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 |
|---|---|---|---|---|---|
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Elena | Elena | import system'collections;
import system'routines;
import extensions;
import extensions'text;
public program()
{
var numbers := new Range(1,10).summarize(new ArrayList());
var summary := numbers.accumulate(new Variable(0), (a,b => a + b));
var product := numbers.accumulate(new Variable(1), (a,b => a *... |
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #Tailspin | Tailspin |
templates chaocipher&{left:,right:,decode:}
templates permute
def ctshift: [ $@chaocipher.ct($..last)..., $@chaocipher.ct(1..$-1)...];
def p1: $ mod 26 + 1;
def ptshift: [ $@chaocipher.pt($p1..last)..., $@chaocipher.pt(1..$p1-1)...];
..|@chaocipher: { ct: [ $ctshift(1), $ctshift(3..14)..., $ctshift(... |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Nim | Nim | const n = 15
var t = newSeq[int](n + 2)
t[1] = 1
for i in 1..n:
for j in countdown(i, 1): t[j] += t[j-1]
t[i+1] = t[i]
for j in countdown(i+1, 1): t[j] += t[j-1]
stdout.write t[i+1] - t[i], " "
stdout.write '\n' |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #OCaml | OCaml |
let catalan : int ref = ref 0 in
Printf.printf "%d ," 1 ;
for i = 2 to 9 do
let nm : int ref = ref 1 in
let den : int ref = ref 1 in
for k = 2 to i do
nm := (!nm)*(i+k);
den := (!den)*k;
catalan := (!nm)/(!den) ;
done;
print_int (!catalan); print_string "," ;
done;;
|
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Liberty_BASIC | Liberty BASIC |
dog$ = "Benjamin"
Dog$ = "Samba"
DOG$ = "Bernie"
print "The three dogs are "; dog$; ", "; Dog$; " and "; DOG$; "."
end
|
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Lua | Lua | dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
print( "There are three dogs named "..dog..", "..Dog.." and "..DOG.."." ) |
http://rosettacode.org/wiki/Cartesian_product_of_two_or_more_lists | Cartesian product of two or more lists | Task
Show one or more idiomatic ways of generating the Cartesian product of two arbitrary lists in your language.
Demonstrate that your function/method correctly returns:
{1, 2} × {3, 4} = {(1, 3), (1, 4), (2, 3), (2, 4)}
and, in contrast:
{3, 4} × {1, 2} = {(3, 1), (3, 2), (4, 1), (4, 2)}
Also demonstrate, using y... | #Fortran | Fortran |
! Created by simon on 29/04/2021.
! ifort -o cartesian_product cartesian_product.f90 -check all
module tuple
implicit none
private
public :: tuple_t, operator(*), print
type tuple_t(n)
integer, len :: n
integer, private :: v(n)
contains
procedure, public :: pri... |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #Befunge | Befunge | 0>:.:000p1>\:00g-#v_v
v 2-1*2p00 :+1g00\< $
> **00g1+/^v,*84,"="<
_^#<`*53:+1>#,.#+5< @ |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #COBOL | COBOL | *> INVOKE
INVOKE FooClass "someMethod" RETURNING bar *> Factory object
INVOKE foo-instance "anotherMethod" RETURNING bar *> Instance object
*> Inline method invocation
MOVE FooClass::"someMethod" TO bar *> Factory object
MOVE foo-instance::"anotherMethod" TO bar *> Instance object |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #CoffeeScript | CoffeeScript | class Foo
@staticMethod: -> 'Bar'
instanceMethod: -> 'Baz'
foo = new Foo
foo.instanceMethod() #=> 'Baz'
Foo.staticMethod() #=> 'Bar' |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Common_Lisp | Common Lisp | (defclass my-class ()
((x
:accessor get-x ;; getter function
:initarg :x ;; arg name
:initform 0))) ;; initial value
;; declaring a public class method
(defmethod square-x ((class-instance my-class))
(* (get-x class-instance) (get-x class-instance)))
;; create an instance of my-class
(defva... |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #C | C | #include <stdio.h>
#include <stdlib.h>
#include <dlfcn.h>
int myopenimage(const char *in)
{
static int handle=0;
fprintf(stderr, "internal openimage opens %s...\n", in);
return handle++;
}
int main()
{
void *imglib;
int (*extopenimage)(const char *);
int imghandle;
imglib = dlopen("./fakeimglib.so",... |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #BASIC256 | BASIC256 |
global ancho, alto, intervalo
ancho = 81 : alto = 5
dim intervalo(alto, ancho)
subroutine Cantor()
for i = 0 to alto - 1
for j = 0 to ancho - 1
intervalo[i, j] = "■"
next j
next i
end subroutine
subroutine ConjCantor(inicio, longitud, indice)
segmento = longitud / 3
if segmento = 0 then return
for i =... |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #BQN | BQN | Cantor ← {" •" ⊏˜ >⥊¨(¯1⊸⊏⊢¨¨⊢)1‿0‿1∧⌜⍟(↕𝕩)1} |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #Arturo | Arturo | n: new 1
d: new 1
calkinWilf: function [] .export:[n,d] [
n: (d - n) + 2 * (n/d) * d
tmp: d
d: n
n: tmp
return @[n d]
]
first20: [[1 1]] ++ map 1..19 => calkinWilf
print "The first 20 terms of the Calkwin-Wilf sequence are:"
print map first20 'f -> ~"|f\0|/|f\1|"
n: new 1
d: new 1
indx: new 1
... |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #BQN | BQN | GCD ← {m 𝕊⍟(0<m←𝕨|𝕩) 𝕨}
_while_ ← {𝔽⍟𝔾∘𝔽_𝕣_𝔾∘𝔽⍟𝔾𝕩}
Sim ← { # Simplify a fraction
x𝕊1: 𝕨‿1;
0𝕊y: 0‿𝕩;
⌊𝕨‿𝕩 ÷ 𝕨 GCD 𝕩
}
Add ← { # Add two fractions
0‿b 𝕊 𝕩: 𝕩;
𝕨 𝕊 0‿y: 𝕨;
a‿b 𝕊 x‿y:
((a×y)+x×b) Sim b×y
}
Next ← {n‿d: ⌽(2×⌊÷´n‿d)‿1 Add (d-n)‿d} # Next term
Cal ← {Next⍟𝕩 1‿1}
•S... |
http://rosettacode.org/wiki/Canny_edge_detector | Canny edge detector | Task
Write a program that performs so-called canny edge detection on an image.
