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/Write_entire_file | Write entire file | Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| #C | C | /*
* Write Entire File -- RossetaCode -- dirty hackish solution
*/
#define _CRT_SECURE_NO_WARNINGS // turn off MS Visual Studio restrictions
#include <stdio.h>
int main(void)
{
return 0 >= fputs("ANY STRING TO WRITE TO A FILE AT ONCE.",
freopen("sample.txt","wb",stdout));
}
| Give a code snippet in #C
Task
(Over)write a file so that it contains a string.
The reverse of Read entire file—for when you want to update or create a file which you would read in its entirety all at once.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Return_multiple_values | Return multiple values | Task
Show how to return more than one value from a function.
| #F.C5.8Drmul.C3.A6 | Fōrmulæ | func addsub(x, y int) (int, int) {
return x + y, x - y
} | Give a code snippet in #F.C5.8Drmul.C3.A6
Task
Show how to return more than one value from a function.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Pick_random_element | Pick random element | Demonstrate how to pick a random element from a list.
| #ReScript | ReScript | let fruits = ["apple", "banana", "coconut", "orange", "lychee"]
let pickRand = arr => {
let len = Js.Array.length(arr)
let i = Js.Math.random_int(0, len)
arr[i]
}
Js.log(pickRand(fruits)) | Give a code snippet in #ReScript
Demonstrate how to pick a random element from a list.
| 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 ... | #Objeck | Objeck |
use Structure;
bundle Default {
class Median {
function : Main(args : String[]) ~ Nil {
numbers := FloatVector->New([4.1, 5.6, 7.2, 1.7, 9.3, 4.4, 3.2]);
DoMedian(numbers)->PrintLine();
numbers := FloatVector->New([4.1, 7.2, 1.7, 9.3, 4.4, 3.2]);
DoMedian(numbers)->PrintLine();
}... | Give a code snippet in #Objeck
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Show_the_epoch | Show the epoch | Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scenes by the implementers), b... | #Dart | Dart | main() {
print(new Date.fromEpoch(0,new TimeZone.utc()));
} | Give a code snippet in #Dart
Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the sc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #Rust | Rust | use std::collections::HashSet;
use std::fs::File;
use std::io::{self, BufRead};
use std::iter::FromIterator;
fn semordnilap(filename: &str) -> std::io::Result<()> {
let file = File::open(filename)?;
let mut seen = HashSet::new();
let mut count = 0;
for line in io::BufReader::new(file).lines() {
... | Give a code snippet in #Rust
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Fix_code_tags | Rosetta Code/Fix code tags | Task
Fix Rosetta Code deprecated code tags, with these rules:
Change <%s> to <lang %s>
Change </%s> to </lang>
Change <code %s> to <lang %s>
Change </code> to </lang>
Usage
./convert.py < wikisource.txt > converted.txt
| #Raku | Raku | my @langs = <
abap actionscript actionscript3 ada apache applescript apt_sources
asm asp autoit avisynth bash basic4gl bf blitzbasic bnf boo c caddcl
cadlisp cfdg cfm cil c_mac cobol cpp cpp-qt csharp css d delphi
diff _div dos dot eiffel email fortran freebasic genero gettext
glsl gml gnuplot groov... | Give a code snippet in #Raku
Task
Fix Rosetta Code deprecated code tags, with these rules:
Change <%s> to <lang %s>
Change </%s> to </lang>
Change <code %s> to <lang %s>
Change </code> to </lang>
Usage
./convert.py < wikisource.txt > converted.txt
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Runge-Kutta_method | Runge-Kutta method | Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equation has an exact solution:
... | #Ring | Ring |
decimals(8)
y = 1.0
for i = 0 to 100
t = i / 10
if t = floor(t)
actual = (pow((pow(t,2) + 4),2)) / 16
see "y(" + t + ") = " + y + " error = " + (actual - y) + nl ok
k1 = t * sqrt(y)
k2 = (t + 0.05) * sqrt(y + 0.05 * k1)
k3 = (t + 0.05) * sqrt(y + 0.05 * k2)
k4 = (t + 0.10) * ... | Give a code snippet in #Ring
Given the example Differential equation:
y
′
(
t
)
=
t
×
y
(
t
)
{\displaystyle y'(t)=t\times {\sqrt {y(t)}}}
With initial condition:
t
0
=
0
{\displaystyle t_{0}=0}
and
y
0
=
y
(
t
0
)
=
y
(
0
)
=
1
{\displaystyle y_{0}=y(t_{0})=y(0)=1}
This equ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #ooRexx | ooRexx | if arg~isa(.string) & arg~left(1) == "*" then call processArg arg | Give a code snippet in #ooRexx
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_a_system_command | Execute a system command | Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| #Io | Io | System runCommand("ls") stdout println | Give a code snippet in #Io
Task
Run either the ls system command (dir on Windows), or the pause system command.
Related task
Get system command output
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix-exponentiation_operator | Matrix-exponentiation operator | Most programming languages have a built-in implementation of exponentiation for integers and reals only.
Task
Demonstrate how to implement matrix exponentiation as an operator.
| #BBC_BASIC | BBC BASIC | DIM matrix(1,1), output(1,1)
matrix() = 3, 2, 2, 1
FOR power% = 0 TO 9
PROCmatrixpower(matrix(), output(), power%)
PRINT "matrix()^" ; power% " = "
FOR row% = 0 TO DIM(output(), 1)
FOR col% = 0 TO DIM(output(), 2)
PRINT output(row%,col%);
NEXT
... | Give a code snippet in #BBC_BASIC
Most programming languages have a built-in implementation of exponentiation for integers and reals only.
Task
Demonstrate how to implement matrix exponentiation as an operator.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Polynomial_regression | Polynomial regression | Find an approximating polynomial of known degree for a given data.
Example:
For input data:
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
y = {1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321};
The approximating polynomial is:
3 x2 + 2 x + 1
Here, the polynomial's coefficients are (3, 2, 1).
This task is i... | #ALGOL_68 | ALGOL 68 | MODE FIELD = REAL;
MODE
VEC = [0]FIELD,
MAT = [0,0]FIELD;
PROC VOID raise index error := VOID: (
print(("stop", new line));
stop
);
COMMENT from http://rosettacode.org/wiki/Matrix_Transpose#ALGOL_68 END COMMENT
OP ZIP = ([,]FIELD in)[,]FIELD:(
[2 LWB in:2 UPB in,1 LWB in:1UPB in]FIELD out;
FOR i FROM ... | Give a code snippet in #ALGOL_68
Find an approximating polynomial of known degree for a given data.
Example:
For input data:
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
y = {1, 6, 17, 34, 57, 86, 121, 162, 209, 262, 321};
The approximating polynomial is:
3 x2 + 2 x + 1
Here, the polynomial's coefficie... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Floyd-Warshall_algorithm | Floyd-Warshall algorithm | The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel ... | #Wren | Wren | import "/fmt" for Fmt
class FloydWarshall {
static doCalcs(weights, nVertices) {
var dist = List.filled(nVertices, null)
for (i in 0...nVertices) dist[i] = List.filled(nVertices, 1/0)
for (w in weights) dist[w[0] - 1][w[1] - 1] = w[2]
var next = List.filled(nVertices, null)
... | Give a code snippet in #Wren
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already bee... | 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... | #Phix | Phix | string s1 = "at" ?s1
string s2 = "c"&s1 ?s2
string s3 = "s"&s1 ?s3
string s4 = "m"&s1 ?s4
string s5 = "The "&s2&" "&s3&" on the "&s4&"." ?s5
| Give a code snippet in #Phix
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 lite... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Array_length | Array length | Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter frequency
Jewels and stones
I befo... | #Euphoria | Euphoria |
sequence s = {"apple","orange",2.95} -- Euphoria doesn't care what you put in a sequence
? length(s)
3 -- three objects
? length(s[1])
5 -- apple has 5 characters
? length(s[1][$])
1 -- 'e' is an atomic value
? length(s[$])
1 -- 2.95 is an atomic value
| Give a code snippet in #Euphoria
Task
Determine the amount of elements in an array.
