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/Magic_squares_of_odd_order | Magic squares of odd order | A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The numbers are usually (but not always) t... | #ERRE | ERRE |
PROGRAM MAGIC_SQUARE
!$INTEGER
PROCEDURE Magicsq(size,filename$)
LOCAL DIM sq[25,25] ! array to hold square
IF (size AND 1)=0 OR size<3 THEN
PRINT PRINT(CHR$(7)) ! beep
PRINT("error: size is not odd or size is smaller then 3")
PAUSE(3)
EXIT PROCEDURE
END IF
! filename$ <> "" then save ma... | Give a code snippet in #ERRE
A magic square is an NxN square matrix whose numbers (usually integers) consist of consecutive numbers arranged so that the sum of each row and column, and both long (main) diagonals are equal to the same sum (which is called the magic number or magic constant).
The numbers ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Apply_a_callback_to_an_array | Apply a callback to an array | Task
Take a combined set of elements and apply a function to each element.
| #D.C3.A9j.C3.A0_Vu | Déjà Vu | !. map @++ [ 1 4 8 ]
#implemented roughly like this:
#map f lst:
# ]
# for i in lst:
# f i
# [ | Give a code snippet in #D.C3.A9j.C3.A0_Vu
Task
Take a combined set of elements and apply a function to each element.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Rare_numbers | Rare numbers | Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must be positive
the sum and the ... | #FreeBASIC | FreeBASIC | Function revn(n As ULongInt, nd As ULongInt) As ULongInt
Dim As ULongInt r
For i As UInteger = 1 To nd
r = r * 10 + n Mod 10
n = n \ 10
Next i
Return r
End Function
Dim As UInteger nd = 2, count, lim = 90, n = 20
Do
n += 1
Dim As ULongInt r = revn(n,nd)
If r < n Then
... | Give a code snippet in #FreeBASIC
Definitions and restrictions
Rare numbers are positive integers n where:
n is expressed in base ten
r is the reverse of n (decimal digits)
n must be non-palindromic (n ≠ r)
(n+r) is the sum
(n-r) is the difference and must b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Magic_8-ball | Magic 8-ball | Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
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 before E except after C
Bioinformatics/base count
Count occurren... | #Liberty_BASIC | Liberty BASIC | data "It is certain","It is decidedly so","Without a doubt","Yes - definitely",_
"You may rely on it","As I see it, yes","Most likely","Outlook good","Yes",_
"Signs point to yes","Reply hazy, try again","Ask again later","Better not tell you now",_
"Cannot predict now","Concentrate and ask again","Don't count on it","M... | Give a code snippet in #Liberty_BASIC
Task
Create Magic 8-Ball.
See details at: Magic 8-Ball.
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 before E except after C
Bi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Penney%27s_game | Penney's game | Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Heads, or HTH for short.
The other pla... | #Lua | Lua |
function penny_game()
local player, computer = "", ""
function player_choose()
io.write( "Enter your sequence of three H and/or T: " )
local t = io.read():upper()
if #t > 3 then t = t:sub( 1, 3 )
elseif #t < 3 then return ""
end
for i = 1, 3 do
c =... | Give a code snippet in #Lua
Penney's game is a game where two players bet on being the first to see a particular sequence of heads or tails in consecutive tosses of a fair coin.
It is common to agree on a sequence length of three then one player will openly choose a sequence, for example:
Heads, Tails, Heads, or ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #PostScript | PostScript |
% over keys and values
<</a 1 /b 2 /c 3>> {= =} forall
% just keys
<</a 1 /b 2 /c 3>> {= } forall
% just values
<</a 1 /b 2 /c 3>> {pop =} forall
| Give a code snippet in #PostScript
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Higher-order_functions | Higher-order functions | Task
Pass a function as an argument to another function.
Related task
First-class functions
| #Go | Go | package main
import "fmt"
func func1(f func(string) string) string { return f("a string") }
func func2(s string) string { return "func2 called with " + s }
func main() { fmt.Println(func1(func2)) } | Give a code snippet in #Go
Task
Pass a function as an argument to another function.
Related task
First-class functions
| 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
| #Common_Lisp | Common Lisp | (with-output-to-string (stream) (extensions:run-program "ls" nil :output stream)) | Give a code snippet in #Common_Lisp
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/Middle_three_digits | Middle three digits | Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be tested with the following values;... | #C.2B.2B | C++ | #include <iostream>
std::string middleThreeDigits(int n)
{
auto number = std::to_string(std::abs(n));
auto length = number.size();
if (length < 3) {
return "less than three digits";
} else if (length % 2 == 0) {
return "even number of digits";
} else {
return number.subst... | Give a code snippet in #C.2B.2B
Task
Write a function/procedure/subroutine that is called with an integer value and returns the middle three digits of the integer if possible or a clear indication of an error if this is not possible.
Note: The order of the middle digits should be preserved.
Your function should be ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_variables | Special variables | Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| #PARI.2FGP | PARI/GP | use English; # enables use of long variable names
$. $INPUT_LINE_NUMBER # sequence number
$, $OUTPUT_FIELD_SEPARATOR # output field separator
$; $SUBSCRIPT_SEPARATOR # subscript separator for multidimensional array emulation
$_ $ARG # topic/current... | Give a code snippet in #PARI.2FGP
Special variables have a predefined meaning within a computer programming language.