A possible algorithm consists of the following steps:
Noise reduction. May be performed by Gaussian filter.
Compute intensity gradient (matrices
G
x
{\displaystyle G_{x}}
and
G
y
{\displaystyle G_{y}}
) ... | #Perl | Perl | # 20220120 Perl programming solution
use strict;
use warnings;
use lib '/home/hkdtam/lib';
use Image::EdgeDetect;
my $detector = Image::EdgeDetect->new();
$detector->process('./input.jpg', './output.jpg') or die; # na.cx/i/pHYdUrV.jpg |
http://rosettacode.org/wiki/Canny_edge_detector | Canny edge detector | Task
Write a program that performs so-called canny edge detection on an image.
A possible algorithm consists of the following steps:
Noise reduction. May be performed by Gaussian filter.
Compute intensity gradient (matrices
G
x
{\displaystyle G_{x}}
and
G
y
{\displaystyle G_{y}}
) ... | #PHP | PHP |
// input: r,g,b in range 0..255
function RGBtoHSV($r, $g, $b) {
$r = $r/255.; // convert to range 0..1
$g = $g/255.;
$b = $b/255.;
$cols = array("r" => $r, "g" => $g, "b" => $b);
asort($cols, SORT_NUMERIC);
$min = key(array_slice($cols, 1)); // "r", "g" or "b"
$max = key(array_slice($cols, -1)); // "r", "g" or... |
http://rosettacode.org/wiki/Canonicalize_CIDR | Canonicalize CIDR | Task
Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form.
That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address.
Example
Given ... | #JavaScript | JavaScript | const canonicalize = s => {
// Prepare a DataView over a 16 Byte Array buffer.
// Initialised to all zeros.
const dv = new DataView(new ArrayBuffer(16));
// Get the ip-address and cidr components
const [ip, cidr] = s.split('/');
// Make sure the cidr component is a usable int, and
// d... |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #Java | Java | import java.util.*;
import java.util.stream.IntStream;
public class CastingOutNines {
public static void main(String[] args) {
System.out.println(castOut(16, 1, 255));
System.out.println(castOut(10, 1, 99));
System.out.println(castOut(17, 1, 288));
}
static List<Integer> castOu... |
http://rosettacode.org/wiki/Catmull%E2%80%93Clark_subdivision_surface | Catmull–Clark subdivision surface | Implement the Catmull-Clark surface subdivision (description on Wikipedia), which is an algorithm that maps from a surface (described as a set of points and a set of polygons with vertices at those points) to another more refined surface. The resulting surface will always consist of a mesh of quadrilaterals.
The proce... | #Wren | Wren | import "/dynamic" for Tuple, Struct
import "/sort" for Sort
import "/math" for Int
import "/fmt" for Fmt
var Point = Tuple.create("Point", ["x", "y", "z"])
var fields = [
"pn1", // point number 1
"pn2", // point number 2
"fn1", // face number 1
"fn2", // face number 2
"cp" // center point
]... |
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes | Carmichael 3 strong pseudoprimes | A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it.
The Miller Rabin Test uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this.
The purpose of this task is to investigate such numbers using a met... | #FreeBASIC | FreeBASIC | ' version 17-10-2016
' compile with: fbc -s console
' using a sieve for finding primes
#Define max_sieve 10000000 ' 10^7
ReDim Shared As Byte isprime(max_sieve)
' translated the pseudo code to FreeBASIC
Sub carmichael3(p1 As Integer)
If isprime(p1) = 0 Then Exit Sub
Dim As Integer h3, d, p2, p3, t1, t2
... |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Elixir | Elixir | iex(1)> Enum.reduce(1..10, fn i,acc -> i+acc end)
55
iex(2)> Enum.reduce(1..10, fn i,acc -> i*acc end)
3628800
iex(3)> Enum.reduce(10..-10, "", fn i,acc -> acc <> to_string(i) end)
"109876543210-1-2-3-4-5-6-7-8-9-10" |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Erlang | Erlang |
-module(catamorphism).