As an example use an array holding the strings 'apple' and 'orange'.
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
Word frequency
Letter fr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #Ruby | Ruby | size = File.size('input.txt')
size = File.size('/input.txt') | Give a code snippet in #Ruby
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Greyscale_bars/Display | Greyscale bars/Display | The task is to display a series of vertical greyscale bars (contrast bars) with a sufficient number of bars to span the entire width of the display.
For the top quarter of the display, the left hand bar should be black, and we then incrementally step through six shades of grey until we have a white bar on the right ha... | #Wren | Wren | import "graphics" for Canvas, Color
import "dome" for Window
import "math" for Math
class GreyBars {
construct new(width, height) {
Window.title = "Grey bars example"
Window.resize(width, height)
Canvas.resize(width, height)
_w = width
_h = height
}
init() {
... | Give a code snippet in #Wren
The task is to display a series of vertical greyscale bars (contrast bars) with a sufficient number of bars to span the entire width of the display.
For the top quarter of the display, the left hand bar should be black, and we then incrementally step through six shades of grey until we ha... | 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... | #Babel | Babel | 'abcdefg' str2ar
{%d nl <<} eachar | Give a code snippet in #Babel
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).
Conv... | christopher/rosetta-code | |
http://rosettacode.org/wiki/RIPEMD-160 | RIPEMD-160 | RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Cod... | #Objeck | Objeck |
class Hash {
function : Main(args : String[]) ~ Nil {
in := "Rosetta Code"->ToByteArray();
hash := Encryption.Hash->RIPEMD160(in);
hash->ToHexString()->PrintLine();
}
}
| Give a code snippet in #Objeck
RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the A... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variable_size/Set | Variable size/Set | Task
Demonstrate how to specify the minimum size of a variable or a data type.
| #Pascal | Pascal | type
correctInteger = integer attribute (size = 42); | Give a code snippet in #Pascal
Task
Demonstrate how to specify the minimum size of a variable or a data type.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Operator_precedence | Operator precedence |
This page uses content from Wikipedia. The original article was at Operators in C and C++. 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
Provide a list of precedence and associativity... | #Ring | Ring |
The next table present operators from higher precedence (Evaluated first) to lower precedence.
Operator
. [] () {}
- ~ :Literal [list items]
++ - -
Start:End
* / %
+ -
<< >>
&
| ^
< > <= >=
= !=
not
and or
Assignment = += -= *= /= %=>>= <<= &= ^= |=
Example:
See 3+5*4 # prints 23
| Give a code snippet in #Ring
This page uses content from Wikipedia. The original article was at Operators in C and C++. 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
Provide a list of pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nautical_bell | Nautical bell |
Task
Write a small program that emulates a nautical bell producing a ringing bell pattern at certain times throughout the day.
The bell timing should be in accordance with Greenwich Mean Time, unless locale dictates otherwise.
It is permissible for the program to daemonize, or to slave off a scheduler, and it is per... | #Wren | Wren | import "os" for Process
import "timer" for Timer
import "/date" for Date
import "/fmt" for Fmt
var watches = ["First", "Middle", "Morning", "Forenoon", "Afternoon", "Dog", "First"]
var args = Process.arguments
if (args.count == 0) {
System.print("Please enter current time in the format (24 hour clock): hh:mm:ss... | Give a code snippet in #Wren
Task
Write a small program that emulates a nautical bell producing a ringing bell pattern at certain times throughout the day.
The bell timing should be in accordance with Greenwich Mean Time, unless locale dictates otherwise.
It is permissible for the program to daemonize, or to slave ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Read_a_PPM_file | Bitmap/Read a PPM file | Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to grayscale one.
| #Erlang | Erlang |
% This module provides basic operations on ppm files:
% Read from file, create ppm in memory (from generic bitmap) and save to file.
% Writing PPM files was introduced in roseta code task 'Bitmap/Write a PPM file'
% but the same code is included here to provide whole set of operations on ppm
% needed for purposes of ... | Give a code snippet in #Erlang
Using the data storage type defined on this page for raster images, read an image from a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
Task: Use write ppm file solution and grayscale image solution with this one in order to convert a color image to grays... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jaro_similarity | Jaro similarity | The Jaro distance is a measure of edit distance between two strings; its inverse, called the Jaro similarity, is a measure of two strings' similarity: the higher the value, the more similar the strings are. The score is normalized such that 0 equates to no similarities and 1 is an exact match.
Definition
The... | #Phix | Phix | function jaro(string str1, str2)
str1 = trim(upper(str1))
str2 = trim(upper(str2))
integer len1 = length(str1),
len2 = length(str2),
match_distance = floor(max(len1,len2)/2)-1,
match_count = 0,
half_transposed = 0
if len1==0 then return len2==0 end if
... | Give a code snippet in #Phix
The Jaro distance is a measure of edit distance between two strings; its inverse, called the Jaro similarity, is a measure of two strings' similarity: the higher the value, the more similar the strings are. The score is normalized such that 0 equates to no similarities and 1 is an ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_shuffle | Perfect shuffle | A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on:
7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠ 8♠ 9♠
J♠ Q♠ K♠→7♠ J♠ 8♠ Q♠ 9♠ K♠
When you ... | #Phix | Phix | with javascript_semantics
function perfect_shuffle(sequence deck)
integer l = length(deck), mp = l/2, k = 1
sequence res = repeat(0,l)
for i=1 to mp do
res[k] = deck[i] k += 1
res[k] = deck[i+mp] k += 1
end for
return res
end function
constant testsizes = {8, 24, 52, 100... | Give a code snippet in #Phix
A perfect shuffle (or faro/weave shuffle) means splitting a deck of cards into equal halves, and perfectly interleaving them - so that you end up with the first card from the left half, followed by the first card from the right half, and so on:
7♠ 8♠ 9♠ J♠ Q♠ K♠→7♠ 8♠ 9♠
J♠ Q♠ K♠... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #S-lang | S-lang | % String literals
variable c, ch, s, b, r, v;
c = 'A';
ch = '\x{1d7bc}';
printf("Double quotes\n");
s = "this is a single line string with\t\tbackslash substitutions";
() = fputs(s, stdout);
() = fputs("\n", stdout);
s = "this is a single line string without\t\tbackslash substitutions"R;
() = fputs(s, stdout);
()... | Give a code snippet in #S-lang
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
... | 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... | #Aime | Aime | gsss(list l, integer &start, &end, &maxsum)
{
integer e, f, i, sum;
end = f = maxsum = start = sum = 0;
for (i, e in l) {
sum += e;
if (sum < 0) {
sum = 0;
f = i + 1;
} elif (maxsum < sum) {
maxsum = sum;
end = i + 1;
star... | Give a code snippet in #Aime
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 n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brownian_tree | Brownian tree | Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The initial "seed" is placed somewhere wi... | #zkl | zkl | w:=h:=400; numParticles:=20_000;
bitmap:=PPM(w+2,h+2,0); // add borders as clip regions
bitmap[w/2,h/2]=0xff|ff|ff; // plant seed
bitmap.circle(w/2,h/2,h/2,0x0f|0f|0f); // plant seeds
fcn touching(x,y,bitmap){ // is (x,y) touching another pixel?
