String symbol;
}
/**
* The "business rule" of the game. Depending on the... | Give a code snippet in #Dart
The Game of Life is a cellular automaton devised by the British mathematician John Horton Conway in 1970. It is the best-known example of a cellular automaton.
Conway's game of life is described here:
A cell C is represented by a 1 when alive, or 0 when dead, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Polymorphism | Polymorphism | Task
Create two classes Point(x,y) and Circle(x,y,r) with a polymorphic function print, accessors for (x,y,r), copy constructor, assignment and destructor and every possible default constructors
| #ActionScript | ActionScript | package
{
public class Point
{
protected var _x:Number;
protected var _y:Number;
public function Point(x:Number = 0, y:Number = 0)
{
_x = x;
_y = y;
}
public function getX():Number
{
return _x;
}
pu... | Give a code snippet in #ActionScript
Task
Create two classes Point(x,y) and Circle(x,y,r) with a polymorphic function print, accessors for (x,y,r), copy constructor, assignment and destructor and every possible default constructors
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Proper_divisors | Proper divisors | The proper divisors of a positive integer N are those numbers, other than N itself, that divide N without remainder.
For N > 1 they will always include 1, but for N == 1 there are no proper divisors.
Examples
The proper divisors of 6 are 1, 2, and 3.
The proper divisors of 100 are 1, 2, 4, 5... | #Frink | Frink |
for n = 1 to 10
println["$n\t" + join[" ", properDivisors[n]]]
println[]
d = new dict
for n = 1 to 20000
{
c = length[properDivisors[n]]
d.addToList[c, n]
}
most = max[keys[d]]
println[d@most + " have $most factors"]
properDivisors[n] := allFactors[n, true, false, true]
| Give a code snippet in #Frink
The proper divisors of a positive integer N are those numbers, other than N itself, that divide N without remainder.
For N > 1 they will always include 1, but for N == 1 there are no proper divisors.
Examples
The proper divisors of 6 are 1, 2, and 3.
The proper divis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_common_directory_path | Find common directory path | Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the directory separator and the foll... | #Tcl | Tcl | package require Tcl 8.5
proc pop {varname} {
upvar 1 $varname var
set var [lassign $var head]
return $head
}
proc common_prefix {dirs {separator "/"}} {
set parts [split [pop dirs] $separator]
while {[llength $dirs]} {
set r {}
foreach cmp $parts elt [split [pop dirs] $separator] {... | Give a code snippet in #Tcl
Create a routine that, given a set of strings representing directory paths and a single character directory separator, will return a string representing that part of the directory tree that is common to all the directories.
Test your routine using the forward slash '/' character as the dir... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #PL.2FI | PL/I | factors: procedure options(main);
declare i binary( 15 )fixed;
declare n binary( 15 )fixed;
do n = 90 to 100;
put skip list( 'factors of: ', n, ': ' );
do i = 1 to n;
if mod(n, i) = 0 then put edit( i )(f(4));
end;
end;
end factors;
| Give a code snippet in #PL.2FI
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/Generate_lower_case_ASCII_alphabet | Generate lower case ASCII alphabet | Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a reliable style of coding, a sty... | #AutoIt | AutoIt |
Func _a2z()
Local $a2z = ""
For $i = 97 To 122
$a2z &= Chr($i)
Next
Return $a2z
EndFunc
| Give a code snippet in #AutoIt
Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Percolation/Mean_cluster_density | Percolation/Mean cluster density |
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
Let
c
{\disp... | #C | C | #include <stdio.h>
#include <stdlib.h>
int *map, w, ww;
void make_map(double p)
{
int i, thresh = RAND_MAX * p;
i = ww = w * w;
map = realloc(map, i * sizeof(int));
while (i--) map[i] = -(rand() < thresh);
}
char alpha[] = "+.ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz";
#define ALEN ((int)(si... | Give a code snippet in #C
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Exponentiation_with_infix_operators_in_(or_operating_on)_the_base | Exponentiation with infix operators in (or operating on) the base | (Many programming languages, especially those with extended─precision integer arithmetic, usually
support one of **, ^, ↑ or some such for exponentiation.)
Some languages treat/honor infix operators when performing exponentiation (raising
numbers to some power by the language's exponentiation operator, if ... | #R | R | expressions <- alist(-x ^ p, -(x) ^ p, (-x) ^ p, -(x ^ p))
x <- c(-5, -5, 5, 5)
p <- c(2, 3, 2, 3)
output <- data.frame(x,
p,
setNames(lapply(expressions, eval), sapply(expressions, deparse)),
check.names = FALSE)
print(output, row.names = FALSE) | Give a code snippet in #R
(Many programming languages, especially those with extended─precision integer arithmetic, usually
support one of **, ^, ↑ or some such for exponentiation.)