-export([test/0]).
test() ->
Nums = lists:seq(1,10),
Summation =
lists:foldl(fun(X, Acc) -> X + Acc end, 0, Nums),
Product =
lists:foldl(fun(X, Acc) -> X * Acc end, 1, Nums),
Concatenation =
lists:foldr(
fun(X, Acc) -> integer_to_list(X) ++ Acc end,
"",
Nums),
{Summ... |
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
ReadOnly L_ALPHABET As String = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
ReadOnly R_ALPHABET As String = "PTLNBQDEOYSFAVZKGJRIHWXUMC"
Enum Mode
ENCRYPT
DECRYPT
End Enum
Function Exec(text As String, mode As Mode, Optional showSteps As Boolean = False) As String
Dim l... |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Oforth | Oforth | import: mapping
: pascal( n -- [] )
[ 1 ] n #[ dup [ 0 ] + [ 0 ] rot + zipWith( #+ ) ] times ;
: catalan( n -- m )
n 2 * pascal at( n 1+ ) n 1+ / ; |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #PARI.2FGP | PARI/GP | vector(15,n,binomial(2*n,n)-binomial(2*n,n+1)) |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #M2000_Interpreter | M2000 Interpreter |
MoDuLe CheckIT {
\\ keys as case sensitive if they are strings
Inventory A= "Dog":=1, "dog":=2,"DOG":="Hello", 100:="Dog"
Print A("Dog"), A("dog"), A$("DOG"), A$(100)
\\ Enumeration get type as defined (same case)
Enum Dogs {Benjamin, Samba, Bernie}
Print Type$(Bernie)="Dogs"
... |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Maple | Maple | > dog, Dog, DOG := "Benjamin", "Samba", "Bernie":
> if nops( { dog, Dog, DOG } ) = 3 then
> printf( "There are three dogs named %s, %s and %s.\n", dog, Dog, DOG )
> elif nops( { dog, Dog, DOG } ) = 2 then
> printf( "WTF? There are two dogs named %s and %s.\n", op( { dog, Dog, DOG } ) )
> else
> printf( "There is ... |
http://rosettacode.org/wiki/Cartesian_product_of_two_or_more_lists | Cartesian product of two or more lists | Task
Show one or more idiomatic ways of generating the Cartesian product of two arbitrary lists in your language.
Demonstrate that your function/method correctly returns:
{1, 2} × {3, 4} = {(1, 3), (1, 4), (2, 3), (2, 4)}
and, in contrast:
{3, 4} × {1, 2} = {(3, 1), (3, 2), (4, 1), (4, 2)}
Also demonstrate, using y... | #Go | Go | package main
import "fmt"
type pair [2]int
func cart2(a, b []int) []pair {
p := make([]pair, len(a)*len(b))
i := 0
for _, a := range a {
for _, b := range b {
p[i] = pair{a, b}
i++
}
}
return p
}
func main() {
fmt.Println(cart2([]int{1, 2}, []int{3... |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #Bracmat | Bracmat | ( out$straight
& ( C
=
. ( F
= i prod
. !arg:0&1
| 1:?prod
& 0:?i
& whl
' ( 1+!i:~>!arg:?i
& !i*!prod:?prod
)
& !prod
)
& F$(2*!arg)*(F$(!arg+1)*F$!arg)^-1
)
& -... |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #D | D | struct Cat {
static int staticMethod() {
return 2;
}
string dynamicMethod() { // Never virtual.
return "Mew!";
}
}
class Dog {
static int staticMethod() {
return 5;
}
string dynamicMethod() { // Virtual method.
return "Woof!";
}
}
void main() {
... |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Dragon | Dragon | r = new run()
r.val() |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #C.23 | C# | using System.Runtime.InteropServices;
class Program {
[DllImport("fakelib.dll")]
public static extern int fakefunction(int args);
static void Main(string[] args) {
int r = fakefunction(10);
}
} |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #COBOL | COBOL | identification division.
program-id. callsym.
data division.
working-storage section.
01 handle usage pointer.
01 addr usage program-pointer.
procedure division.
call "dlopen" using
by reference null
by value 1
returning hand... |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #11l | 11l | F no_args() {}
// call
no_args()
F fixed_args(x, y)
print(‘x=#., y=#.’.format(x, y))
// call
fixed_args(1, 2) // x=1, y=2
// named arguments
fixed_args(x' 1, y' 2)
F opt_args(x = 1)
print(x)
// calls
opt_args() // 1
opt_args(3.141) // 3.141 |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #C | C | #include <stdio.h>
#define WIDTH 81
#define HEIGHT 5
char lines[HEIGHT][WIDTH];
void init() {
int i, j;
for (i = 0; i < HEIGHT; ++i) {
for (j = 0; j < WIDTH; ++j) lines[i][j] = '*';
}
}
void cantor(int start, int len, int index) {
int i, j, seg = len / 3;
if (seg == 0) return;
fo... |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #Bracmat | Bracmat | ( 1:?a
& 0:?i
& whl
' ( 1+!i:<20:?i
& (2*div$(!a,1)+1+-1*!a)^-1:?a
& out$!a
)
& ( r2cf
= floor
. div$(!arg,1):?floor
& ( !floor:!arg
| !floor r2cf$((!arg+-1*!floor)^-1)
)
)
& ( get-term-num
= ans dig pwr
. (0,1,1):(?ans,?dig,?pwr)
& r2cf$!arg:?n
& ... |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #C.2B.2B | C++ | #include <iostream>
#include <vector>
#include <boost/rational.hpp>
using rational = boost::rational<unsigned long>;
unsigned long floor(const rational& r) {
return r.numerator()/r.denominator();
}
rational calkin_wilf_next(const rational& term) {
return 1UL/(2UL * floor(term) + 1UL - term);
}
std::vect... |
http://rosettacode.org/wiki/Canny_edge_detector | Canny edge detector | Task
Write a program that performs so-called canny edge detection on an image.