// (x,y) isn't on the border/edge of bitmap so no edge c... | Give a code snippet in #zkl
Brownian tree
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw a Brownian Tree.
A Brownian Tree is generated as a result of an initial seed, followed by the interaction of two processes.
The initial ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mandelbrot_set | Mandelbrot set | Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| #Phix | Phix | --
-- Mandlebrot set in ascii art demo.
--
constant b=" .:,;!/>)|&IH%*#"
atom r, i, c, C, z, Z, t, k
for y=30 to 0 by -1 do
C = y*0.1-1.5
puts(1,'\n')
for x=0 to 74 do
c = x*0.04-2
z = 0
Z = 0
r = c
i = C
k = 0
... | Give a code snippet in #Phix
Mandelbrot set
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Generate and draw the Mandelbrot set.
Note that there are many algorithms to draw Mandelbrot set and there are many functions which generate it .
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_file | Create a file | In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #C | C | #include <stdio.h>
int main() {
FILE *fh = fopen("output.txt", "w");
fclose(fh);
return 0;
} | Give a code snippet in #C
In this task, the job is to create a new empty file called "output.txt" of size 0 bytes
and an empty directory called "docs". This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Chernick%27s_Carmichael_numbers | Chernick's Carmichael numbers | In 1939, Jack Chernick proved that, for n ≥ 3 and m ≥ 1:
U(n, m) = (6m + 1) * (12m + 1) * Product_{i=1..n-2} (2^i * 9m + 1)
is a Carmichael number if all the factors are primes and, for n > 4, m is a multiple of 2^(n-4).
Example
U(3, m) = (6m + 1) * (12m + 1) * (18m + 1)
U(4, m) = U(3, m) * (2^2 * 9m + 1)... | #Julia | Julia | using Primes
function trial_pretest(k::UInt64)
if ((k % 3)==0 || (k % 5)==0 || (k % 7)==0 || (k % 11)==0 ||
(k % 13)==0 || (k % 17)==0 || (k % 19)==0 || (k % 23)==0)
return (k <= 23)
end
return true
end
function gcd_pretest(k::UInt64)
if (k <= 107)
return true
en... | Give a code snippet in #Julia
In 1939, Jack Chernick proved that, for n ≥ 3 and m ≥ 1:
U(n, m) = (6m + 1) * (12m + 1) * Product_{i=1..n-2} (2^i * 9m + 1)
is a Carmichael number if all the factors are primes and, for n > 4, m is a multiple of 2^(n-4).
Example
U(3, m) = (6m + 1) * (12m + 1) * (18m + 1)
U(4... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chinese_zodiac | Chinese zodiac | Traditionally, the Chinese have counted years using two simultaneous cycles, one of length 10 (the "celestial stems") and one of length 12 (the "terrestrial branches"); the combination results in a repeating 60-year pattern. Mapping the branches to twelve traditional animal deities results in the well-known "Chinese zo... | #F.C5.8Drmul.C3.A6 | Fōrmulæ | package main
import "fmt"
var (
animalString = []string{"Rat", "Ox", "Tiger", "Rabbit", "Dragon", "Snake",
"Horse", "Goat", "Monkey", "Rooster", "Dog", "Pig"}
stemYYString = []string{"Yang", "Yin"}
elementString = []string{"Wood", "Fire", "Earth", "Metal", "Water"}
stemCh = []rune("甲... | Give a code snippet in #F.C5.8Drmul.C3.A6
Traditionally, the Chinese have counted years using two simultaneous cycles, one of length 10 (the "celestial stems") and one of length 12 (the "terrestrial branches"); the combination results in a repeating 60-year pattern. Mapping the branches to twelve traditional animal de... | christopher/rosetta-code | |
http://rosettacode.org/wiki/De_Bruijn_sequences | de Bruijn sequences | The sequences are named after the Dutch mathematician Nicolaas Govert de Bruijn.
A note on Dutch capitalization: Nicolaas' last name is de Bruijn, the de isn't normally capitalized
unless it's the first word in a sentence. Rosetta Code (more or less by default or by fiat) requires the first word in the... | #Phix | Phix | string deBruijn = ""
for n=0 to 99 do
string a = sprintf("%02d",n)
integer a1 = a[1],
a2 = a[2]
if a2>=a1 then
deBruijn &= iff(a1=a2?a1:a)
for m=n+1 to 99 do
string ms = sprintf("%02d",m)
if ms[2]>a1 then
deBruijn &= a&ms
end if... | Give a code snippet in #Phix
The sequences are named after the Dutch mathematician Nicolaas Govert de Bruijn.
A note on Dutch capitalization: Nicolaas' last name is de Bruijn, the de isn't normally capitalized
unless it's the first word in a sentence. Rosetta Code (more or less by default or by fiat) ... | 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 ... | #Elixir | Elixir | defmodule RC do
def spiral_matrix(n) do
wide = length(to_char_list(n*n-1))
fmt = String.duplicate("~#{wide}w ", n) <> "~n"
runs = Enum.flat_map(n..1, &[&1,&1]) |> tl
delta = Stream.cycle([{0,1},{1,0},{0,-1},{-1,0}])
running(Enum.zip(runs,delta),0,-1,[])
|> Enum.with_index |> Enum.sort |> Enum... | Give a code snippet in #Elixir
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 1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Comb_sort | Sorting algorithms/Comb sort | Sorting algorithms/Comb sort
You are encouraged to solve this task according to the task description, using any language you may know.
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algor... | #Ring | Ring |
aList = [3,5,1,2,7,4,8,3,6,4,1]
see combsort(aList)
func combsort t
gapd = 1.2473
gap = len(t)
swaps = 0
while gap + swaps > 1
k = 0
swaps = 0
if gap > 1 gap = floor(gap / gapd) ok
for k = 1 to len(t) - gap
if t[k] > t[k + gap]
... | Give a code snippet in #Ring
Sorting algorithms/Comb sort
You are encouraged to solve this task according to the task description, using any language you may know.
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Image_noise | Image noise | Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| #Phix | Phix | -- demo\rosetta\ImageNoise.exw
include pGUI.e
Ihandle dlg, canvas, timer
cdCanvas cddbuffer, cdcanvas
constant TITLE = "Image noise"
integer fps = 129 -- (typical value)
function redraw_cb(Ihandle /*ih*/, integer /*posx*/, integer /*posy*/)
integer {w, h} = IupGetIntInt(canvas, "DRAWSIZE")
cdCanvasAct... | Give a code snippet in #Phix
Generate a random black and white 320x240 image continuously,
showing FPS (frames per second).
A sample image
| christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #zkl | zkl | var MsgHash=Import("zklMsgHash");
MsgHash.SHA256("Rosetta code")=="764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf" | Give a code snippet in #zkl
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_cuboid | Draw a cuboid | Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is acceptable for this task.
R... | #Lua | Lua | -- needed for actual task
cube.scale = function(self, sx, sy, sz)
for i,v in ipairs(self.verts) do
v[1], v[2], v[3] = v[1]*sx, v[2]*sy, v[3]*sz
end
end
-- only needed for output
-- (to size it for screen, given a limited camera)
cube.translate = function(self, tx, ty, tz)
for i,v in ipairs(self.verts) do
... | Give a code snippet in #Lua
Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mode | Averages/Mode | Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if possible. If it is not appropriat... | #Factor | Factor | { 11 9 4 9 4 9 } mode ! 9 | Give a code snippet in #Factor
Task[edit]
Write a program to find the mode value of a collection.
The case where the collection is empty may be ignored. Care must be taken to handle the case where the mode is non-unique.