Some languages treat/honor infix operators when performing exponentiation (raising
numbers to some power by the language's exp... | 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) .
| #Java | Java | public class Intersection {
private static class Point {
double x, y;
Point(double x, double y) {
this.x = x;
this.y = y;
}
@Override
public String toString() {
return String.format("{%f, %f}", x, y);
}
}
private stati... | Give a code snippet in #Java
[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/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.
| #REXX | REXX | /*REXX program demonstrates detection and handling division by zero. */
signal on syntax /*handle all REXX syntax errors. */
x = sourceline() /*being cute, x=is the size of this pgm*/
y = x - x ... | Give a code snippet in #REXX
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/Simulate_input/Keyboard | Simulate input/Keyboard | Task
Send simulated keystrokes to a GUI window, or terminal.
You should specify whether the target may be externally created
(i.e., if the keystrokes are going to an application
other than the application that is creating them).
| #OCaml | OCaml | ocaml -I +Xlib Xlib.cma keysym.cma send_event.ml
| Give a code snippet in #OCaml
Task
Send simulated keystrokes to a GUI window, or terminal.
You should specify whether the target may be externally created
(i.e., if the keystrokes are going to an application
other than the application that is creating them).
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Convert_decimal_number_to_rational | Convert decimal number to rational | This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It is not always possible to do this... | #Python | Python | >>> from fractions import Fraction
>>> for d in (0.9054054, 0.518518, 0.75): print(d, Fraction.from_float(d).limit_denominator(100))
0.9054054 67/74
0.518518 14/27
0.75 3/4
>>> for d in '0.9054054 0.518518 0.75'.split(): print(d, Fraction(d))
0.9054054 4527027/5000000
0.518518 259259/500000
0.75 3/4
>>> | Give a code snippet in #Python
This task has been flagged for clarification. Code on this page in its current state may be flagged incorrect once this task has been clarified. See this page's Talk page for discussion.
The task is to write a program to transform a decimal number into a fraction in lowest terms.
It i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Summarize_and_say_sequence | Summarize and say sequence | There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 311311222110 ...
The terms generat... | #CLU | CLU | summarize = proc (s: string) returns (string) signals (bad_format)
digit_count: array[int] := array[int]$fill(0,10,0)
for c: char in string$chars(s) do
d: int := int$parse(string$c2s(c)) resignal bad_format
digit_count[d] := digit_count[d] + 1
end
out: stream := stream$create_output()
... | Give a code snippet in #CLU
There are several ways to generate a self-referential sequence. One very common one (the Look-and-say sequence) is to start with a positive integer, then generate the next term by concatenating enumerated groups of adjacent alike digits:
0, 10, 1110, 3110, 132110, 1113122110, 311311... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parameterized_SQL_statement | Parameterized SQL statement | SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don't either. | #Perl | Perl | use DBI;
my $db = DBI->connect('DBI:mysql:mydatabase:host','login','password');
$statment = $db->prepare("UPDATE players SET name = ?, score = ?, active = ? WHERE jerseyNum = ?");
$rows_affected = $statment->execute("Smith, Steve",42,'true',99); | Give a code snippet in #Perl
SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Merge_sort | Sorting algorithms/Merge sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #OCaml | OCaml | let rec split_at n xs =
match n, xs with
0, xs ->
[], xs
| _, [] ->
failwith "index too large"
| n, x::xs when n > 0 ->
let xs', xs'' = split_at (pred n) xs in
x::xs', xs''
| _, _ ->
invalid_arg "negative argument"
let rec merge_sort cmp = function
[] ... | Give a code snippet in #OCaml
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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.
... | #Retro | Retro | 6 [ 0; cr [ '* emit ] times ] iter | Give a code snippet in #Retro
“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 structu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Animation | Animation |
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task demonstrates this.
Task
Creat... | #Rust | Rust | #[cfg(feature = "gtk")]
mod graphical {
extern crate gtk;
use self::gtk::traits::*;
use self::gtk::{Inhibit, Window, WindowType};
use std::ops::Not;
use std::sync::{Arc, RwLock};
pub fn create_window() {
gtk::init().expect("Failed to initialize GTK");
let window = Window::n... | Give a code snippet in #Rust
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task dem... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_name | Program name | The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script name to a language's internal A... | #Yabasic | Yabasic | print peek$("program_name")
s$ = system$("cd")
n = len(s$)
print left$(s$, n - 2), "\\", peek$("program_name") | Give a code snippet in #Yabasic
The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the scrip... | 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... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | suffixlist = {"th", "st", "nd", "rd", "th", "th", "th", "th", "th","th"};
addsuffix[n_] := Module[{suffix},
suffix = Which[
Mod[n, 100] <= 10, suffixlist[[Mod[n, 10] + 1]],
Mod[n, 100] > 20, suffixlist[[Mod[n, 10] + 1]],
True, "th"
];
ToString[n] <> suffix
]
addsuffix[#] & /@ Range[0, 25] (* test ... | Give a code snippet in #Mathematica.2FWolfram_Language
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
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Partition_an_integer_x_into_n_primes | Partition an integer x into n primes | Task
Partition a positive integer X into N distinct primes.
Or, to put it in another way:
Find N unique primes such that they add up to X.
Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs:
• partition 99809 with 1 prime.