Task
List the special variables used within the language.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Write_to_Windows_event_log | Write to Windows event log | Task
Write script status to the Windows Event Log
| #D | D | import std.process;
import std.stdio;
void main() {
auto cmd = executeShell(`EventCreate /t INFORMATION /id 123 /l APPLICATION /so Dlang /d "Rosetta Code Example"`);
if (cmd.status == 0) {
writeln("Output: ", cmd.output);
} else {
writeln("Failed to execute command, status=", cmd.status)... | Give a code snippet in #D
Task
Write script status to the Windows Event Log
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Feigenbaum_constant_calculation | Feigenbaum constant calculation | Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| #C.23 | C# | using System;
namespace FeigenbaumConstant {
class Program {
static void Main(string[] args) {
var maxIt = 13;
var maxItJ = 10;
var a1 = 1.0;
var a2 = 0.0;
var d1 = 3.2;
Console.WriteLine(" i d");
for (int i = 2; i <... | Give a code snippet in #C.23
Task
Calculate the Feigenbaum constant.
See
Details in the Wikipedia article: Feigenbaum constant.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Flow-control_structures | Flow-control structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Struc... | #Visual_Basic_.NET | Visual Basic .NET | Sub bar2()
Dim x = 0
GoTo label
x = 5
label:
Console.WriteLine(x)
End Sub | Give a code snippet in #Visual_Basic_.NET
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Haversine_formula | Haversine formula |
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equation important in navigation, g... | #Go | Go | package main
import (
"fmt"
"math"
)
func haversine(θ float64) float64 {
return .5 * (1 - math.Cos(θ))
}
type pos struct {
φ float64 // latitude, radians
ψ float64 // longitude, radians
}
func degPos(lat, lon float64) pos {
return pos{lat * math.Pi / 180, lon * math.Pi / 180}
}
const r... | Give a code snippet in #Go
This page uses content from Wikipedia. The original article was at Haversine formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The haversine formula is an equatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dutch_national_flag_problem | Dutch national flag problem |
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the colours in the Dutch national fla... | #AppleScript | AppleScript | use AppleScript version "2.3.1" -- OS X 10.9 (Mavericks) or later — for these 'use' commands!
-- This script uses a customisable AppleScript sort available at <https://macscripter.net/viewtopic.php?pid=194430#p194430>.
-- It's assumed that scripters will know how and where to install it as a library.
use sorter : scrip... | Give a code snippet in #AppleScript
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Sather | Sather | class MAIN is
main is
x ::= #VEC(|1.0, 3.0, -5.0|);
y ::= #VEC(|4.0, -2.0, -1.0|);
#OUT + x.dot(y) + "\n";
end;
end; | Give a code snippet in #Sather
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -... | 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... | #FreeBASIC | FreeBASIC | ' FB 1.05. 0 Win64
Dim i As Integer = 0
Do
i += 1
Print i; " ";
Loop While i Mod 6 <> 0
Print
Sleep | Give a code snippet in #FreeBASIC
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
Loo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #GAP | GAP | Walk := function(name, op)
local dir, file, e;
dir := Directory(name);
for e in SortedList(DirectoryContents(name)) do
file := Filename(dir, e);
if IsDirectoryPath(file) then
if not (e in [".", ".."]) then
Walk(file, op);
fi;
else
op(file);
fi;
od;
end;
# This will print filenames
Walk(".", D... | Give a code snippet in #GAP
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pascal%27s_triangle | Pascal's triangle | Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is either 1 or the sum of the two elemen... | #X86_Assembly | X86 Assembly |
%include "io.inc"
section .text
global CMAIN
CMAIN:
mov ebx, 7 ;size
call mloop
ret
mloop:
mov edx, 0 ;edx stands for the nth line
looping:
push ebx
push edx
call line
pop edx
pop ebx
inc edx
cmp edx, ebx
jl looping
xor eax, eax
ret
line:
mov ecx, 0 ;ecx stands for the nth character in each line
... | Give a code snippet in #X86_Assembly
Pascal's triangle is an arithmetic and geometric figure often associated with the name of Blaise Pascal, but also studied centuries earlier in India, Persia, China and elsewhere.
Its first few rows look like this:
1
1 1
1 2 1
1 3 3 1
where each element of each row is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Largest_proper_divisor_of_n | Largest proper divisor of n | Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
with Ada.Integer_Text_IO; use Ada.Integer_Text_IO;
procedure Main is
subtype param_type is Integer range 1 .. 100;
function lpd (n : in param_type) return param_type is
result : param_type := 1;
begin
for divisor in reverse 1 .. n / 2 loop
if n ... | Give a code snippet in #Ada
Task
a(1) = 1; for n > 1, a(n) = largest proper divisor of n, where n < 101 .
| 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.