If it is not appropriate or possible to support a general collection, use a vector (array), if p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_comments_from_a_string | Strip comments from a string | Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whitespace debacle: There is s... | #C | C | #include<stdio.h>
int main()
{
char ch, str[100];
int i;
do{
printf("\nEnter the string :");
fgets(str,100,stdin);
for(i=0;str[i]!=00;i++)
{
if(str[i]=='#'||str[i]==';')
{
str[i]=00;
break;
}
}
printf("\nThe modified string is : %s",str);
printf("\nDo you want to repeat (y/n): ");
... | Give a code snippet in #C
Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
White... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multi-dimensional_array | Multi-dimensional array | For the purposes of this task, the actual memory layout or access method of this data structure is not mandated.
It is enough to:
State the number and extent of each index to the array.
Provide specific, ordered, integer indices for all dimensions of the array together with a new value to update the indexed value.
... | #Raku | Raku | # Raku supports multi dimension arrays natively. There are no arbitrary limits on the number of dimensions or maximum indices. Theoretically, you could have an infinite number of dimensions of infinite length, though in practice more than a few dozen dimensions gets unwieldy. An infinite maximum index is a fairly commo... | Give a code snippet in #Raku
For the purposes of this task, the actual memory layout or access method of this data structure is not mandated.
It is enough to:
State the number and extent of each index to the array.
Provide specific, ordered, integer indices for all dimensions of the array together with a new value... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Merging | Associative array/Merging | Task
Define two associative arrays, where one represents the following "base" data:
Key
Value
"name"
"Rocket Skates"
"price"
12.75
"color"
"yellow"
And the other represents "update" data:
Key
Value
"price"
15.25
"color"
"red"
"year"
1974
Merge these into a new associativ... | #Nim | Nim | import tables
let t1 = {"name": "Rocket Skates", "price": "12.75", "color": "yellow"}.toTable
let t2 = {"price": "15.25", "color": "red", "year": "1974"}.toTable
var t3 = t1 # Makes a copy.
for key, value in t2.pairs:
t3[key] = value
echo t3 | Give a code snippet in #Nim
Task
Define two associative arrays, where one represents the following "base" data:
Key
Value
"name"
"Rocket Skates"
"price"
12.75
"color"
"yellow"
And the other represents "update" data:
Key
Value
"price"
15.25
"color"
"red"
"year"
1974
Merg... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #NetRexx | NetRexx | /* NetRexx */
options replace format comments java crossref savelog symbols
numeric digits 210000 /*prepare for some big 'uns. */
parse arg x y . /*allow a single number or range.*/
if x == '' then do /*no input? Then assume -30-->+30*/
x = -30
y =... | Give a code snippet in #NetRexx
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unbias_a_random_generator | Unbias a random generator |
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random number generator to create a function/method/sub... | #Scala | Scala | def biased( n:Int ) = scala.util.Random.nextFloat < 1.0 / n
def unbiased( n:Int ) = { def loop : Boolean = { val a = biased(n); if( a != biased(n) ) a else loop }; loop }
for( i <- (3 until 7) ) println {
val m = 50000
var c1,c2 = 0
(0 until m) foreach { j => if( biased(i) ) c1 += 1; if( unbiased(i) ) c2... | Give a code snippet in #Scala
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random number generator ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chowla_numbers | Chowla numbers | Chowla numbers are also known as:
Chowla's function
chowla numbers
the chowla function
the chowla number
the chowla sequence
The chowla number of n is (as defined by Chowla's function):
the sum of the divisors of n excluding unity and n
where n is a positive integer
The s... | #Raku | Raku | sub comma { $^i.flip.comb(3).join(',').flip }
sub schnitzel (\Radda, \radDA = 0) {
Radda.is-prime ?? !Radda !! ?radDA ?? Radda
!! sum flat (2 .. Radda.sqrt.floor).map: -> \RAdda {
my \RADDA = Radda div RAdda;
next if RADDA * RAdda !== Radda;
RAdda !== RADDA ?? (RAdda, RADDA) !! RADDA
... | Give a code snippet in #Raku
Chowla numbers are also known as:
Chowla's function
chowla numbers
the chowla function
the chowla number
the chowla sequence
The chowla number of n is (as defined by Chowla's function):
the sum of the divisors of n excluding unity and n
where n ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Superpermutation_minimisation | Superpermutation minimisation | A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use the first two characters 'AB'... | #Raku | Raku | for 1..8 -> $len {
my $pre = my $post = my $t = '';
for ('a'..'z')[^$len].permutations -> @p {
$t = @p.join('');
$post ~= $t unless index($post, $t);
$pre = $t ~ $pre unless index($pre, $t);
}
printf "%1d: %8d %8d\n", $len, $pre.chars, $post.chars;
} | Give a code snippet in #Raku
A superpermutation of N different characters is a string consisting of an arrangement of multiple copies of those N different characters in which every permutation of those characters can be found as a substring.
For example, representing the characters as A..Z, using N=2 we choose to use... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Simple_moving_average | Averages/Simple moving average | Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a method for computing an avera... | #Wren | Wren | import "/fmt" for Fmt
var sma = Fn.new { |period|
var i = 0
var sum = 0
var storage = []
return Fn.new { |input|
if (storage.count < period) {
sum = sum + input
storage.add(input)
}
sum = sum + input - storage[i]
storage[i] = input
i = (i... | Give a code snippet in #Wren
Computing the simple moving average of a series of numbers.
Task[edit]
Create a stateful function/class/instance that takes a period and returns a routine that takes a number as argument and returns a simple moving average of its arguments so far.
Description
A simple moving average is a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Palindrome_detection | Palindrome detection | A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibly as a wrapper to the first) which ... | #Pointless | Pointless | isPalindrome(chars) =
chars == reverse(chars) | Give a code snippet in #Pointless
A palindrome is a phrase which reads the same backward and forward.
Task[edit]
Write a function or program that checks whether a given sequence of characters (or, if you prefer, bytes)
is a palindrome.
For extra credit:
Support Unicode characters.
Write a second function (possibl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delegates | Delegates | A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:Delegation pattern.
Objects ... | #Tcl | Tcl | package require TclOO
oo::class create Delegate {
method thing {} {
return "delegate impl."
}
export thing
}
oo::class create Delegator {
variable delegate
constructor args {
my delegate {*}$args
}
method delegate args {
if {[llength $args] == 0} {
i... | Give a code snippet in #Tcl
A delegate is a helper object used by another object. The delegator may send the delegate certain messages, and provide a default implementation when there is no delegate or the delegate does not respond to a message. This pattern is heavily used in Cocoa framework on Mac OS X. See also wp:... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mastermind | Mastermind | Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may be repeated in the code
The (... | #Ring | Ring |
# Project : Mastermind
colors = ["A", "B", "C", "D"]
places = list(2)
mind = list(len(colors))
rands = list(len(colors))
master = list(len(colors))
test = list(len(colors))
guesses = 7
repeat = false
nr = 0
if repeat
for n = 1 to len(colors)
while true
rnd = random(len(colors)-1) + ... | Give a code snippet in #Ring
Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hash_join | Hash join | An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash join" algorithm, and demonstrate tha... | #Clojure | Clojure |
(defn hash-join [table1 col1 table2 col2]
(let [hashed (group-by col1 table1)]
(flatten
(for [r table2]
(for [s (hashed (col2 r))]
(merge s r))))))
(def s '({:age 27 :name "Jonah"}
{:age 18 :name "Alan"}
{:age 28 :name "Glory"}
{:age 18 :name "Popeye"}
... | Give a code snippet in #Clojure
An inner join is an operation that combines two data tables into one table, based on matching column values. The simplest way of implementing this operation is the nested loop join algorithm, but a more scalable alternative is the hash join algorithm.