A possible algorithm consists of the following steps:
Noise reduction. May be performed by Gaussian filter.
Compute intensity gradient (matrices
G
x
{\displaystyle G_{x}}
and
G
y
{\displaystyle G_{y}}
) ... | #Phix | Phix | --
-- demo\rosetta\Canny_Edge_Detection.exw
-- =====================================
--
without js -- imImage, im_width, im_height, im_pixel, IupImageRGB,
-- imFileImageLoadBitmap, and IupImageFromImImage()
include pGUI.e
constant TITLE = "Canny Edge Detection",
IMGFILE = "Valve.png",
C_E... |
http://rosettacode.org/wiki/Canonicalize_CIDR | Canonicalize CIDR | Task
Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form.
That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address.
Example
Given ... | #Julia | Julia | using Sockets
function canonCIDR(cidr::String)
cidr = replace(cidr, r"\.(\.|\/)" => s".0\1") # handle ..
cidr = replace(cidr, r"\.(\.|\/)" => s".0\1") # handle ...
ip = split(cidr, "/")
dig = length(ip) > 1 ? 2^(32 - parse(UInt8, ip[2])) : 1
ip4 = IPv4(UInt64(IPv4(ip[1])) & (0xffffffff - dig + 1))... |
http://rosettacode.org/wiki/Canonicalize_CIDR | Canonicalize CIDR | Task
Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form.
That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address.
Example
Given ... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | ClearAll[CanonicalizeCIDR]
CanonicalizeCIDR[str_String] := Module[{i, ip, chop, keep, change},
If[StringMatchQ[str, "*.*.*.*/*"],
i = StringSplit[str, "." | "/"];
i = Interpreter["Integer"] /@ i;
If[MatchQ[i, {_Integer, _Integer, _Integer, _Integer, _Integer}],
If[AllTrue[i, Between[{0, 255}]],
{ip,... |
http://rosettacode.org/wiki/Canonicalize_CIDR | Canonicalize CIDR | Task
Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form.
That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address.
Example
Given ... | #Nim | Nim | import net
import strutils
proc canonicalize*(address: var IpAddress; nbits: Positive) =
## Canonicalize an IP address.
var zbits = 32 - nbits # Number of bits to reset.
# We process byte by byte which avoids byte order issues.
for idx in countdown(address.address_v4.high, address.address_v4.low):
... |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #JavaScript | JavaScript | function main(s, e, bs, pbs) {
bs = bs || 10;
pbs = pbs || 10
document.write('start:', toString(s), ' end:', toString(e),
' base:', bs, ' printBase:', pbs)
document.write('<br>castOutNine: ');
castOutNine()
document.write('<br>kaprekar: ');
kaprekar()
document.write('<br><br>')
... |
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes | Carmichael 3 strong pseudoprimes | A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it.
The Miller Rabin Test uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this.
The purpose of this task is to investigate such numbers using a met... | #Go | Go | package main
import "fmt"
// Use this rather than % for negative integers
func mod(n, m int) int {
return ((n % m) + m) % m
}
func isPrime(n int) bool {
if n < 2 { return false }
if n % 2 == 0 { return n == 2 }
if n % 3 == 0 { return n == 3 }
d := 5
for d * d <= n {
if n % d == 0 {... |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Excel | Excel | FOLDROW
=LAMBDA(op,
LAMBDA(a,
LAMBDA(xs,
LET(
b, op(a)(HEADROW(xs)),
IF(1 < COLUMNS(xs),
FOLDROW(op)(b)(
TAILROW(xs)
),
b
)
)
)
)
)
up... |
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #Vlang | Vlang | type Mode = int
const(
encrypt = Mode(0)
decrypt = Mode(1)
)
const(
l_alphabet = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
r_alphabet = "PTLNBQDEOYSFAVZKGJRIHWXUMC"
)
fn chao(text string, mode Mode, show_steps bool) string {
len := text.len
if text.bytes().len != len {
println("Text contains non-... |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Pascal | Pascal |
Program CatalanNumbers
type
tElement = Uint64;
var
Catalan : array[0..50] of tElement;
procedure GetCatalan(L:longint);
var
PasTri : array[0..100] of tElement;
j,k: longInt;
begin
l := l*2;
PasTri[0] := 1;
j := 0;
while (j<L) do
begin
inc(j);
k := (j+1) div 2;
PasTri[k] :=PasTri[k-1];... |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | dog = "Benjamin"; Dog = "Samba"; DOG = "Bernie";
"The three dogs are named "<> dog <>", "<> Dog <>" and "<> DOG
-> "The three dogs are named Benjamin, Samba and Bernie" |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #MATLAB_.2F_Octave | MATLAB / Octave | dog = 'Benjamin';
Dog = 'Samba';
DOG = 'Bernie';
printf('There are three dogs %s, %s, %s.\n',dog, Dog, DOG); |
http://rosettacode.org/wiki/Cartesian_product_of_two_or_more_lists | Cartesian product of two or more lists | Task
Show one or more idiomatic ways of generating the Cartesian product of two arbitrary lists in your language.