| #Dyalect | Dyalect | func Array.Filter(pred) {
var arr = []
for x in this when pred(x) {
arr.Add(x)
}
arr
}
var arr = [1..20].Filter(x => x % 2 == 0)
print(arr) | Give a code snippet in #Dyalect
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/Substitution_cipher | Substitution cipher | Substitution Cipher Implementation - File Encryption/Decryption
Task
Encrypt a input/source file by replacing every upper/lower case alphabets of the source file with another predetermined upper/lower case alphabets or symbols and save it into another output/encrypted file and then again convert that output/encrypt... | #IS-BASIC | IS-BASIC | 100 PROGRAM "SuChiper.bas"
110 STRING ST$(1 TO 2)*52,K$*1
120 LET ST$(1)="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
130 LET ST$(2)="VsciBjedgrzyHalvXZKtUPumGfIwJxqOCFRApnDhQWobLkESYMTN"
140 CLEAR SCREEN:PRINT "1 - encode, 2 - decode"
150 DO
160 LET K$=INKEY$
170 LOOP UNTIL K$="1" OR K$="2"
180 IF K$="1" T... | Give a code snippet in #IS-BASIC
Substitution Cipher Implementation - File Encryption/Decryption
Task
Encrypt a input/source file by replacing every upper/lower case alphabets of the source file with another predetermined upper/lower case alphabets or symbols and save it into another output/encrypted file and then... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_an_object_at_a_given_address | Create an object at a given address |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Applesoft_BASIC | Applesoft BASIC | 0 DEF FN P(A) = PEEK (A) + PEEK (A + 1) * 256
100 :
110 REM CREATE AN INTEGER OBJECT
120 :
130 I$ = CHR$ (42)
140 POKE 236, PEEK (131)
150 POKE 237, PEEK (132)
160 PRINT "HERE IS AN INTEGER : " ASC (I$)
200 :
210 REM PRINT THE MACHINE ADDRESS OF THE OBJECT
220 :
230 PRINT "ITS ADDRESS IS ... | Give a code snippet in #Applesoft_BASIC
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String O... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Last_letter-first_letter | Last letter-first letter | A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the category, they fall out of the ga... | #11l | 11l | F order_words(words)
DefaultDict[Char, Set[String]] byfirst
L(word) words
byfirst[word[0]].add(word)
R byfirst
F linkfirst(&byfirst; sofar)
assert(!sofar.empty)
V chmatch = sofar.last.last
V options = byfirst[chmatch] - Set(sofar)
I options.empty
R sofar
E
V alternatives = ... | Give a code snippet in #11l
A certain children's game involves starting with a word in a particular category. Each participant in turn says a word, but that word must begin with the final letter of the previous word. Once a word has been given, it cannot be repeated. If an opponent cannot give a word in the cate... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Modular_exponentiation | Modular exponentiation | Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
235139930337346448646612254452369009474497523... | #Sidef | Sidef | say expmod(
2988348162058574136915891421498819466320163312926952423791023078876139,
2351399303373464486466122544523690094744975233415544072992656881240319,
10**40) | Give a code snippet in #Sidef
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
23513993033734... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hailstone_sequence | Hailstone sequence | The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1
The (unproven) Collatz conje... | #Elena | Elena | import system'collections;
import extensions;
const int maxNumber = 100000;
Hailstone(int n,Map<int,int> lengths)
{
if (n == 1)
{
^ 1
};
while (true)
{
if (lengths.containsKey(n))
{
^ lengths[n]
}
else
{
if (n.isEven())
... | Give a code snippet in #Elena
The Hailstone sequence of numbers can be generated from a starting positive integer, n by:
If n is 1 then the sequence ends.
If n is even then the next n of the sequence = n/2
If n is odd then the next n of the sequence = (3 * n) + 1 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jacobi_symbol | Jacobi symbol | The Jacobi symbol is a multiplicative function that generalizes the Legendre symbol. Specifically, the Jacobi symbol (a | n) equals the product of the Legendre symbols (a | p_i)^(k_i), where n = p_1^(k_1)*p_2^(k_2)*...*p_i^(k_i) and the Legendre symbol (a | p) denotes the value of a ^ ((p-1)/2) (mod p)
(a | p) ≡ 1 ... | #Sidef | Sidef | func jacobi(n, k) {
assert(k > 0, "#{k} must be positive")
assert(k.is_odd, "#{k} must be odd")
var t = 1
while (n %= k) {
var v = n.valuation(2)
t *= (-1)**v if (k%8 ~~ [3,5])
n >>= v
(n,k) = (k,n)
t = -t if ([n%4, k%4] == [3,3])
}
k==1 ? t : 0
}... | Give a code snippet in #Sidef
The Jacobi symbol is a multiplicative function that generalizes the Legendre symbol. Specifically, the Jacobi symbol (a | n) equals the product of the Legendre symbols (a | p_i)^(k_i), where n = p_1^(k_1)*p_2^(k_2)*...*p_i^(k_i) and the Legendre symbol (a | p) denotes the value of a ^ ((p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Longest_increasing_subsequence | Longest increasing subsequence | Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15\}}
Note that a list may have m... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | LongestAscendingSequence/@{{3,2,6,4,5,1},{0,8,4,12,2,10,6,14,1,9,5,13,3,11,7,15}} | Give a code snippet in #Mathematica.2FWolfram_Language
Calculate and show here a longest increasing subsequence of the list:
{
3
,
2
,
6
,
4
,
5
,
1
}
{\displaystyle \{3,2,6,4,5,1\}}
And of the list:
{
0
,
8
,
4
,
12
,
2
,
10
,
6
,
14
,
1
,
9
,
5
,
13
,
3
,
11
,
7
,
15
}
{\displaystyle \{0,8,4,12,2,10,... | 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 ... | #6502_Assembly | 6502 Assembly | LDA #0
STA $F0 ; LOWER NUMBER
LDA #1
STA $F1 ; HIGHER NUMBER
LDX #0
LOOP: LDA $F1
STA $0F1B,X
STA $F2 ; OLD HIGHER NUMBER
ADC $F0
STA $F1 ; NEW HIGHER NUMBER
LDA $F2
STA $F0 ; NEW LOWER NUMBER
INX
... | Give a code snippet in #6502_Assembly
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 solut... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Quaternion_type | Quaternion type | Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number might be -3 + 2i,
wher... | #Prolog | Prolog | % A quaternion is represented as a complex term qx/4
add(qx(R0,I0,J0,K0), qx(R1,I1,J1,K1), qx(R,I,J,K)) :-
!, R is R0+R1, I is I0+I1, J is J0+J1, K is K0+K1.
add(qx(R0,I,J,K), F, qx(R,I,J,K)) :-
number(F), !, R is R0 + F.
add(F, qx(R0,I,J,K), Qx) :-
add(qx(R0,I,J,K), F, Qx).
mul(qx(R0,I0,J0,K0), qx(R1,I1,J1,K1), qx(... | Give a code snippet in #Prolog
Quaternions are an extension of the idea of complex numbers.