Task[edit]
Implement the "hash joi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Emirp_primes | Emirp primes | An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the 10,000th emirp
In each list, the numbe... | #Visual_Basic_.NET | Visual Basic .NET | Imports System.Runtime.CompilerServices
Module Module1
<Extension()>
Function ToHashSet(Of T)(source As IEnumerable(Of T)) As HashSet(Of T)
Return New HashSet(Of T)(source)
End Function
<Extension()>
Function Reverse(number As Integer) As Integer
If number < 0 Then
Re... | Give a code snippet in #Visual_Basic_.NET
An emirp (prime spelled backwards) are primes that when reversed (in their decimal representation) are a different prime.
(This rules out palindromic primes.)
Task
show the first twenty emirps
show all emirps between 7,700 and 8,000
show the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/De_Bruijn_sequences | de Bruijn sequences | The sequences are named after the Dutch mathematician Nicolaas Govert de Bruijn.
A note on Dutch capitalization: Nicolaas' last name is de Bruijn, the de isn't normally capitalized
unless it's the first word in a sentence. Rosetta Code (more or less by default or by fiat) requires the first word in the... | #Racket | Racket | #lang racket
(define (de-bruijn k n)
(define a (make-vector (* k n) 0))
(define seq '())
(define (db t p)
(cond
[(> t n) (when (= (modulo n p) 0)
(set! seq (cons (call-with-values
(thunk (vector->values a 1 (add1 p)))
... | Give a code snippet in #Racket
The sequences are named after the Dutch mathematician Nicolaas Govert de Bruijn.
A note on Dutch capitalization: Nicolaas' last name is de Bruijn, the de isn't normally capitalized
unless it's the first word in a sentence. Rosetta Code (more or less by default or by fiat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_Chess960_starting_position | Generate Chess960 starting position | Chess960 is a variant of chess created by world champion Bobby Fischer. Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints:
as in the standard chess game, all eight white pawns must be placed on the second rank.
W... | #Julia | Julia | function generateposition()
# Placeholder knights
rank = ['♘', '♘', '♘', '♘', '♘', '♘', '♘', '♘']
lrank = length(rank)
# Check if a space is available
isfree(x::Int) = rank[x] == '♘'
# Place the King
rank[indking = rand(2:lrank-1)] = '♔'
# Place rooks
rank[indrook = rand(filter... | Give a code snippet in #Julia
Chess960 is a variant of chess created by world champion Bobby Fischer. Unlike other variants of the game, Chess960 does not require a different material, but instead relies on a random initial position, with a few constraints:
as in the standard chess game, all eight white pawns must b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_strings | Binary strings | Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings according to Wikipedia) for those la... | #AWK | AWK | #!/usr/bin/awk -f
BEGIN {
# string creation
a="123\0 abc ";
b="456\x09";
c="789";
printf("abc=<%s><%s><%s>\n",a,b,c);
# string comparison
printf("(a==b) is %i\n",a==b)
# string copying
A = a;
B = b;
C = c;
printf("ABC=<%s><%s><%s>\n",A,B,C);
# check if string is empty
if (length(a)==0) {
printf... | Give a code snippet in #AWK
Many languages have powerful and useful (binary safe) string manipulation functions, while others don't, making it harder for these languages to accomplish some tasks.
This task is about creating functions to handle binary strings (strings made of arbitrary bytes, i.e. byte strings accordi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_multiples_of_3_and_5 | Sum multiples of 3 and 5 | Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| #MiniScript | MiniScript | // simple version:
sum35 = function(n)
sum = 0
for i in range(3, n-1, 3)
sum = sum + i
end for
for i in range(5, n-1, 5)
if i % 3 then sum = sum + i // (skip multiples of 3 here)
end for
return sum
end function
print sum35(1000) | Give a code snippet in #MiniScript
Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncatable_primes | Truncatable primes | A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncatable prime as the numbers 7393, 7... | #Scala | Scala | object TruncatablePrimes {
def main(args: Array[String]): Unit = {
val max = 1000000
println(
s"""|ltPrime: ${ltPrimes.takeWhile(_ <= max).last}
|rtPrime: ${rtPrimes.takeWhile(_ <= max).last}
|""".stripMargin)
}
def ltPrimes: LazyList[Int] = 2 #:: LazyList.from(3, 2).filter(i... | Give a code snippet in #Scala
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncatab... | 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.
| #Ruby | Ruby | Shoes.app(:width => 470, :height => 380) do
PI = Shoes::TWO_PI/2
strokewidth 1
def yin_yang(x, y, radius)
fill black; stroke black
arc x, y, radius, radius, -PI/2, PI/2
fill white; stroke white
arc x, y, radius, radius, PI/2, -PI/2
oval x-radius/4, y-radius/2, radius/2-1
fill black... | Give a code snippet in #Ruby
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/Universal_Turing_machine | Universal Turing machine | One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machine in it.
Task
Simulate such ... | #Pascal | Pascal | program project1;
uses
Classes, sysutils;
type
TCurrent = record
state : string;
input : char;
end;
TMovesTo = record
state : string;
output : char;
moves : char;
end;
var
ST, ET: TDateTime;
C:TCurrent;
M:TMovesTo;
Tape, Rules:TStringList;
TP:integer; //TP = Tape position
Blank... | Give a code snippet in #Pascal
One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Delete_a_file | Delete a file | Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| #REBOL | REBOL | ; Local.
delete %input.txt
delete-dir %docs/
; Root.
delete %/input.txt
delete-dir %/docs/ | Give a code snippet in #REBOL
Task
Delete a file called "input.txt" and delete a directory called "docs".
This should be done twice: once "here", i.e. in the current working directory and once in the filesystem root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Unbias_a_random_generator | Unbias a random generator |
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random number generator to create a function/method/sub... | #Julia | Julia | using Printf
randN(N) = () -> rand(1:N) == 1 ? 1 : 0
function unbiased(biased::Function)
this, that = biased(), biased()
while this == that this, that = biased(), biased() end
return this
end
@printf "%2s | %10s | %5s | %5s | %8s" "N" "bias./unb." "1s" "0s" "pct ratio"
const nrep = 10000
for N in 3:6
... | Give a code snippet in #Julia
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random number generator ... | 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... | #D | D | import std.stdio, std.string, std.range, std.algorithm;
string nth(in uint n) pure {
static immutable suffix = "th st nd rd th th th th th th".split;
return "%d'%s".format(n, (n % 100 <= 10 || n % 100 > 20) ?
suffix[n % 10] : "th");
}
void main() {
foreach (r; [iota(26), iot... | Give a code snippet in #D
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 her... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_frequency | Word frequency | Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a letter is.
Undersc... | #Clojure | Clojure | (defn count-words [file n]
(->> file
slurp
clojure.string/lower-case
(re-seq #"\w+")
frequencies
(sort-by val >)
(take n))) | Give a code snippet in #Clojure
Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_length | String length | Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme containing combining characters.
F... | #Ruby | Ruby | "J̲o̲s̲é̲".bytesize | Give a code snippet in #Ruby
Task
Find the character and byte length of a string.
This means encodings like UTF-8 need to be handled properly, as there is not necessarily a one-to-one relationship between bytes and characters.