Demonstrate that your function/method correctly returns:
{1, 2} × {3, 4} = {(1, 3), (1, 4), (2, 3), (2, 4)}
and, in contrast:
{3, 4} × {1, 2} = {(3, 1), (3, 2), (4, 1), (4, 2)}
Also demonstrate, using y... | #Groovy | Groovy | class CartesianCategory {
static Iterable multiply(Iterable a, Iterable b) {
assert [a,b].every { it != null }
def (m,n) = [a.size(),b.size()]
(0..<(m*n)).inject([]) { prod, i -> prod << [a[i.intdiv(n)], b[i%n]].flatten() }
}
} |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #Brat | Brat | catalan = { n |
true? n == 0
{ 1 }
{ (2 * ( 2 * n - 1) / ( n + 1 )) * catalan(n - 1) }
}
0.to 15 { n |
p "#{n} - #{catalan n}"
} |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Dyalect | Dyalect | //Static method on a built-in type Integer
static func Integer.Div(x, y) {
x / y
}
//Instance method
func Integer.Div(n) {
this / n
}
print(Integer.Div(12, 3))
print(12.Div(3)) |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #E | E | someObject.someMethod(someParameter) |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Elena | Elena |
console.printLine("Hello"," ","World!");
|
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #Common_Lisp | Common Lisp | CL-USER> (cffi:load-foreign-library "libX11.so")
#<CFFI::FOREIGN-LIBRARY {1004F4ECC1}>
CL-USER> (cffi:foreign-funcall "XOpenDisplay"
:string #+sbcl (sb-posix:getenv "DISPLAY")
#-sbcl ":0.0"
:pointer)
#.(SB-SYS:INT-SAP #... |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #Crystal | Crystal | libm = LibC.dlopen("libm.so.6", LibC::RTLD_LAZY)
sqrtptr = LibC.dlsym(libm, "sqrt") unless libm.null?
if sqrtptr
sqrtproc = Proc(Float64, Float64).new sqrtptr, Pointer(Void).null
at_exit { LibC.dlclose(libm) }
else
sqrtproc = ->Math.sqrt(Float64)
end
puts "the sqrt of 4 is #{sqrtproc.call(4.0)}" |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #360_Assembly | 360 Assembly | X DS F
Y DS F
Z DS F |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #C.23 | C# | using System;
namespace CantorSet {
class Program {
const int WIDTH = 81;
const int HEIGHT = 5;
private static char[,] lines = new char[HEIGHT, WIDTH];
static Program() {
for (int i = 0; i < HEIGHT; i++) {
for (int j = 0; j < WIDTH; j++) {
... |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #EDSAC_order_code | EDSAC order code |
[For Rosetta Code. EDSAC program, Initial Orders 2.
Prints the first 20 terms of the Calkin-Wilf sequence.
Uses term{n} to calculate term{n + 1}.]
[Print subroutine for non-negative 17-bit integers.
Parameters: 0F = integer to be printed (not preserved)
1F = character for leading zero (preserved)
W... |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #F.23 | F# |
// Calkin Wilf Sequence. Nigel Galloway: January 9th., 2021
let cW=Seq.unfold(fun(n)->Some(n,seq{for n,g in n do yield (n,n+g); yield (n+g,g)}))(seq[(1,1)])|>Seq.concat
|
http://rosettacode.org/wiki/Canny_edge_detector | Canny edge detector | Task
Write a program that performs so-called canny edge detection on an image.
A possible algorithm consists of the following steps:
Noise reduction. May be performed by Gaussian filter.
Compute intensity gradient (matrices
G
x
{\displaystyle G_{x}}
and
G
y
{\displaystyle G_{y}}
) ... | #Python | Python | #!/bin/python
import numpy as np
from scipy.ndimage.filters import convolve, gaussian_filter
from scipy.misc import imread, imshow
def CannyEdgeDetector(im, blur = 1, highThreshold = 91, lowThreshold = 31):
im = np.array(im, dtype=float) #Convert to float to prevent clipping values
#Gaussian blur to reduce noise
... |
http://rosettacode.org/wiki/Canonicalize_CIDR | Canonicalize CIDR | Task
Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form.
That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address.
Example
Given ... | #Perl | Perl | #!/usr/bin/env perl
use v5.16;
use Socket qw(inet_aton inet_ntoa);
# canonicalize a CIDR block: make sure none of the host bits are set
if (!@ARGV) {
chomp(@ARGV = <>);
}
for (@ARGV) {
# dotted-decimal / bits in network part
my ($dotted, $size) = split m#/#;
# get IP as binary string
my $binary = spr... |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #jq | jq | def co9:
def digits: tostring | explode | map(. - 48); # "0" is 48
if . == 9 then 0
elif 0 <= . and . <= 8 then .
else digits | add | co9
end; |
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes | Carmichael 3 strong pseudoprimes | A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it.
The Miller Rabin Test uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this.
The purpose of this task is to investigate such numbers using a met... | #Haskell | Haskell | #!/usr/bin/runhaskell
import Data.Numbers.Primes
import Control.Monad (guard)
carmichaels = do
p <- takeWhile (<= 61) primes
h3 <- [2..(p-1)]
let g = h3 + p
d <- [1..(g-1)]
guard $ (g * (p - 1)) `mod` d == 0 && (-1 * p * p) `mod` h3 == d `mod` h3
let q = 1 + (((p - 1) * g) `div` d)
guard $ isPrime q
... |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #F.23 | F# | > let nums = [1 .. 10];;
val nums : int list = [1; 2; 3; 4; 5; 6; 7; 8; 9; 10]
> let summation = List.fold (+) 0 nums;;
val summation : int = 55
> let product = List.fold (*) 1 nums;;
val product : int = 3628800
> let concatenation = List.foldBack (fun x y -> x + y) (List.map (fun i -> i.ToString()) nums) "";;
v... |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Factor | Factor | { 1 2 4 6 10 } 0 [ + ] reduce . |
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #Wren | Wren | class Chao {
static encrypt { 0 }
static decrypt { 1 }
static exec(text, mode, showSteps) {
var len = text.count
if (len != text.bytes.count) Fiber.abort("Text contains non-ASCII characters.")