A complex number has a real and complex part, sometimes written as a + bi,
where a and b stand for real numbers, and i stands for the square root of minus 1.
An example of a complex number... | 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... | #Sidef | Sidef | func forprimes(a, b, callback) {
for (var p = a.dec.next_prime; p <= b; p.next_prime!) {
callback(p)
}
}
func is_emirp(p) {
var str = Str(p)
var rev = str.reverse
(str != rev) && is_prime(Num(rev))
}
func emirp_list(count) {
var i = 13
var inc = (100 + 10*count)
var n = []
... | Give a code snippet in #Sidef
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/User_input/Text | User input/Text | User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| #BBC_BASIC | BBC BASIC | INPUT LINE "Enter a string: " string$
INPUT "Enter a number: " number
PRINT "String = """ string$ """"
PRINT "Number = " ; number | Give a code snippet in #BBC_BASIC
User input/Text is part of Short Circuit's Console Program Basics selection.
Task
Input a string and the integer 75000 from the text console.
See also: User input/Graphical
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_limit_of_recursion | Find limit of recursion | Find limit of recursion is part of Short Circuit's Console Program Basics selection.
Task
Find the limit of recursion.
| #Common_Lisp | Common Lisp |
(defun recurse () (recurse))
(trace recurse)
(recurse)
| Give a code snippet in #Common_Lisp
Find limit of recursion is part of Short Circuit's Console Program Basics selection.
Task
Find the limit of recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #Oforth | Oforth | String method: isPalindrome self reverse self == ; | Give a code snippet in #Oforth
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 a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Tokenize_a_string_with_escaping | Tokenize a string with escaping | Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules for splitting:
The fields that were s... | #Arturo | Arturo | tokenize: function [s sep esc][
escaping: 0
loop 0..(size s)-1 [i][
chr: get split s i
if? escaping=1 [
prints chr
escaping: 0
]
else [
case [chr]
when? [=sep] [print ""]
when? [=esc] [escaping: 1]
else [prints chr]
]
]
print ""
]
str: "one^|uno||three^^^^|four^^^|^cuatro|"
tok... | Give a code snippet in #Arturo
Task[edit]
Write a function or program that can split a string at each non-escaped occurrence of a separator character.
It should accept three input parameters:
The string
The separator character
The escape character
It should output a list of strings.
Details
Rules for spl... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Selection_sort | Sorting algorithms/Selection sort |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Erlang | Erlang |
-module(solution).
-import(lists,[delete/2,max/1]).
-compile(export_all).
selection_sort([],Sort)-> Sort;
selection_sort(Ar,Sort)->
M=max(Ar),
Ad=delete(M,Ar),
selection_sort(Ad,[M|Sort]).
print_array([])->ok;
print_array([H|T])->
io:format("~p~n",[H]),
print_array(T).
main()->
Ans=selection_sort([1,5,7,8,4,... | Give a code snippet in #Erlang
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #newLISP | newLISP | (define (dot-product x y)
(apply + (map * x y)))
(println (dot-product '(1 3 -5) '(4 -2 -1))) | Give a code snippet in #newLISP
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #PARI.2FGP | PARI/GP |
efrac(f)=my(v=List());while(f,my(x=numerator(f),y=denominator(f));listput(v,ceil(y/x));f=(-y)%x/y/v[#v]);Vec(v);
show(f)=my(n=f\1,v=efrac(f-n)); print1(f" = ["n"; "v[1]); for(i=2,#v,print1(", "v[i])); print("]");
best(n)=my(denom,denomAt,term,termAt,v); for(a=1,n-1,for(b=a+1,n, v=efrac(a/b); if(#v>term, termAt=a/b; t... | Give a code snippet in #PARI.2FGP
An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1... | 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, ... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | opts = Tuples[{{"May"}, {15, 16, 19}}]~Join~Tuples[{{"June"}, {17, 18}}]~Join~Tuples[{{"July"}, {14, 16}}]~Join~Tuples[{{"August"}, {14, 15, 17}}];
monthsdelete = Select[GatherBy[opts, Last], Length /* EqualTo[1]][[All, 1, 1]];
opts = DeleteCases[opts, {Alternatives @@ monthsdelete, _}]
removedates = Catenate@Select[Ga... | Give a code snippet in #Mathematica_.2F_Wolfram_Language
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, Au... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Babbage_problem | Babbage problem |
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill, Electronic Computers, second edition, 1970, p.... | #Microsoft_Small_Basic | Microsoft Small Basic | ' Babbage problem
' The quote (') means a comment
' The equals sign (=) means assign
n = 500
' 500 is stored in variable n*n
' 500 because 500*500=250000 less than 269696
' The nitty-gritty is in the 3 lines between "While" and "EndWhile".
' So, we start with 500, n is being incremented by 1 at each round
' while its... | Give a code snippet in #Microsoft_Small_Basic
Charles Babbage, looking ahead to the sorts of problems his Analytical Engine would be able to solve, gave this example:
What is the smallest positive integer whose square ends in the digits 269,696?
— Babbage, letter to Lord Bowden, 1837; see Hollingdale and Tootill,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Window_creation | Window creation | Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| #Processing | Processing |
size(1000,1000);
| Give a code snippet in #Processing
Display a GUI window. The window need not have any contents, but should respond to requests to be closed.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Environment_variables | Environment variables | Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| #11l | 11l | print(os:getenv(‘HOME’)) | Give a code snippet in #11l
Task
Show how to get one of your process's environment variables.