By character, we mean an individual Unicode code point, not a user-visible grapheme conta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Run-length_encoding | Run-length encoding | Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression... | #Raku | Raku | sub encode($str) { $str.subst(/(.) $0*/, { $/.chars ~ $0 }, :g) }
sub decode($str) { $str.subst(/(\d+) (.)/, { $1 x $0 }, :g) }
my $e = encode('WWWWWWWWWWWWBWWWWWWWWWWWWBBBWWWWWWWWWWWWWWWWWWWWWWWWBWWWWWWWWWWWWWW');
say $e;
say decode($e); | Give a code snippet in #Raku
Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a funct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Filter | Filter | Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| #Nemerle | Nemerle | def original = $[1 .. 100];
def filtered = original.Filter(fun(n) {n % 2 == 0});
WriteLine($"$filtered"); | Give a code snippet in #Nemerle
Task
Select certain elements from an Array into a new Array in a generic way.
To demonstrate, select all even numbers from an Array.
As an option, give a second solution which filters destructively,
by modifying the original Array rather than creating a new Array.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Mastermind | Mastermind | Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may be repeated in the code
The (... | #Prolog | Prolog | mastermind :- mastermind(7, 4, 8, no_duplicates).
mastermind(Colours, Length, Guesses, Duplicates) :-
between(2, 20, Colours),
between(4, 10, Length),
between(7, 20, Guesses),
member(Duplicates, [allow_duplicates, no_duplicates]),
create_board(Colours, Length, Duplicates, Board),
intro(Colours, Length, Duplic... | Give a code snippet in #Prolog
Create a simple version of the board game: Mastermind.
It must be possible to:
choose the number of colors will be used in the game (2 - 20)
choose the color code length (4 - 10)
choose the maximum number of guesses the player has (7 - 20)
choose whether or not colors may... | 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... | #WebAssembly | WebAssembly | (module $lowercase
(import "wasi_unstable" "fd_write"
(func $fd_write (param i32 i32 i32 i32) (result i32))
)
(memory 1)
(export "memory" (memory 0))
(func $main (export "_start")
(local $i i32)
(i32.store (i32.const 0) (i32.const 8)) ;; offset to start of string
(i32.store (i32.cons... | Give a code snippet in #WebAssembly
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 ... | 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... | #Go | Go | package main
import "time"
import "fmt"
func main() {
t := time.Now()
fmt.Println(t) // default format
fmt.Println(t.Format("Mon Jan 2 15:04:05 2006")) // some custom format
} | Give a code snippet in #Go
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
Dat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/RIPEMD-160 | RIPEMD-160 | RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the ASCII encoded string “Rosetta Cod... | #Kotlin | Kotlin | import org.bouncycastle.crypto.digests.RIPEMD160Digest
import org.bouncycastle.util.encoders.Hex
import kotlin.text.Charsets.US_ASCII
fun RIPEMD160Digest.inOneGo(input : ByteArray) : ByteArray {
val output = ByteArray(digestSize)
update(input, 0, input.size)
doFinal(output, 0)
return output
}
fu... | Give a code snippet in #Kotlin
RIPEMD-160 is another hash function; it computes a 160-bit message digest.
There is a RIPEMD-160 home page, with test vectors and pseudocode for RIPEMD-160.
For padding the message, RIPEMD-160 acts like MD4 (RFC 1320).
Find the RIPEMD-160 message digest of a string of octets.
Use the A... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Queue/Definition | Queue/Definition |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the order of insertion.
Operation... | #Racket | Racket |
#lang racket
(define (make-queue) (mcons #f #f))
(define (push! q x)
(define new (mcons x #f))
(if (mcar q) (set-mcdr! (mcdr q) new) (set-mcar! q new))
(set-mcdr! q new))
(define (pop! q)
(define old (mcar q))
(cond [(eq? old (mcdr q)) (set-mcar! q #f) (set-mcdr! q #f)]
[else (set-mcar! q (mcdr ol... | Give a code snippet in #Racket
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Illustration of FIFO behavior
Task
Implement a FIFO queue.
Elements are added at one side and popped from the other in the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Start_from_a_main_routine | Start from a main routine |
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages may also require similar tricker... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const proc: main is func
begin
writeln("hello world");
end func; | Give a code snippet in #Seed7
Some languages (like Gambas and Visual Basic) support two startup modes. Applications written in these languages start with an open window that waits for events, and it is necessary to do some trickery to cause a main procedure to run instead. Data driven or event driven languages m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Pythagorean_means | Averages/Pythagorean means | Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(x_{1},\ldots ,x_{n})}
for this set of p... | #Icon_and_Unicon | Icon and Unicon | link numbers # for a/g/h means
procedure main()
every put(x := [], 1 to 10)
writes("x := [ "); every writes(!x," "); write("]")
write("Arithmetic mean:", a := amean!x)
write("Geometric mean:",g := gmean!x)
write("Harmonic mean:", h := hmean!x)
write(" a >= g >= h is ", if a >= g >= h then "true" else "false")
e... | Give a code snippet in #Icon_and_Unicon
Task[edit]
Compute all three of the Pythagorean means of the set of integers 1 through 10 (inclusive).
Show that
A
(
x
1
,
…
,
x
n
)
≥
G
(
x
1
,
…
,
x
n
)
≥
H
(
x
1
,
…
,
x
n
)
{\displaystyle A(x_{1},\ldots ,x_{n})\geq G(x_{1},\ldots ,x_{n})\geq H(... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cistercian_numerals | Cistercian numerals | Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself represents the number 0. Then, glyp... | #Phix | Phix | --
-- Define each digit as {up-down multiplier, left-right multiplier, char},
-- that is starting each drawing from line 1 or 7, column 3,
-- and with `/` and `\` being flipped below when necessary.
--
with javascript_semantics
constant ds = {{{0,0,'+'},{0,1,'-'},{0,2,'-'}}, -- 1
... | Give a code snippet in #Phix
Cistercian numerals were used across Europe by Cistercian monks during the Late Medieval Period as an alternative to Roman numerals. They were used to represent base 10 integers from 0 to 9999.
How they work
All Cistercian numerals begin with a vertical line segment, which by itself repre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #Smalltalk | Smalltalk | Integer extend [
fizzbuzz [
| fb |
fb := '%<Fizz|>1%<Buzz|>2' % {
self \\ 3 == 0. self \\ 5 == 0 }.
^fb isEmpty ifTrue: [ self ] ifFalse: [ fb ]
]
]
1 to: 100 do: [ :i | i fizzbuzz displayNl ] | Give a code snippet in #Smalltalk
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print Fizz... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Trigonometric_functions | Trigonometric functions | Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evaluate to the same angle (that i... | #Phix | Phix | ?sin(PI/2)
?sin(90*PI/180)
?cos(0)
?cos(0*PI/180)
?tan(PI/4)
?tan(45*PI/180)
?arcsin(1)*2
?arcsin(1)*180/PI
?arccos(0)*2
?arccos(0)*180/PI
?arctan(1)*4
?arctan(1)*180/PI
| Give a code snippet in #Phix
Task
If your language has a library or built-in functions for trigonometry, show examples of:
sine
cosine
tangent
inverses (of the above)
using the same angle in radians and degrees.
For the non-inverse functions, each radian/degree pair should use arguments that evalua... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/Input | XML/Input | Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender="M" DateOfBirth="1990-03-04" /... | #MATLAB | MATLAB | RootXML = com.mathworks.xml.XMLUtils.createDocument('Students');
docRootNode = RootXML.getDocumentElement;
thisElement = RootXML.createElement('Student');
thisElement.setAttribute('Name','April')
thisElement.setAttribute('Gender','F')
thisElement.setAttribute('DateOfBirth','1989-01-02')
docRootNode.appendChild(thisElem... | Give a code snippet in #MATLAB
Given the following XML fragment, extract the list of student names using whatever means desired. If the only viable method is to use XPath, refer the reader to the task XML and XPath.