... | #C.2B.2B | C++ | #include <algorithm>
#include <functional>
#include <iostream>
#include <vector>
std::vector<int> primes;
struct Seq {
public:
bool empty() {
return p < 0;
}
int front() {
return p;
}
void popFront() {
if (p == 2) {
p++;
} else {
p += 2... | Give a code snippet in #C.2B.2B
Task
Partition a positive integer X into N distinct primes.
Or, to put it in another way:
Find N unique primes such that they add up to X.
Show in the output section the sum X and the N primes in ascending order separated by plus (+) signs:
• parti... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_totient_numbers | Perfect totient numbers | Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| #C.2B.2B | C++ | #include <cassert>
#include <iostream>
#include <vector>
class totient_calculator {
public:
explicit totient_calculator(int max) : totient_(max + 1) {
for (int i = 1; i <= max; ++i)
totient_[i] = i;
for (int i = 2; i <= max; ++i) {
if (totient_[i] < i)
conti... | Give a code snippet in #C.2B.2B
Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_random_chess_position | Generate random chess position | Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacent squares;
there can not be any p... | #J | J | getlayout=:3 :0
whilst. NB. first two positions are non-adjacent kings
(0{pos) e. (1{pos)+(,-)1 7 8 9
do.
pos=: y?64
end.
)
randboard=:3 :0
n=: ?30 NB. number of non-king pieces on board
layout=: getlayout 2+n NB. where they go
white=: 0 1,?n#2 NB. which ones are white?
pawns=: 0 0,?n... | Give a code snippet in #J
Task
Generate a random chess position in FEN format.
The position does not have to be realistic or even balanced, but it must comply to the following rules:
there is one and only one king of each color (one black king and one white king);
the kings must not be placed on adjacent squar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #Java | Java | import java.math.BigDecimal;
import java.math.BigInteger;
import java.math.MathContext;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
public class EgyptianFractions {
private static BigInteger gcd(BigInteger a, BigInteger b) {
if (b.equals(BigInteger.ZERO)) {
... | Give a code snippet in #Java
An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (u... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_subsequential_sum | Greatest subsequential sum | Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elements are negative, the result must be th... | #Ada | Ada | with Ada.Text_Io; use Ada.Text_Io;
procedure Max_Subarray is
type Int_Array is array (Positive range <>) of Integer;
Empty_Error : Exception;
function Max(Item : Int_Array) return Int_Array is
Start : Positive;
Finis : Positive;
Max_Sum : Integer := Integer'First;
Sum : Integer;
be... | Give a code snippet in #Ada
Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elements are ne... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Date_format | Date format | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| #HicEst | HicEst | CHARACTER string*40
WRITE(Text=string, Format='UCCYY-MM-DD') 0 ! string: 2010-03-13
! the U-format to write date and time uses ',' to separate additional output formats
! we therefore use ';' in this example and change it to ',' below:
WRITE(Text=string,Format='UWWWWWWWWW; MM DD; CCYY') 0 ! string = ... | Give a code snippet in #HicEst
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Task
Display the current date in the formats of:
2007-11-23 and
Friday, November 23, 2007
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Ordered_words | Ordered words | An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locally assume that you have download... | #Picat | Picat | go =>
Dict = "unixdict.txt",
Words = new_map([Word=Word.length : Word in read_file_lines(Dict), Word == Word.sort()]),
MaxLen = max([Len : _Word=Len in Words]),
println([Word : Word=Len in Words, Len=MaxLen].sort). | Give a code snippet in #Picat
An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locall... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #Vedit_macro_language | Vedit macro language | Get_Environment(10,"PATH")
Message(@10) | Give a code snippet in #Vedit_macro_language
Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Miller%E2%80%93Rabin_primality_test | Miller–Rabin primality test |
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primality test or Rabin–Miller prima... | #Swift | Swift | import BigInt
private let numTrails = 5
func isPrime(_ n: BigInt) -> Bool {
guard n >= 2 else { fatalError() }
guard n != 2 else { return true }
guard n % 2 != 0 else { return false }
var s = 0
var d = n - 1
while true {
let (quo, rem) = (d / 2, d % 2)
guard rem != 1 else { break }
s... | Give a code snippet in #Swift
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin prima... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Oberon-2 | Oberon-2 | MODULE Primes;
IMPORT Out, Math;
CONST N = 1000;
VAR a: ARRAY N OF BOOLEAN;
i, j, m: INTEGER;
BEGIN
(* Set all elements of a to TRUE. *)
FOR i := 1 TO N - 1 DO
a[i] := TRUE;
END;
(* Compute square root of N and convert back to INTEGER. *)
m := ENTIER(Math.Sqrt(N));
FOR... | Give a code snippet in #Oberon-2
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Joystick_position | Joystick position | The task is to determine the joystick position and represent this on the display via a crosshair.
For a centred joystick, the crosshair should appear in the centre of the screen.
If the joystick is pushed left or right, then the cross hair should move left or right according to the extent that the joystick is pushed.
... | #Delphi | Delphi |
unit uMain;
interface
uses
Winapi.Windows, System.SysUtils, System.Classes, Vcl.Controls, Vcl.Forms,
Vcl.ExtCtrls, Vcl.StdCtrls;
type
TForm1 = class(TForm)
tmr1: TTimer;
lblPosition: TLabel;
procedure tmr1Timer(Sender: TObject);
procedure FormPaint(Sender: TObject);
private
{ Private... | Give a code snippet in #Delphi
The task is to determine the joystick position and represent this on the display via a crosshair.