var left = "HXUCZVAMDSLKPEFJRIGTWOBNYQ"
var right = "PTLNBQDEOYSFAVZKGJRIHWXUMC"... |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Perl | Perl | use constant N => 15;
my @t = (0, 1);
for(my $i = 1; $i <= N; $i++) {
for(my $j = $i; $j > 1; $j--) { $t[$j] += $t[$j-1] }
$t[$i+1] = $t[$i];
for(my $j = $i+1; $j>1; $j--) { $t[$j] += $t[$j-1] }
print $t[$i+1] - $t[$i], " ";
} |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Maxima | Maxima | /* Maxima is case sensitive */
a: 1$
A: 2$
is(a = A);
false |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #min | min | "Benjamin" :dog
"Samba" :Dog
"Bernie" :DOG
"There are three dogs named $1, $2, and $3." (dog Dog DOG)=> % print |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #MiniScript | MiniScript | dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
print "There are three dogs named " + dog + ", " + Dog + " and " + DOG |
http://rosettacode.org/wiki/Cartesian_product_of_two_or_more_lists | Cartesian product of two or more lists | Task
Show one or more idiomatic ways of generating the Cartesian product of two arbitrary lists in your language.
Demonstrate that your function/method correctly returns:
{1, 2} × {3, 4} = {(1, 3), (1, 4), (2, 3), (2, 4)}
and, in contrast:
{3, 4} × {1, 2} = {(3, 1), (3, 2), (4, 1), (4, 2)}
Also demonstrate, using y... | #Haskell | Haskell | cartProd :: [a] -> [b] -> [(a, b)]
cartProd xs ys =
[ (x, y)
| x <- xs
, y <- ys ] |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #BQN | BQN | Cat←{ 0⊸<◶⟨1, (𝕊-⟜1)×(¯2+4×⊢)÷1+⊢⟩ 𝕩 }
Fact ← ×´1+↕
Cat1 ← { # direct formula
⌊0.5 + (Fact 2×𝕩) ÷ (Fact 𝕩+1) × Fact 𝕩
}
Cat2 ← { # header based recursion
0: 1;
(𝕊 𝕩-1)×2×(1-˜2×𝕩)÷𝕩+1
}
Cat¨ ↕15
Cat1¨ ↕15
Cat2¨ ↕15 |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Elixir | Elixir |
defmodule ObjectCall do
def new() do
spawn_link(fn -> loop end)
end
defp loop do
receive do
{:concat, {caller, [str1, str2]}} ->
result = str1 <> str2
send caller, {:ok, result}
loop
end
end
def concat(obj, str1, str2) do
send obj, {:concat, {self(), [str1, ... |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Factor | Factor | USING: accessors io kernel literals math sequences ;
IN: rosetta-code.call-a-method
! Define some classes.
SINGLETON: dog
TUPLE: cat sassiness ;
! Define a constructor for cat.
C: <cat> cat
! Define a generic word that dispatches on the object at the top
! of the data stack.
GENERIC: speak ( obj -- )
! Define m... |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #D | D | pragma(lib, "user32.lib");
import std.stdio, std.c.windows.windows;
extern(Windows) UINT GetDoubleClickTime();
void main() {
writeln(GetDoubleClickTime());
} |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #Dart | Dart |
int add(int num1, int num2) {
return num1 + num2;
}
|
http://rosettacode.org/wiki/Call_a_foreign-language_function | Call a foreign-language function | Task
Show how a foreign language function can be called from the language.
As an example, consider calling functions defined in the C language. Create a string containing "Hello World!" of the string type typical to the language. Pass the string content to C's strdup. The content can be copied if necessary. Get the... | #8th | 8th |
\ tell 8th what the function expects:
"ZZ" "strdup" func: strdup
"VZ" "free" func: free
\ call the external funcs
"abc" dup \ now we have two strings "abc" on the stack
strdup .s cr \ after strdup, you'll have the new (but duplicate) string on the stack
\ the ".s" will show both strings and you can see they are... |
http://rosettacode.org/wiki/Call_a_function | Call a function | Task
Demonstrate the different syntax and semantics provided for calling a function.
This may include:
Calling a function that requires no arguments
Calling a function with a fixed number of arguments
Calling a function with optional arguments
Calling a function with a variable number of arguments
C... | #6502_Assembly | 6502 Assembly | JSR myFunction |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #C.2B.2B | C++ | #include <iostream>
const int WIDTH = 81;
const int HEIGHT = 5;
char lines[WIDTH*HEIGHT];
void cantor(int start, int len, int index) {
int seg = len / 3;
if (seg == 0) return;
for (int i = index; i < HEIGHT; i++) {
for (int j = start + seg; j < start + seg * 2; j++) {
int pos = i * WIDTH + j;
lines[pos... |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #Factor | Factor | USING: formatting io kernel lists lists.lazy math
math.continued-fractions math.functions math.parser prettyprint
sequences strings vectors ;
: next-cw ( x -- y ) [ floor dup + ] [ 1 swap - + recip ] bi ;
: calkin-wilf ( -- list ) 1 [ next-cw ] lfrom-by ;
: >continued-fraction ( x -- seq )
1vector [ dup last ... |
http://rosettacode.org/wiki/Calkin-Wilf_sequence | Calkin-Wilf sequence | The Calkin-Wilf sequence contains every nonnegative rational number exactly once.