The available variables vary by system; some of the common ones available on Unix include:
PATH
HOME
USER
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Plot_coordinate_pairs | Plot coordinate pairs | Task
Plot a function represented as x, y numerical arrays.
Post the resulting image for the following input arrays (taken from Python's Example section on Time a function):
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
y = {2.7, 2.8, 31.4, 38.1, 58.0, 76.2, 100.5, 130.0, 149.... | #jq | jq | jq -n -M -r -f plot.jq | R CMD BATCH plot.R | Give a code snippet in #jq
Task
Plot a function represented as x, y numerical arrays.
Post the resulting image for the following input arrays (taken from Python's Example section on Time a function):
x = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9};
y = {2.7, 2.8, 31.4, 38.1, 58... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_interpolation_(included) | String interpolation (included) |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Elena | Elena | import extensions;
public program()
{
var s := "little";
console.printLineFormatted("Mary had a {0} lamb.",s).readChar()
} | Give a code snippet in #Elena
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Natural_sorting | Natural sorting |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #Perl | Perl |
use feature 'fc';
use Unicode::Normalize;
sub natural_sort {
my @items = map {
my $str = fc(NFKD($_));
$str =~ s/\s+/ /;
$str =~ s/|^(?:the|a|an) \b|\p{Nonspacing_Mark}| $//g;
my @fields = $str =~ /(?!\z) ([^0-9]*+) ([0-9]*+)/gx;
[$_, \@fields]
} @_;
return map { ... | Give a code snippet in #Perl
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FTP | FTP | Task
Connect to a server, change directory, list its contents and download a file as binary using the FTP protocol. Use passive mode if available.
| #Common_Lisp | Common Lisp | (use-package :ftp)
(with-ftp-connection (conn :hostname "ftp.hq.nasa.gov"
:passive-ftp-p t)
(send-cwd-command conn "/pub/issoutreach/Living in Space Stories (MP3 Files)")
(send-list-command conn t)
(let ((filename "Gravity in the Brain.mp3"))
(retrieve-file conn filename filename... | Give a code snippet in #Common_Lisp
Task
Connect to a server, change directory, list its contents and download a file as binary using the FTP protocol. Use passive mode if available.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Caesar_cipher | Caesar cipher |
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A).
So key 2 encrypts "HI" to... | #GAP | GAP | CaesarCipher := function(s, n)
local r, c, i, lower, upper;
lower := "abcdefghijklmnopqrstuvwxyz";
upper := "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
r := "";
for c in s do
i := Position(lower, c);
if i <> fail then
Add(r, lower[RemInt(i + n - 1, 26) + 1]);
else
i := Position(upper, c);
if i <> fail then
Ad... | Give a code snippet in #GAP
Task
Implement a Caesar cipher, both encoding and decoding.
The key is an integer from 1 to 25.
This cipher rotates (either towards left or right) the letters of the alphabet (A to Z).
The encoding replaces each letter with the 1st to 25th next letter in the alphabet (wrapping Z to A... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #Delphi | Delphi |
function IsNumericString(const inStr: string): Boolean;
var
i: extended;
begin
Result := TryStrToFloat(inStr,i);
end;
| Give a code snippet in #Delphi
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/First-class_functions | First-class functions | A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functions as arguments to other functions
Use functions as retu... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | funcs = {Sin, Cos, #^3 &};
funcsi = {ArcSin, ArcCos, #^(1/3) &};
compositefuncs = Composition @@@ Transpose[{funcs, funcsi}];
Table[i[0.666], {i, compositefuncs}] | Give a code snippet in #Mathematica_.2F_Wolfram_Language
A language has first-class functions if it can do each of the following without recursively invoking a compiler or interpreter or otherwise metaprogramming:
Create new functions from preexisting functions at run-time
Store functions in collections
Use functi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Consecutive_primes_with_ascending_or_descending_differences | Consecutive primes with ascending or descending differences | Task
Find and display here on this page, the longest sequence of consecutive prime numbers where the differences between the primes are strictly ascending.
Do the same for sequences of primes where the differences are strictly descending.
In both cases, show the sequence for primes < 1,000,000.
If there... | #Julia | Julia | using Primes
function primediffseqs(maxnum = 1_000_000)
mprimes = primes(maxnum)
diffs = map(p -> mprimes[p[1] + 1] - p[2], enumerate(@view mprimes[begin:end-1]))
incstart, decstart, bestinclength, bestdeclength = 1, 1, 0, 0
for i in 1:length(diffs)-1
foundinc, founddec = false, false
... | Give a code snippet in #Julia
Task
Find and display here on this page, the longest sequence of consecutive prime numbers where the differences between the primes are strictly ascending.
Do the same for sequences of primes where the differences are strictly descending.
In both cases, show the sequence for prim... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Stack | Stack |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is accessed through its top.
The ba... | #beeswax | beeswax | instruction: _f
gstack: UInt64[0]• (at the beginning of a program lstack is initialized to [0 0 0] | Give a code snippet in #beeswax
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
A stack is a container of elements with last in, first out access policy. Sometimes it also called LIFO.
The stack is ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Speech_synthesis | Speech synthesis | Render the text This is an example of speech synthesis as speech.
Related task
using a speech engine to highlight words
| #Locomotive_Basic | Locomotive Basic | |say,"This is an example of speech synthesis." | Give a code snippet in #Locomotive_Basic
Render the text This is an example of speech synthesis as speech.