For a centred joystick, the crosshair should appear in the centre of the screen.
If the joystick is pushed left or right, then the cross hair should move left or right according to the exten... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/DOM_serialization | XML/DOM serialization | Create a simple DOM and having it serialize to:
<?xml version="1.0" ?>
<root>
<element>
Some text here
</element>
</root>
| #Rascal | Rascal | import lang::xml::DOM;
public void main(){
x = document(element(none(), "root", [element(none(), "element", [charData("Some text here")])]));
return println(xmlPretty(x));
} | Give a code snippet in #Rascal
Create a simple DOM and having it serialize to:
<?xml version="1.0" ?>
<root>
<element>
Some text here
</element>
</root>
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_pixel | Draw a pixel | Task
Create a window and draw a pixel in it, subject to the following:
the window is 320 x 240
the color of the pixel must be red (255,0,0)
the position of the pixel is x = 100, y = 100 | #VBA | VBA | Sub draw()
Dim sh As Shape, sl As Shape
Set sh = ActiveDocument.Shapes.AddCanvas(100, 100, 320, 240)
Set sl = sh.CanvasItems.AddLine(100, 100, 101, 100)
sl.Line.ForeColor.RGB = RGB(Red:=255, Green:=0, Blue:=0)
End Sub | Give a code snippet in #VBA
Task
Create a window and draw a pixel in it, subject to the following:
the window is 320 x 240
the color of the pixel must be red (255,0,0)
the position of the pixel is x = 100, y = 100 | christopher/rosetta-code | |
http://rosettacode.org/wiki/Image_convolution | Image convolution | One class of image digital filters is described by a rectangular matrix of real coefficients called kernel convoluted in a sliding window of image pixels. Usually the kernel is square
K
k
l
{\displaystyle K_{kl}}
, where k, l are in the range -R,-R+1,..,R-1,R. W=2R+1 is the kernel width. The filter determine... | #Liberty_BASIC | Liberty BASIC |
dim result( 300, 300), image( 300, 300), mask( 100, 100)
w =128
h =128
nomainwin
WindowWidth = 460
WindowHeight = 210
open "Convolution" for graphics_nsb_nf as #w
#w "trapclose [quit]"
#w "down ; fill darkblue"
hw = hwnd( #w)
calldll #user32,"GetDC", hw as ulon... | Give a code snippet in #Liberty_BASIC
One class of image digital filters is described by a rectangular matrix of real coefficients called kernel convoluted in a sliding window of image pixels. Usually the kernel is square
K
k
l
{\displaystyle K_{kl}}
, where k, l are in the range -R,-R+1,..,R-1,R. W=2R+1 is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Evaluate_binomial_coefficients | Evaluate binomial coefficients | This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(
n
−
2
)
…
(
n
−
k
+
1
)
k
(
k
−
1... | #JavaScript | JavaScript | function binom(n, k) {
var coeff = 1;
var i;
if (k < 0 || k > n) return 0;
for (i = 0; i < k; i++) {
coeff = coeff * (n - i) / (i + 1);
}
return coeff;
}
console.log(binom(5, 3)); | Give a code snippet in #JavaScript
This programming task, is to calculate ANY binomial coefficient.
However, it has to be able to output
(
5
3
)
{\displaystyle {\binom {5}{3}}}
, which is 10.
This formula is recommended:
(
n
k
)
=
n
!
(
n
−
k
)
!
k
!
=
n
(
n
−
1
)
(... | 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... | #Perl | Perl | use List::Util 'max';
my ($w, $h) = @ARGV;
$w ||= 26;
$h ||= 127;
my $avail = $w * $h;
# cell is padded by sentinel col and row, so I don't check array bounds
my @cell = (map([(('1') x $w), 0], 1 .. $h), [('') x ($w + 1)]);
my @ver = map([("| ") x $w], 1 .. $h);
my @hor = map([("+--") x $w], 0 .. $h);
sub walk {... | Give a code snippet in #Perl
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Priority_queue | Priority queue | A priority queue is somewhat similar to a queue, with an important distinction: each item is added to a priority queue with a priority level, and will be later removed from the queue with the highest priority element first. That is, the items are (conceptually) stored in the queue in priority order instead of in insert... | #Zig | Zig |
const std = @import("std");
const PriorityQueue = std.PriorityQueue;
const Allocator = std.mem.Allocator;
const testing = std.testing;
/// wrapper for the task - stores task priority
/// along with the task name
const Task = struct {
const Self = @This();
priority: i32,
name: []const u8,
pub fn ... | Give a code snippet in #Zig
A priority queue is somewhat similar to a queue, with an important distinction: each item is added to a priority queue with a priority level, and will be later removed from the queue with the highest priority element first. That is, the items are (conceptually) stored in the queue in priori... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list | Search a list | Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that has multiple occurrences in ... | #Tcl | Tcl | set haystack {Zig Zag Wally Ronald Bush Krusty Charlie Bush Bozo}
foreach needle {Bush Washington} {
if {[set idx [lsearch -exact $haystack $needle]] == -1} {
error "$needle does not appear in the haystack"
} else {
puts "$needle appears at index $idx in the haystack"
}
} | Give a code snippet in #Tcl
Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #J | J | enum =: cocreate''
( (;:'apple banana cherry') ,L:0 '__enum' ) =: i. 3
cherry__enum
2 | Give a code snippet in #J
Task
Create an enumeration of constants with and without explicit values.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/String_concatenation | String concatenation | String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another string literal.