It can be calculated recursively as follows:
a1 = 1
an+1 = 1/(2⌊an⌋+1-an) for n > 1
Task part 1
Show on this page terms 1 through 20 of the Calkin-Wilf sequence.
To avoid floating point error, you may want to ... | #Forth | Forth | \ Calkin-Wilf sequence
: frac. swap . ." / " . ;
: cw-next ( num den -- num den ) 2dup / over * 2* over + rot - ;
: cw-seq ( n -- )
1 1 rot
0 do
cr 2dup frac. cw-next
loop 2drop ;
variable index
variable bit-state
variable bit-position
: r2cf-next ( num1 den1 -- num2 den2 u ) swap over >r s>d r> sm/rem... |
http://rosettacode.org/wiki/Canny_edge_detector | Canny edge detector | Task
Write a program that performs so-called canny edge detection on an image.
A possible algorithm consists of the following steps:
Noise reduction. May be performed by Gaussian filter.
Compute intensity gradient (matrices
G
x
{\displaystyle G_{x}}
and
G
y
{\displaystyle G_{y}}
) ... | #Raku | Raku | #include <stdio.h>
#include <string.h>
#include <magick/MagickCore.h>
int CannyEdgeDetector(
const char *infile, const char *outfile,
double radius, double sigma, double lower, double upper ) {
ExceptionInfo *exception;
Image *image, *processed_image, *output;
ImageInfo *input_info;... |
http://rosettacode.org/wiki/Canonicalize_CIDR | Canonicalize CIDR | Task
Implement a function or program that, given a range of IPv4 addresses in CIDR notation (dotted-decimal/network-bits), will return/output the same range in canonical form.
That is, the IP address portion of the output CIDR block must not contain any set (1) bits in the host part of the address.
Example
Given ... | #Phix | Phix | with javascript_semantics -- (not likely useful)
function canonicalize_cidr(string cidr)
cidr = substitute(cidr,"."," ") -- (else %d eats 0.0 etc)
if not find('/',cidr) then cidr &= "/32" end if
sequence res = scanf(cidr,"%d %d %d %d/%d")
if length(res)=1 then
integer {a,b,c,d,m} = res[1]
... |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #Julia | Julia | co9(x) = x == 9 ? 0 :
1<=x<=8 ? x :
co9(sum(digits(x))) |
http://rosettacode.org/wiki/Casting_out_nines | Casting out nines | Task (in three parts)
Part 1
Write a procedure (say
c
o
9
(
x
)
{\displaystyle {\mathit {co9}}(x)}
) which implements Casting Out Nines as described by returning the checksum for
x
{\displaystyle x}
. Demonstrate the procedure using the examples given there, or others you may consider lucky.
Par... | #Kotlin | Kotlin | // version 1.1.3
fun castOut(base: Int, start: Int, end: Int): List<Int> {
val b = base - 1
val ran = (0 until b).filter { it % b == (it * it) % b }
var x = start / b
val result = mutableListOf<Int>()
while (true) {
for (n in ran) {
val k = b * x + n
if (k < start) ... |
http://rosettacode.org/wiki/Carmichael_3_strong_pseudoprimes | Carmichael 3 strong pseudoprimes | A lot of composite numbers can be separated from primes by Fermat's Little Theorem, but there are some that completely confound it.
The Miller Rabin Test uses a combination of Fermat's Little Theorem and Chinese Division Theorem to overcome this.
The purpose of this task is to investigate such numbers using a met... | #Icon_and_Unicon | Icon and Unicon | link "factors"
procedure main(A)
n := integer(!A) | 61
every write(carmichael3(!n))
end
procedure carmichael3(p1)
every (isprime(p1), (h := 1+!(p1-1)), (d := !(h+p1-1))) do
if (mod(((h+p1)*(p1-1)),d) = 0, mod((-p1*p1),h) = mod(d,h)) then {
p2 := 1 + (p1-1)*(h+p1)/d
p3 := ... |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Forth | Forth | : lowercase? ( c -- f )
[char] a [ char z 1+ ] literal within ;
: char-upcase ( c -- C )
dup lowercase? if bl xor then ; |
http://rosettacode.org/wiki/Catamorphism | Catamorphism | Reduce is a function or method that is used to take the values in an array or a list and apply a function to successive members of the list to produce (or reduce them to), a single value.
Task
Show how reduce (or foldl or foldr etc), work (or would be implemented) in your language.
See also
Wikipedia article: ... | #Fortran | Fortran | SUBROUTINE FOLD(t,F,i,ist,lst)
INTEGER t
BYNAME F
DO i = ist,lst
t = F
END DO
END SUBROUTINE FOLD !Result in temp.
temp = a(1); CALL FOLD(temp,temp*a(i),i,2,N) |
http://rosettacode.org/wiki/Chaocipher | Chaocipher | Description
The Chaocipher was invented by J.F.Byrne in 1918 and, although simple by modern cryptographic standards, does not appear to have been broken until the algorithm was finally disclosed by his family in 2010.
The algorithm is described in this paper by M.Rubin in 2010 and there is a C# implementation here.