Related task
using a speech engine to highlight words
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Test_integerness | Test integerness | Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[edit]
Given a rational, real, or co... | #PicoLisp | PicoLisp |
(de int? (N)
(= N (* 1.0 (/ N 1.0)))) #returns T or NIL
(de integer? (N)
(and (= N (* 1.0 (/ N 1.0))) N)) #returns value of N or NIL
(scl 4) #-> 4 # *Scl the global which holds
1.0 #-> 10000
(int? 1.0) #-> T
(int? 1) #-> NIL # 1 with a scale of 4 is same as 0.0001 which is not an Integer
(int? -1.0) #-> T
(i... | Give a code snippet in #PicoLisp
Mathematically,
the integers Z are included in the rational numbers Q,
which are included in the real numbers R,
which can be generalized to the complex numbers C.
This means that each of those larger sets, and the data types used to represent them, include some integers.
Task[e... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Introspection | Introspection | Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(bloop).
Extra credit
Repor... | #Logo | Logo | show logoversion ; 5.6
if logoversion < 6.0 [print [too old!]]
if and [name? "a] [number? :a] [
print ifelse procedure? "abs [abs :a] [ifelse :a < 0 [minus :a] [:a]]
] | Give a code snippet in #Logo
Task
verify the version/revision of your currently running (compiler/interpreter/byte-compiler/runtime environment/whatever your language uses) and exit if it is too old.
check whether the variable "bloop" exists and whether the math-function "abs()" is available and if yes compute abs(... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CSV_data_manipulation | CSV data manipulation | CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, change some values and save the cha... | #Ursa | Ursa | #
# csv data manipulation
#
# declare a string stream to hold lines
decl string<> lines
# open the file specified on the command line, halting
# execution if they didn't enter one. it will be created if
# it doesn't exist yet
decl file f
if (< (size args) 2)
out "error: please specify a csv file" endl conso... | Give a code snippet in #Ursa
CSV spreadsheet files are suitable for storing tabular data in a relatively portable way.
The CSV format is flexible but somewhat ill-defined.
For present purposes, authors may assume that the data fields contain no commas, backslashes, or quotation marks.
Task
Read a CSV file, chang... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multifactorial | Multifactorial | The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(... | #Common_Lisp | Common Lisp |
(defun mfac (n m)
(reduce #'* (loop for i from n downto 1 by m collect i)))
(loop for i from 1 to 10
do (format t "~2@a: ~{~a~^ ~}~%"
i (loop for j from 1 to 10
collect (mfac j i))))
| Give a code snippet in #Common_Lisp
The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numerical_integration | Numerical integration | Write functions to calculate the definite integral of a function ƒ(x) using all five of the following methods:
rectangular
left
right
midpoint
trapezium
Simpson's
composite
Your functions should take in the upper and lower bounds (a and b), and the number of approximations to make in that range (n).
Assume t... | #E | E | pragma.enable("accumulator")
def leftRect(f, x, h) {
return f(x)
}
def midRect(f, x, h) {
return f(x + h/2)
}
def rightRect(f, x, h) {
return f(x + h)
}
def trapezium(f, x, h) {
return (f(x) + f(x+h)) / 2
}
def simpson(f, x, h) {
return (f(x) + 4 * f(x + h / 2) + f(x+h)) / 6
}
def integrate(f, a, ... | Give a code snippet in #E
Write functions to calculate the definite integral of a function ƒ(x) using all five of the following methods:
rectangular
left
right
midpoint
trapezium
Simpson's
composite
Your functions should take in the upper and lower bounds (a and b), and the number of approximations to make i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hilbert_curve | Hilbert curve |
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| #C.23 | C# | using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Text;
namespace HilbertCurve {
class Program {
static void Swap<T>(ref T a, ref T b) {
var c = a;
a = b;
b = c;
}
struct Point {
public int x, y;
... | Give a code snippet in #C.23
Task
Produce a graphical or ASCII-art representation of a Hilbert curve of at least order 3.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hostname | Hostname | Task
Find the name of the host on which the routine is running.
| #Smalltalk | Smalltalk | OperatingSystem getHostName | Give a code snippet in #Smalltalk
Task
Find the name of the host on which the routine is running.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Web_server | Hello world/Web server | The browser is the new GUI !
Task
Serve our standard text Goodbye, World! to http://localhost:8080/ so that it can be viewed with a web browser.
The provided solution must start or implement a server that accepts multiple client connections and serves text as requested.
Note that starting a web browser or... | #Opa | Opa | server = one_page_server("Hello", -> <>Goodbye, world</>) | Give a code snippet in #Opa
The browser is the new GUI !
Task
Serve our standard text Goodbye, World! to http://localhost:8080/ so that it can be viewed with a web browser.
The provided solution must start or implement a server that accepts multiple client connections and serves text as requested.
Note t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Roman_numerals/Decode | Roman numerals/Decode | Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
starting with the leftmost decima... | #APL | APL | fromRoman←{
rmn←(⎕A,⎕A,'*')[(⎕A,⎕UCS 96+⍳26)⍳⍵] ⍝ make input uppercase
dgt←↑'IVXLCDM' (1 5 10 50 100 500 1000) ⍝ values of roman digits
~rmn∧.∊⊂dgt[1;]:⎕SIGNAL 11 ⍝ domain error if non-roman input
map←dgt[2;dgt[1;]⍳rmn] ⍝ map digits to values
+/map×1-2×(2</map),0 ... | Give a code snippet in #APL
Task
Create a function that takes a Roman numeral as its argument and returns its value as a numeric decimal integer.
You don't need to validate the form of the Roman numeral.