To illustrate the operat... | #Plain_English | Plain English | To run:
Start up.
Put "hello" into a string.
Put the string then " world" into another string.
Write the string to the console.
Write the other string to the console.
Wait for the escape key.
Shut down. | Give a code snippet in #Plain_English
String concatenation
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a string variable equal to any text value.
Create another string variable whose value is the original variable concatenated with another st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_and_permutations | Combinations and permutations |
This page uses content from Wikipedia. The original article was at Combination. 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)
This page uses content from Wikipedia. The original article was at P... | #Factor | Factor | USING: math.combinatorics prettyprint ;
1000 10 nCk . ! 263409560461970212832400
1000 10 nPk . ! 955860613004397508326213120000 | Give a code snippet in #Factor
This page uses content from Wikipedia. The original article was at Combination. 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)
This page uses content from Wikipedi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generator/Exponential | Generator/Exponential | A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that the internal state of the objec... | #F.23 | F# | let m n = Seq.unfold(fun i -> Some(bigint.Pow(i, n), i + 1I)) 0I
let squares = m 2
let cubes = m 3
let (--) orig veto = Seq.where(fun n -> n <> (Seq.find(fun m -> m >= n) veto)) orig
let ``squares without cubes`` = squares -- cubes
Seq.take 10 (Seq.skip 20 (``squares without cubes``))
|> Seq.toList |> printfn "... | Give a code snippet in #F.23
A generator is an executable entity (like a function or procedure) that contains code that yields a sequence of values, one at a time, so that each time you call the generator, the next value in the sequence is provided.
Generators are often built on top of coroutines or objects so that t... | 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 ... | #Julia | Julia | e
π, pi
sqrt(x)
log(x)
exp(x)
abs(x)
floor(x)
ceil(x)
x^y | Give a code snippet in #Julia
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. "m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Object_serialization | Object serialization | Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write each of the objects to a file named o... | #Objeck | Objeck |
bundle Default {
class Thingy {
@id : Int;
New(id : Int) {
@id := id;
}
method : public : Print() ~ Nil {
@id->PrintLine();
}
}
class Person from Thingy {
@name : String;
New(id : Int, name : String) {
Parent(id);
@name := name;
}
method : pu... | Give a code snippet in #Objeck
Create a set of data types based upon inheritance. Each data type or class should have a print command that displays the contents of an instance of that class to standard output. Create instances of each class in your inheritance hierarchy and display them to standard output. Write each ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Square_but_not_cube | Square but not cube | Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| #Common_Lisp | Common Lisp | (defun cubep (n)
(loop for i from 1
for c = (* i i i)
while (<= c n)
when (= c n) do (return t)
finally (return nil)))
(defparameter squares (let ((n 0)) (lambda () (incf n) (* n n))))
(destructuring-bind (noncubes cubes)
(loop for s = (funcall squares) then (funcall square... | Give a code snippet in #Common_Lisp
Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Subleq | Subleq | Subleq is an example of a One-Instruction Set Computer (OISC).
It is named after its only instruction, which is SUbtract and Branch if Less than or EQual to zero.
Task
Your task is to create an interpreter which emulates a SUBLEQ machine.
The machine's memory consists of an array of signed integers. These integers... | #Objeck | Objeck | use System.IO;
class Sublet {
function : Main(args : String[]) ~ Nil {
mem := [
15, 17, -1, 17, -1, -1, 16, 1, -1, 16,
3, -1, 15, 15, 0, 0, -1, 72, 101, 108,
108, 111, 44, 32, 119, 111, 114, 108, 100, 33,
10, 0];
instructionPointer := 0;
do {
a := mem[instructionPointer... | Give a code snippet in #Objeck
Subleq is an example of a One-Instruction Set Computer (OISC).
It is named after its only instruction, which is SUbtract and Branch if Less than or EQual to zero.
Task
Your task is to create an interpreter which emulates a SUBLEQ machine.
The machine's memory consists of an array of s... | 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... | #RapidQ | RapidQ | DIM angle AS Double
DIM x AS Double, y AS Double
DECLARE SUB PaintCanvas
CREATE form AS QForm
Width = 800
Height = 600
CREATE canvas AS QCanvas
Height = form.ClientHeight
Width = form.ClientWidth
OnPaint = PaintCanvas
END CREATE
END CREATE
SUB turn (degrees AS Double)
... | Give a code snippet in #RapidQ
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 b... | 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... | #F.23 | F# | let value = "100"
let fromBases = [ 2; 8; 10; 16 ]
let values = Seq.initInfinite (fun i -> value)
Seq.zip fromBases (Seq.zip values fromBases |> Seq.map (System.Convert.ToInt32))
|> Seq.iter (
fun (fromBase, valueFromBaseX) ->
printfn "%s in base %i is %i in base 10" value fromBase valueFromBaseX) | Give a code snippet in #F.23
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/Straddling_checkerboard | Straddling checkerboard | Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a series of decimal digits.