... | #zkl | zkl | class Chao{
var [const private] lAlphabet = "HXUCZVAMDSLKPEFJRIGTWOBNYQ",
rAlphabet = "PTLNBQDEOYSFAVZKGJRIHWXUMC";
fcn encode(text){ code(text,encodeL); }
fcn decode(text){ code(text,decodeL); }
// reset alphabets each [en|de]code and maintain re-entrancy
fcn code(text,f){ text.apply(f,Data(Voi... |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #Phix | Phix | constant N = 15 -- accurate to 30, nan/inf for anything over 514 (gmp version is below).
sequence catalan = {}, -- (>=1 only)
p = repeat(1,N+1)
atom p1
for i=1 to N do
p1 = p[1]*2
catalan = append(catalan,p1-p[2])
for j=1 to N-i+1 do
p1 += p[j+1]
p[j] = p1
end for
-- ?p[1.... |
http://rosettacode.org/wiki/Catalan_numbers/Pascal%27s_triangle | Catalan numbers/Pascal's triangle | Task
Print out the first 15 Catalan numbers by extracting them from Pascal's triangle.
See
Catalan Numbers and the Pascal Triangle. This method enables calculation of Catalan Numbers using only addition and subtraction.
Catalan's Triangle for a Number Triangle that generates Catalan Numbers using onl... | #PicoLisp | PicoLisp | (de bino (N K)
(let f
'((N)
(if (=0 N) 1 (apply * (range 1 N))) )
(/
(f N)
(* (f (- N K)) (f K)) ) ) )
(for N 15
(println
(-
(bino (* 2 N) N)
(bino (* 2 N) (inc N)) ) ) )
(bye) |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Modula-2 | Modula-2 | MODULE dog;
IMPORT InOut;
TYPE String = ARRAY [0..31] OF CHAR;
VAR dog, Dog, DOG : String;
(* No compiler error, so the rest is simple *)
BEGIN
InOut.WriteString ("Three happy dogs.");
InOut.WriteLn
END dog. |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Nanoquery | Nanoquery | dog = "Benjamin"
Dog = "Samba"
DOG = "Bernie"
print format("The three dogs are named %s, %s, and %s.\n", dog, Dog, DOG) |
http://rosettacode.org/wiki/Case-sensitivity_of_identifiers | Case-sensitivity of identifiers | Three dogs (Are there three dogs or one dog?) is a code snippet used to illustrate the lettercase sensitivity of the programming language. For a case-sensitive language, the identifiers dog, Dog and DOG are all different and we should get the output:
The three dogs are named Benjamin, Samba and Bernie.
For a language... | #Nemerle | Nemerle | def dog = "Benjamin";
def Dog = "Samba";
def DOG = "Bernie";
WriteLine($"The three dogs are named $dog, $Dog, and $DOG"); |
http://rosettacode.org/wiki/Cartesian_product_of_two_or_more_lists | Cartesian product of two or more lists | Task
Show one or more idiomatic ways of generating the Cartesian product of two arbitrary lists in your language.
Demonstrate that your function/method correctly returns:
{1, 2} × {3, 4} = {(1, 3), (1, 4), (2, 3), (2, 4)}
and, in contrast:
{3, 4} × {1, 2} = {(3, 1), (3, 2), (4, 1), (4, 2)}
Also demonstrate, using y... | #J | J | { 1776 1789 ; 7 12 ; 4 14 23 ; 0 1 NB. result is 4 dimensional array with shape 2 2 3 2
┌────────────┬────────────┐
│1776 7 4 0 │1776 7 4 1 │
├────────────┼────────────┤
│1776 7 14 0 │1776 7 14 1 │
├────────────┼────────────┤
│1776 7 23 0 │1776 7 23 1 │
└────────────┴────────────┘
┌────────────┬────────────┐
│... |
http://rosettacode.org/wiki/Catalan_numbers | Catalan numbers | Catalan numbers
You are encouraged to solve this task according to the task description, using any language you may know.
Catalan numbers are a sequence of numbers which can be defined directly:
C
n
=
1
n
+
1
(
2
n
n
)
=
(
2
n
)
!
(
n
+
1
)
!
n
!
for
n
≥
0.
{\displaystyle C... | #C | C | #include <stdio.h>
typedef unsigned long long ull;
ull binomial(ull m, ull n)
{
ull r = 1, d = m - n;
if (d > n) { n = d; d = m - n; }
while (m > n) {
r *= m--;
while (d > 1 && ! (r%d) ) r /= d--;
}
return r;
}
ull catalan1(int n) {
return binomial(2 * n, n) / (1 + n);
}
ull catalan2(int n) {
int... |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Forth | Forth | include lib/compare.4th
include 4pp/lib/foos.4pp
[ASSERT] \ enable assertions
:: Cat
class
method: dynamicCat \ virtual method
end-class {
:static staticCat { 2 } ; \ static method
:method { s" Mew!" } ; defines dynamicCat
} ... |
http://rosettacode.org/wiki/Call_an_object_method | Call an object method | In object-oriented programming a method is a function associated with a particular class or object. In most forms of object oriented implementations methods can be static, associated with the class itself; or instance, associated with an instance of a class.
Show how to call a static or class method, and an instance m... | #Fortran | Fortran |
! type declaration
type my_type
contains
procedure, pass :: method1
procedure, pass, pointer :: method2
end type my_type
! declare object of type my_type
type(my_type) :: mytype_object
!static call
call mytype_object%method1() ! call method1 defined as subroutine
!instance?
mytype_object%method2() ! call metho... |
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