Modern Roman numerals are written by expressing each decimal digit of the number to be encoded separately,
star... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vector_products | Vector products | A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of numbers, (X, Y, Z) would repr... | #Euphoria | Euphoria | constant X = 1, Y = 2, Z = 3
function dot_product(sequence a, sequence b)
return a[X]*b[X] + a[Y]*b[Y] + a[Z]*b[Z]
end function
function cross_product(sequence a, sequence b)
return { a[Y]*b[Z] - a[Z]*b[Y],
a[Z]*b[X] - a[X]*b[Z],
a[X]*b[Y] - a[Y]*b[X] }
end function
function scal... | Give a code snippet in #Euphoria
A vector is defined as having three dimensions as being represented by an ordered collection of three numbers: (X, Y, Z).
If you imagine a graph with the x and y axis being at right angles to each other and having a third, z axis coming out of the page, then a triplet of... | 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... | #Component_Pascal | Component Pascal |
MODULE StringConcatenation;
IMPORT StdLog;
PROCEDURE Do*;
VAR
str1,str2: ARRAY 128 OF CHAR;
BEGIN
str1 := "Hello";
str2 := str1 + " world";
StdLog.String(":> " + str2);StdLog.Ln
END Do;
END StringConcatenation.
| Give a code snippet in #Component_Pascal
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_encoding | URL encoding | Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character encodes into %20 within the string.
Fo... | #UNIX_Shell | UNIX Shell | function urlencode
{
typeset decoded=$1 encoded= rest= c=
typeset rest2= bug='rest2=${rest}'
if [[ -z ${BASH_VERSION} ]]; then
# bug /usr/bin/sh HP-UX 11.00
typeset _decoded='xyz%26xyz'
rest="${_decoded#?}"
c="${_decoded%%${rest}}"
if (( ${#c} != 1 )); then
typeset qm='????????????????????????????????... | Give a code snippet in #UNIX_Shell
Task
Provide a function or mechanism to convert a provided string into URL encoding representation.
In URL encoding, special characters, control characters and extended characters
are converted into a percent symbol followed by a two digit hexadecimal code,
So a space character enc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pentomino_tiling | Pentomino tiling | A pentomino is a polyomino that consists of 5 squares. There are 12 pentomino shapes,
if you don't count rotations and reflections. Most pentominoes can form their own mirror image through
rotation, but some of them have to be flipped over.
I ... | #Python | Python | from itertools import product
minos = (((197123, 7, 6), (1797, 6, 7), (1287, 6, 7), (196867, 7, 6)), ((263937, 6, 6), (197126, 6, 6), (393731, 6, 6), (67332, 6, 6)),
((16843011, 7, 5), (2063, 5, 7), (3841, 5, 7), (271, 5, 7), (3848, 5, 7), (50463234, 7, 5), (50397441, 7, 5), (33686019, 7, 5)),
((13184... | Give a code snippet in #Python
A pentomino is a polyomino that consists of 5 squares. There are 12 pentomino shapes,
if you don't count rotations and reflections. Most pentominoes can form their own mirror image through
rotation, but some of them have to be flipped over.
I ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Maximum_triangle_path_sum | Maximum triangle path sum | Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row:
55
94 48
95 30 96
77 71 26 67
One of such walks is 55 - 94 - 30 - 26.
You... | #Raku | Raku | my $triangle = q| 55
94 48
95 30 96
77 71 26 67
97 13 76 38 45
07 36 79 16 37 68
48 07 09 18 70 26 06
18 72 79 46 59 79 29 90
20 76 87 11 32 07 07 49 18
... | Give a code snippet in #Raku
Starting from the top of a pyramid of numbers like this, you can walk down going one step on the right or on the left, until you reach the bottom row:
55
94 48
95 30 96
77 71 26 67
One of such w... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_is_numeric | Determine if a string is numeric | Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Metrics
Array length
String length
Cop... | #ARM_Assembly | ARM Assembly |
/* ARM assembly Raspberry PI */
/* program strNumber.s */
/* Constantes */
.equ STDIN, 0 @ Linux input console
.equ STDOUT, 1 @ Linux output console
.equ EXIT, 1 @ Linux syscall
.equ READ, 3 @ Linux... | Give a code snippet in #ARM_Assembly
Task
Create a boolean function which takes in a string and tells whether it is a numeric string (floating point and negative numbers included) in the syntax the language uses for numeric literals or numbers converted from strings.
Other tasks related to string operations:
Met... | christopher/rosetta-code | |
http://rosettacode.org/wiki/URL_decoding | URL decoding | This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded form "http://foo bar/".
Th... | #Ruby | Ruby | require 'cgi'
puts CGI.unescape("http%3A%2F%2Ffoo%20bar%2F")
# => "http://foo bar/" | Give a code snippet in #Ruby
This task (the reverse of URL encoding and distinct from URL parser) is to provide a function
or mechanism to convert an URL-encoded string into its original unencoded form.
Test cases
The encoded string "http%3A%2F%2Ffoo%20bar%2F" should be reverted to the unencoded f... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Partition_function_P | Partition function P |
The Partition Function P, often notated P(n) is the number of solutions where n∈ℤ can be expressed as the sum of a set of positive integers.
Example
P(4) = 5 because 4 = Σ(4) = Σ(3,1) = Σ(2,2) = Σ(2,1,1) = Σ(1,1,1,1)
P(n) can be expressed as the recurrence relation:
P(n) = P(n-1) +P(n-2) -P(n-5) -P(n-7)... | #Factor | Factor | USING: kernel lists lists.lazy math sequences sequences.extras ;
! Compute the nth pentagonal number.
: penta ( n -- m ) [ sq 3 * ] [ - 2/ ] bi ;
! An infinite lazy list of indices to add and subtract in the
! sequence of partitions to find the next P.