Num... | #C.23 | C# | using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
namespace StraddlingCheckerboard
{
class Program
{
public readonly static IReadOnlyDictionary<char, string> val2Key;
public readonly static IReadOnlyDictionary<string, char> key2Val;
... | Give a code snippet in #C.23
Task
Implement functions to encrypt and decrypt a message using the straddling checkerboard method. The checkerboard should take a 28 character alphabet (A-Z plus a full stop and an escape character) and two different numbers representing the blanks in the first row. The output will be a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_common_substring | Longest common substring | Task
Write a function that returns the longest common substring of two strings.
Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing".
Note that substrings are consecutive characters within a string.... | #Rust | Rust | fn longest_common_substring(s1: &str, s2: &str) -> String {
let s1_chars: Vec<char> = s1.chars().collect();
let s2_chars: Vec<char> = s2.chars().collect();
let mut lcs = "".to_string();
for i in 0..s1_chars.len() {
for j in 0..s2_chars.len() {
if s1_chars[i] == s2_chars[j] {
... | Give a code snippet in #Rust
Task
Write a function that returns the longest common substring of two strings.
Use it within a program that demonstrates sample output from the function, which will consist of the longest common substring between "thisisatest" and "testing123testing".
Note that substrings are consecuti... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SEDOLs | SEDOLs | Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842
B0YBKT7
B000300
Extra credit
... | #COBOL | COBOL | >>SOURCE FREE
IDENTIFICATION DIVISION.
PROGRAM-ID. sedol.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
FILE-CONTROL.
SELECT sedol-file ASSIGN "sedol.txt"
ORGANIZATION LINE SEQUENTIAL
FILE STATUS sedol-file-status.
DATA DIVISION.
FILE SECTION.
FD sedol-file.
01 sedol ... | Give a code snippet in #COBOL
Task
For each number list of 6-digit SEDOLs, calculate and append the checksum digit.
That is, given this input:
710889
B0YBKJ
406566
B0YBLH
228276
B0YBKL
557910
B0YBKR
585284
B0YBKT
B00030
Produce this output:
7108899
B0YBKJ7
4065663
B0YBLH2
2282765
B0YBKL9
5579107
B0YBKR5
5852842... | 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... | #ALGOL_68 | ALGOL 68 | #!/usr/local/bin/a68g --script #
REAL r = 20 000/pi + 6.6 # km #,
to rad = pi/180;
PROC dist = (REAL th1 deg, ph1 deg, th2 deg, ph2 deg)REAL:
(
REAL ph1 = (ph1 deg - ph2 deg) * to rad,
th1 = th1 deg * to rad, th2 = th2 deg * to rad,
dz = sin(th1) - sin(th2),
dx ... | Give a code snippet in #ALGOL_68
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/Integer_sequence | Integer sequence | Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations limits. For example, if integer... | #Frink | Frink |
i=0
while true
{
println[i]
i = i + 1
}
| Give a code snippet in #Frink
Task
Create a program that, when run, would display all integers from 1 to ∞ (or any relevant implementation limit), in sequence (i.e. 1, 2, 3, 4, etc) if given enough time.
An example may not be able to reach arbitrarily-large numbers based on implementations li... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Primality_by_trial_division | Primality by trial division | Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other loops are allowed.
Related tasks
... | #Quackery | Quackery | [ dup 4 < iff [ 1 > ] done
dup 1 & not iff [ drop false ] done
true swap dup sqrt
0 = iff [ 2drop not ] done
1 >> times
[ dup i^ 1 << 3 + mod 0 = if
[ dip not conclude ] ]
drop ] is isprime ( n --> b )
| Give a code snippet in #Quackery
Task
Write a boolean function that tells whether a given integer is prime.
Remember that 1 and all non-positive numbers are not prime.
Use trial division.
Even numbers greater than 2 may be eliminated right away.
A loop from 3 to √ n will suffice, but other lo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #Liberty_BASIC | Liberty BASIC | ' [RC] Luhn test
card$(1)="49927398716"
card$(2)="49927398717"
card$(3)="1234567812345678"
card$(4)="1234567812345670"
for test = 1 to 4
odd=1
sum = 0
for n = len(card$(test)) to 1 step -1
num=val(mid$(card$(test),n,1))
if odd then
sum = sum + num
odd=0
el... | Give a code snippet in #Liberty_BASIC
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #Nanoquery | Nanoquery | def isNum(str)
try
double(str)
return true
catch
return false
end
end | Give a code snippet in #Nanoquery
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metric... | 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... | #EasyLang | EasyLang | txt$ = "sos sos"
#
chars$[] = strchars "abcdefghijklmnopqrstuvwxyz "
code$[] = [ ".-" "-..." "-.-." "-.." "." "..-." "--." "...." ".." ".---" "-.-" ".-.." "--" "-." "---" ".--." "--.-" ".-." "..." "-" "..-" "...-" ".--" "-..-" "-.--" "--.." " " ]
#
func morse ch$ . .