<Students>
<Student Name="April" Gender="F" DateOfBirth="1989-01-02" />
<Student Name="Bob" Gender... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Do-while | Loops/Do-while | Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loo... | #Lasso | Lasso | local(x = 0)
while(#x % 6 > 0 || #x == 0) => {^
++#x
'\r' // for formatting
^} | Give a code snippet in #Lasso
Start with a value at 0. Loop while value mod 6 is not equal to 0.
Each time through the loop, add 1 to the value then print it.
The loop must execute at least once.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/D... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cheryl%27s_birthday | Cheryl's birthday | Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then tells Albert the month of birth, ... | #JavaScript | JavaScript | (() => {
'use strict';
// main :: IO ()
const main = () => {
const
month = fst,
day = snd;
showLog(
map(x => Array.from(x), (
// The month with only one remaining day,
// (A's month contains only one remaining day)
... | Give a code snippet in #JavaScript
Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roots_of_unity | Roots of unity | The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| #C.2B.2B | C++ | #include <complex>
#include <cmath>
#include <iostream>
double const pi = 4 * std::atan(1);
int main()
{
for (int n = 2; n <= 10; ++n)
{
std::cout << n << ": ";
for (int k = 0; k < n; ++k)
std::cout << std::polar(1, 2*pi*k/n) << " ";
std::cout << std::endl;
}
} | Give a code snippet in #C.2B.2B
The purpose of this task is to explore working with complex numbers.
Task
Given n, find the nth roots of unity.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #Klingphix | Klingphix | include ..\Utilitys.tlhy
%limit %i
1000 !limit
( 1 $limit ) sequence
( 2 $limit sqrt int ) [ !i $i get [ ( 2 $limit 1 - $i / int ) [ $i * false swap set ] for ] if ] for
( 1 $limit false ) remove
pstack
"Press ENTER to end " input | Give a code snippet in #Klingphix
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/Modular_inverse | Modular inverse | From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
{\displaystyle \exists k\in \math... | #PureBasic | PureBasic | EnableExplicit
Declare main()
Declare.i mi(a.i, b.i)
If OpenConsole("MODULAR-INVERSE")
main() : Input() : End
EndIf
Macro ModularInverse(a, b)
PrintN(~"\tMODULAR-INVERSE(" + RSet(Str(a),5) + "," +
RSet(Str(b),5)+") = " +
RSet(Str(mi(a, b)),5))
EndMacro
Procedure main()
ModularInvers... | Give a code snippet in #PureBasic
From Wikipedia:
In modular arithmetic, the modular multiplicative inverse of an integer a modulo m is an integer x such that
a
x
≡
1
(
mod
m
)
.
{\displaystyle a\,x\equiv 1{\pmod {m}}.}
Or in other words, such that:
∃
k
∈
Z
,
a
x
=
1
+
k
m
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pythagoras_tree | Pythagoras tree |
The Pythagoras tree is a fractal tree constructed from squares. It is named after Pythagoras because each triple of touching squares encloses a right triangle, in a configuration traditionally used to represent the Pythagorean theorem.
Task
Construct a Pythagoras tree of order 7 using only vectors (no rotation or ... | #C.2B.2B | C++ | #include <windows.h>
#include <string>
#include <iostream>
const int BMP_SIZE = 720, LINE_LEN = 120, BORDER = 100;
class myBitmap {
public:
myBitmap() : pen( NULL ), brush( NULL ), clr( 0 ), wid( 1 ) {}
~myBitmap() {
DeleteObject( pen ); DeleteObject( brush );
DeleteDC( hdc ); DeleteObject( ... | Give a code snippet in #C.2B.2B
The Pythagoras tree is a fractal tree constructed from squares. It is named after Pythagoras because each triple of touching squares encloses a right triangle, in a configuration traditionally used to represent the Pythagorean theorem.
Task
Construct a Pythagoras tree of order 7 us... | 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... | #Modula-2 | Modula-2 | MODULE Entropy;
FROM InOut IMPORT WriteString, WriteLn;
FROM RealInOut IMPORT WriteReal;
FROM Strings IMPORT Length;
FROM MathLib IMPORT ln;
PROCEDURE entropy(s: ARRAY OF CHAR): REAL;
VAR freq: ARRAY [0..255] OF CARDINAL;
i, length: CARDINAL;
h, f: REAL;
BEGIN
(* the entropy of the empt... | Give a code snippet in #Modula-2
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitwise_IO | Bitwise IO | The aim of this task is to write functions (or create a class if your
language is Object Oriented and you prefer) for reading and writing sequences of
bits, most significant bit first. While the output of a asciiprint "STRING" is the ASCII byte sequence
"S", "T", "R", "I", "N", "G", the output of a "print" of the bits ... | #REXX | REXX | /* REXX ****************************************************************
* 01.11.2012 Walter Pachl
***********************************************************************/
s='STRING' /* Test input */
Say 's='s
ol='' /* initialize target ... | Give a code snippet in #REXX
The aim of this task is to write functions (or create a class if your
language is Object Oriented and you prefer) for reading and writing sequences of
bits, most significant bit first. While the output of a asciiprint "STRING" is the ASCII byte sequence
"S", "T", "R", "I", "N", "G", the ou... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First_class_environments | First class environments | According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a programming language may support "... | #Wren | Wren | import "/fmt" for Fmt
var environment = Fn.new {
class E {
construct new(value, count) {
_value = value
_count = count
}
value { _value }
count { _count }
hailstone() {
Fmt.write("$4d", _value)
if (_value == 1) return
... | Give a code snippet in #Wren
According to Wikipedia, "In computing, a first-class object ... is an entity that can be constructed at run-time, passed as a parameter, returned from a subroutine, or assigned into a variable".
Often this term is used in the context of "first class functions". In an analogous way, a prog... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #VBScript | VBScript | Dim variable As datatype
Dim var1,var2,... As datatype | Give a code snippet in #VBScript
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #PARI.2FGP | PARI/GP | my $x = 0.0;
my $true_or_false = $x ? 'true' : 'false'; # false | Give a code snippet in #PARI.2FGP
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Jewels_and_stones | Jewels and stones | Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower case letters. However, in the case ... | #BASIC256 | BASIC256 |
function contar_joyas(piedras, joyas)
cont = 0
for i = 1 to length(piedras)
bc = instr(joyas, mid(piedras, i, 1), 1)
if bc <> 0 then cont += 1
next i
return cont
end function
print contar_joyas("aAAbbbb", "aA")
print contar_joyas("ZZ", "z")
print contar_joyas("ABCDEFGHIJKLMNOPQRSTUVWXYZ@abcdefghijklmnopqrst... | Give a code snippet in #BASIC256
Jewels and stones
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Create a function which takes two string parameters: 'stones' and 'jewels' and returns an integer.
Both strings can contain any number of upper or lower c... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Price_fraction | Price fraction | A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and 1.00, rescale according to ... | #F.23 | F# | let cin = [ 0.06m .. 0.05m ..1.01m ]
let cout = [0.1m; 0.18m] @ [0.26m .. 0.06m .. 0.44m] @ [0.50m .. 0.04m .. 0.98m] @ [1.m]
let priceadjuster p =
let rec bisect lo hi =
if lo < hi then
let mid = (lo+hi)/2.
let left = p < cin.[int mid]
bisect (if left then lo else mid... | Give a code snippet in #F.23
A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_if_a_point_is_within_a_triangle | Find if a point is within a triangle | Find if a point is within a triangle.
Task
Assume points are on a plane defined by (x, y) real number coordinates.