while ind < len chars$[] and chars$[ind] <> ch$
... | Give a code snippet in #EasyLang
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/Terminal_control/Hiding_the_cursor | Terminal control/Hiding the cursor | The task is to hide the cursor and show it again.
| #PicoLisp | PicoLisp | (call "tput" "civis") # Invisible
(wait 1000)
(call "tput" "cvvis") # Visible | Give a code snippet in #PicoLisp
The task is to hide the cursor and show it again.
| 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... | #PL.2FI | PL/I | declare N fixed binary;
get edit (N) (A(7)); /* decimal input of 7 columns */
put skip list (N);
declare BS bit (32);
get edit (BS) (B(32)); /* Binary input of 32 binary digits. */
put skip edit (BS) (B); | Give a code snippet in #PL.2FI
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_name | Program name | The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the script name to a language's internal A... | #Euphoria | Euphoria | constant cmd = command_line()
puts(1,cmd[2]) | Give a code snippet in #Euphoria
The task is to programmatically obtain the name used to invoke the program. (For example determine whether the user ran "python hello.py", or "python hellocaller.py", a program importing the code from "hello.py".)
Sometimes a multiline shebang is necessary in order to provide the scri... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Langton%27s_ant | Langton's ant | Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the following rules:
If the ce... | #bc | bc | define o() {
auto i, j
"P1 "
w
h
for (j = 0; j < h; j++) {
for (i = 0; i < w; i++) {
a[j * w + i]
}
}
}
define l(w, h, x, y) {
auto a[], d, i, x[], y[]
/* d represents one of the four possible directions:
* 0
* ⇑
* ... | Give a code snippet in #bc
Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the fo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fractal_tree | Fractal tree | Generate and draw a fractal tree.
Draw the trunk
At the end of the trunk, split by some angle and draw two branches
Repeat at the end of each branch until a sufficient level of branching is reached
Related tasks
Pythagoras Tree
| #Fantom | Fantom |
using fwt
using gfx
class FractalCanvas : Canvas
{
new make () : super() {}
Void drawTree (Graphics g, Int x1, Int y1, Int angle, Int depth)
{
if (depth == 0) return
Int x2 := x1 + (angle.toFloat.toRadians.cos * depth * 10.0).toInt;
Int y2 := y1 + (angle.toFloat.toRadians.sin * depth * 10.0).to... | Give a code snippet in #Fantom
Generate and draw a fractal tree.
Draw the trunk
At the end of the trunk, split by some angle and draw two branches
Repeat at the end of each branch until a sufficient level of branching is reached
Related tasks
Pythagoras Tree
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_reversal_game | Number reversal game | Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The score is the count of the reversa... | #BBC_BASIC | BBC BASIC | DIM list%(8), done%(8), test%(8)
list%() = 1, 2, 3, 4, 5, 6, 7, 8, 9
done%() = list%()
REM Shuffle:
REPEAT
FOR i% = 9 TO 2 STEP -1
SWAP list%(i%-1), list%(RND(i%)-1)
NEXT
test%() = list%() - done%()
UNTIL MOD(test%()) <> 0
REM Run the game:... | Give a code snippet in #BBC_BASIC
Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
Th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_number_divisible_by_its_digits | Largest number divisible by its digits | Task
Find the largest base 10 integer whose digits are all different, and is evenly divisible by each of its individual digits.
These numbers are also known as Lynch-Bell numbers, numbers n such that the
(base ten) digits are all different (and do not include zero) and n is divisible by each of it... | #Sidef | Sidef | func largest_number(base) {
var digits = @(base ^.. 1)
digits.each {|k|
digits.variations(k, {|*a|
var n = Number(a.join, base)
if (a.all {|d| d.divides(n) }) {
return n
}
})
}
}
say largest_number(10) #=> 9867312 | Give a code snippet in #Sidef
Task
Find the largest base 10 integer whose digits are all different, and is evenly divisible by each of its individual digits.