Given a point P(x, y) and a triangle formed by points A, B, and C, determine if P is within triangle ABC.
You may use any algorithm.
Bonus: explain why the algorithm you chose works.
Re... | #D | D | import std.algorithm; //.comparison for min and max
import std.stdio;
immutable EPS = 0.001;
immutable EPS_SQUARE = EPS * EPS;
double side(double x1, double y1, double x2, double y2, double x, double y) {
return (y2 - y1) * (x - x1) + (-x2 + x1) * (y - y1);
}
bool naivePointInTriangle(double x1, double y1, do... | Give a code snippet in #D
Find if a point is within a triangle.
Task
Assume points are on a plane defined by (x, y) real number coordinates.
Given a point P(x, y) and a triangle formed by points A, B, and C, determine if P is within triangle ABC.
You may use any algorithm.
Bonus: explain why the algo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jacobsthal_numbers | Jacobsthal numbers | Jacobsthal numbers are an integer sequence related to Fibonacci numbers. Similar to Fibonacci, where each term is the sum of the previous two terms, each term is the sum of the previous, plus twice the one before that. Traditionally the sequence starts with the given terms 0, 1.
J0 = 0
J1 = 1
Jn = Jn-1 + 2 ×... | #C | C | #include <stdio.h>
#include <gmp.h>
void jacobsthal(mpz_t r, unsigned long n) {
mpz_t s;
mpz_init(s);
mpz_set_ui(r, 1);
mpz_mul_2exp(r, r, n);
mpz_set_ui(s, 1);
if (n % 2) mpz_neg(s, s);
mpz_sub(r, r, s);
mpz_div_ui(r, r, 3);
}
void jacobsthal_lucas(mpz_t r, unsigned long n) {
mp... | Give a code snippet in #C
Jacobsthal numbers are an integer sequence related to Fibonacci numbers. Similar to Fibonacci, where each term is the sum of the previous two terms, each term is the sum of the previous, plus twice the one before that. Traditionally the sequence starts with the given terms 0, 1.
J0 = 0
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Downward_for | Loops/Downward for | Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop body... | #Java | Java |
for (int i = 10; i >= 0; i--) {
System.out.println(i);
}
| Give a code snippet in #Java
Task
Write a for loop which writes a countdown from 10 to 0.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increme... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Brilliant_numbers | Brilliant numbers | Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing prime factoring algorithms.
E.G.
3 × 3 (9) is a bri... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | ClearAll[PrimesDecade]
PrimesDecade[n_Integer] := Module[{bounds},
bounds = {PrimePi[10^n] + 1, PrimePi[10^(n + 1) - 1]};
Prime[Range @@ bounds]
]
ds = Union @@ Table[Union[Times @@@ Tuples[PrimesDecade[d], 2]], {d, 0, 4}];
Multicolumn[Take[ds, 100], {Automatic, 8}, Appearance -> "Horizontal"]
sel = Min /@ Ga... | Give a code snippet in #Mathematica.2FWolfram_Language
Brilliant numbers are a subset of semiprime numbers. Specifically, they are numbers that are the product of exactly two prime numbers that both have the same number of digits when expressed in base 10.
Brilliant numbers are useful in cryptography and when testing... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Damm_algorithm | Damm algorithm | The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| #Pascal | Pascal | program DammAlgorithm;
uses
sysutils;
TYPE TA = ARRAY[0..9,0..9] OF UInt8;
CONST table : TA =
((0,3,1,7,5,9,8,6,4,2),
(7,0,9,2,1,5,4,8,6,3),
(4,2,0,6,8,7,1,3,5,9),
(1,7,5,0,9,8,3,4,2,6),
(6,1,2,3,0,4,5,9,7,8),
(3,6,... | Give a code snippet in #Pascal
The Damm algorithm is a checksum algorithm which detects all single digit errors and adjacent transposition errors.
The algorithm is named after H. Michael Damm.
Task
Verify the checksum, stored as last digit of an input.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Dinesman%27s_multiple-dwelling_problem | Dinesman's multiple-dwelling problem | Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allowed. Flexibility and ease of... | #C | C | #include <stdio.h>
#include <stdlib.h>
int verbose = 0;
#define COND(a, b) int a(int *s) { return (b); }
typedef int(*condition)(int *);
/* BEGIN problem specific setup */
#define N_FLOORS 5
#define TOP (N_FLOORS - 1)
int solution[N_FLOORS] = { 0 };
int occupied[N_FLOORS] = { 0 };
enum tenants {
baker = 0,
coop... | Give a code snippet in #C
Task
Solve Dinesman's multiple dwelling problem but in a way that most naturally follows the problem statement given below.
Solutions are allowed (but not required) to parse and interpret the problem text, but should remain flexible and should state what changes to the problem text are allow... | 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.
| #Racket | Racket |
#lang racket
(require slideshow/pict)
(define (yin-yang d)
(define base
(hc-append (inset/clip (circle d) 0 0 (- (/ d 2)) 0)
(inset/clip (disk d) (- (/ d 2)) 0 0 0)))
(define with-top
(ct-superimpose
base
(cc-superimpose (colorize (disk (/ d 2)) "white")
(d... | Give a code snippet in #Racket
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/Jacobsthal_numbers | Jacobsthal numbers | Jacobsthal numbers are an integer sequence related to Fibonacci numbers. Similar to Fibonacci, where each term is the sum of the previous two terms, each term is the sum of the previous, plus twice the one before that. Traditionally the sequence starts with the given terms 0, 1.
J0 = 0
J1 = 1
Jn = Jn-1 + 2 ×... | #ALGOL_68 | ALGOL 68 | BEGIN # find some Jacobsthal and related Numbers #
INT max jacobsthal = 29; # highest Jacobsthal number we will find #
INT max oblong = 20; # highest Jacobsthal oblong number we will find #
INT max j prime = 20; # number of Jacobsthal prinmes we will find #
... | Give a code snippet in #ALGOL_68
Jacobsthal numbers are an integer sequence related to Fibonacci numbers. Similar to Fibonacci, where each term is the sum of the previous two terms, each term is the sum of the previous, plus twice the one before that. Traditionally the sequence starts with the given terms 0, 1.
J... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Xiaolin_Wu%27s_line_algorithm | Xiaolin Wu's line algorithm | Task
Implement the Xiaolin Wu's line algorithm described in Wikipedia.
This algorithm draws anti-aliased lines.
Related task
See Bresenham's line algorithm for aliased lines.
| #Racket | Racket | #lang racket
(require 2htdp/image)
(define (plot img x y c)
(define c*255 (exact-round (* (- 1 c) 255)))
(place-image
(rectangle 1 1 'solid (make-color c*255 c*255 c*255 255))
x y img))
(define ipart exact-floor) ; assume that a "round-down" is what we want when -ve
;;; `round` is built in -- but we'll us... | Give a code snippet in #Racket
Task
Implement the Xiaolin Wu's line algorithm described in Wikipedia.
This algorithm draws anti-aliased lines.
Related task
See Bresenham's line algorithm for aliased lines.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Munching_squares | Munching squares | Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| #Haskell | Haskell | import qualified Data.ByteString as BY (writeFile, pack)
import Data.Bits (xor)
main :: IO ()
main =
BY.writeFile
"out.pgm"
(BY.pack
(fmap (fromIntegral . fromEnum) "P5\n256 256\n256\n" ++
[ x `xor` y
| x <- [0 .. 255]
, y <- [0 .. 255] ])) | Give a code snippet in #Haskell
Render a graphical pattern where each pixel is colored by the value of 'x xor y' from an arbitrary color table.
| christopher/rosetta-code |
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