These numbers are also known as Lynch-Bell numbers, numbers n such that the
(base ten) digits are all different (and do not include zero) and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Middle-square_method | Pseudo-random numbers/Middle-square method | Middle-square_method Generator
The Method
To generate a sequence of n-digit pseudorandom numbers, an n-digit starting value is created and squared, producing a 2n-digit number. If the result has fewer than 2n digits, leading zeroes are added to compensate. The middle n digits of the result would be the next number i... | #uBasic.2F4tH | uBasic/4tH | If Info("wordsize") < 64 Then Print "This needs a 64-bit uBasic" : End
s = 675248
For i = 1 To 5
Print Set(s, FUNC(_random(s)))
Next
End
_random Param (1) : Return (a@*a@/1000%1000000) | Give a code snippet in #uBasic.2F4tH
Middle-square_method Generator
The Method
To generate a sequence of n-digit pseudorandom numbers, an n-digit starting value is created and squared, producing a 2n-digit number. If the result has fewer than 2n digits, leading zeroes are added to compensate. The middle n digits of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Wilson_primes_of_order_n | Wilson primes of order n | Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
Task
Calculate and show on thi... | #Wren | Wren | import "/math" for Int
import "/big" for BigInt
import "/fmt" for Fmt
var limit = 11000
var primes = Int.primeSieve(limit)
var facts = List.filled(limit, null)
facts[0] = BigInt.one
for (i in 1...11000) facts[i] = facts[i-1] * i
var sign = 1
System.print(" n: Wilson primes")
System.print("--------------------")
for ... | Give a code snippet in #Wren
Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
... | 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... | #Rust | Rust |
use std::iter;
// Calculating a continued fraction is quite easy with iterators, however
// writing a proper iterator adapter is less so. We settle for a macro which
// for most purposes works well enough.
//
// One limitation with this iterator based approach is that we cannot reverse
// input iterators since they... | Give a code snippet in #Rust
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 writ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/State_name_puzzle | State name puzzle | Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearrange the letters to form the... | #J | J | require'strings stats'
states=:<;._2]0 :0-.LF
Alabama,Alaska,Arizona,Arkansas,California,Colorado,
Connecticut,Delaware,Florida,Georgia,Hawaii,Idaho,
Illinois,Indiana,Iowa,Kansas,Kentucky,Louisiana,
Maine,Maryland,Massachusetts,Michigan,Minnesota,
Mississippi,Missouri,Montana,Nebraska,Nevada,
New Hampshire,New Jers... | Give a code snippet in #J
Background
This task is inspired by Mark Nelson's DDJ Column "Wordplay" and one of the weekly puzzle challenges from Will Shortz on NPR Weekend Edition [1] and originally attributed to David Edelheit.
The challenge was to take the names of two U.S. States, mix them all together, then rearra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reflection/Get_source | Reflection/Get source | Task
The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
| #JavaScript | JavaScript | function foo() {...}
foo.toString();
// "function foo() {...}"
| Give a code snippet in #JavaScript
Task
The goal is to get the source code or file path and line number where a programming object (e.g. module, class, function, method) is defined.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiple_distinct_objects | Multiple distinct objects | Create a sequence (array, list, whatever) consisting of n distinct, initialized items of the same type. n should be determined at runtime.
By distinct we mean that if they are mutable, changes to one do not affect all others; if there is an appropriate equality operator they are considered unequal; etc. The code need ... | #XPL0 | XPL0 | code Reserve=3, IntIn=10;
char A; int N, I;
[N:= IntIn(8); \get number of items from command line
A:= Reserve(N); \create array of N bytes
for I:= 0 to N-1 do A(I):= I*3; \initialize items with different values
for I:= 0 to N-1 do A:= I*3; \error: "references to the same mutable ... | Give a code snippet in #XPL0
Create a sequence (array, list, whatever) consisting of n distinct, initialized items of the same type. n should be determined at runtime.
By distinct we mean that if they are mutable, changes to one do not affect all others; if there is an appropriate equality operator they are considere... | christopher/rosetta-code | |
http://rosettacode.org/wiki/System_time | System time | Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
Date format
See also
Retr... | #Gambas | Gambas | Public Sub Main()
Print Format(Now, "dddd dd mmmm yyyy hh:nn:ss")
End | Give a code snippet in #Gambas
Task
Output the system time (any units will do as long as they are noted) either by a system command or one built into the language.
The system time can be used for debugging, network information, random number seeds, or something as simple as program performance.
Related task
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_has_all_the_same_characters | Determine if a string has all the same characters | Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are the same
indicate if or which character is different from the previous character
display each string and its length (as the... | #OCaml | OCaml |
(* Task: Determine if a string has all the same characters *)
(* Create a function that determines whether all characters in a string are identical,
or returns the index of first different character.
Using the option type here to combine the functionality.
*)
let str_first_diff_char (s : string) : int o... | Give a code snippet in #OCaml
Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are the same
indicate if or which character is different from the previous character
display each ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Yin_and_yang | Yin and yang | One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
| #UNIX_Shell | UNIX Shell | #!/usr/bin/env bash
in_circle() { #(cx, cy, r, x y)
# return true if the point (x,y) lies within the circle of radius r centered
# on (cx,cy)
# (but really scaled to an ellipse with vertical minor semiaxis r and
# horizontal major semiaxis 2r)
local -i cx=$1 cy=$2 r=$3 x=$4 y=$5
local -i dx dy
(( dx=(x-cx... | Give a code snippet in #UNIX_Shell
One well-known symbol of the philosophy of duality known as yin and yang is the taijitu.
Task
Create a function that, given a parameter representing size, generates such a symbol scaled to the requested size.
Generate and display the symbol for two different (small) sizes.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #K | K | _ic "abcABC"
97 98 99 65 66 67
_ci 97 98 99 65 66 67
"abcABC" | Give a code snippet in #K
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Converse... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #Ruby | Ruby | values.max | Give a code snippet in #Ruby
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| christopher/rosetta-code |
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