: seq ( -- list )
1 lfrom [ penta 1 - ] <lazy-map> 1 lfrom ... | Give a code snippet in #Factor
The Partition Function P, often notated P(n) is the number of solutions where n∈ℤ can be expressed as the sum of a set of positive integers.
Example
P(4) = 5 because 4 = Σ(4) = Σ(3,1) = Σ(2,2) = Σ(2,1,1) = Σ(1,1,1,1)
P(n) can be expressed as the recurrence relation:
P(n) ... | 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... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | Sin[1]
Cos[1]
Tan[1]
ArcSin[1]
ArcCos[1]
ArcTan[1]
Sin[90 Degree]
Cos[90 Degree]
Tan[90 Degree] | Give a code snippet in #Mathematica.2FWolfram_Language
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_carpet | Sierpinski carpet | Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ... | #Fennel | Fennel | (fn in-carpet? [x y]
(if
(or (= 0 x) (= 0 y)) true
(and (= 1 (% x 3)) (= 1 (% y 3))) false
(in-carpet? (// x 3) (// y 3))))
(fn make-carpet [size]
(for [y 0 (- (^ 3 size) 1)]
(for [x 0 (- (^ 3 size) 1)]
(if (in-carpet? x y)
(io.write "#")
(io.write " ")))
(io.write "\n"))... | Give a code snippet in #Fennel
Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # #... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitwise_operations | Bitwise operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Robotic | Robotic |
input string "First value"
set "local1" to "input"
input string "Second value"
set "local2" to "input"
. ">>> is an arithmetic shift; >> is a logical shift"
[ "a AND b = ('local1' a 'local2')"
[ "a OR b = ('local1' o 'local2')"
[ "a XOR b = ('local1' x 'local2')"
[ "NOT a = (~'local1')"
[ "a << b = ('local1' << 'lo... | Give a code snippet in #Robotic
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Phrase_reversals | Phrase reversals | Task
Given a string of space separated words containing the following phrase:
rosetta code phrase reversal
Reverse the characters of the string.
Reverse the characters of each individual word in the string, maintaining original word order within the string.
Reverse the order of each word of the string, maintaini... | #MiniScript | MiniScript | phrase = "rosetta code phrase reversal"
// general sequence reversal function
reverse = function(seq)
out = []
for i in range(seq.len-1, 0)
out.push seq[i]
end for
if seq isa string then return out.join("")
return out
end function
// 1. Reverse the characters of the string.
print reverse... | Give a code snippet in #MiniScript
Task
Given a string of space separated words containing the following phrase:
rosetta code phrase reversal
Reverse the characters of the string.
Reverse the characters of each individual word in the string, maintaining original word order within the string.
Reverse the order o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Simulate_input/Mouse | Simulate input/Mouse | #Wren | Wren | /* simulate_input_mouse.wren */
var KeyPressMask = 1 << 0
var ButtonPressMask = 1 << 2
var Button1Mask = 1 << 8
var ExposureMask = 1 << 15
var Button1 = 1
var KeyPress = 2
var ButtonPress = 4
var Expose = 12
var ClientMessage = 33
var XK_a = 0x0061
var XK_q ... | Give a code snippet in #Wren
| christopher/rosetta-code | ||
http://rosettacode.org/wiki/Tokenize_a_string | Tokenize a string | Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks related to string operations:
Me... | #Red | Red | str: "Hello,How,Are,You,Today"
>> tokens: split str ","
>> probe tokens
["Hello" "How" "Are" "You" "Today"]
>> periods: replace/all form tokens " " "." ;The word FORM converts the list series to a string removing quotes.
>> print periods ;then REPLACE/ALL spaces with... | Give a code snippet in #Red
Separate the string "Hello,How,Are,You,Today" by commas into an array (or list) so that each element of it stores a different word.
Display the words to the 'user', in the simplest manner possible, separated by a period.
To simplify, you may display a trailing period.
Other tasks rela... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Wireworld | Wireworld | Wireworld
Conway's Game of Life
It is capable of doing sophisticated computations with appropriate programs
(it is actually Turing complete),
and is much simpler to program for.
A Wireworld arena consists of a Cartesian grid of cells,
each of which can be in one of four states.
All cell transitions happen simultaneous... | #Phix | Phix | --
-- demo\rosetta\Wireworld.exw
-- ==========================
--
-- Invoke with file to read, or let it read the one below (if compiled assumes source is in the same directory)
--
-- Note that tabs in description files are not supported - where necessary spaces can be replaced with _ chars.
-- (tab chars in text fi... | Give a code snippet in #Phix
Wireworld
Conway's Game of Life
It is capable of doing sophisticated computations with appropriate programs
(it is actually Turing complete),
and is much simpler to program for.
A Wireworld arena consists of a Cartesian grid of cells,
each of which can be in one of four states.
All cell t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #Pascal | Pascal | if ($s eq "") { # Test for empty string
print "The string is empty";
}
if ($s ne "") { # Test for non empty string
print "The string is not empty";
} | Give a code snippet in #Pascal
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Ot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/P-Adic_numbers,_basic | P-Adic numbers, basic | Conversion and addition of p-adic Numbers.
Task.
Convert two rationals to p-adic numbers and add them up.
Rational reconstruction is needed to interpret the result.
p-Adic numbers were introduced around 1900 by Hensel. p-Adic expansions
(a series of digits 0 ≤ d < p times p-power weights)
are finite-tailed and tend ... | #Go | Go | package main
import "fmt"
// constants
const EMX = 64 // exponent maximum (if indexing starts at -EMX)
const DMX = 100000 // approximation loop maximum
const AMX = 1048576 // argument maximum
const PMAX = 32749 // prime maximum
// global variables
var p1 = 0
var p = 7 // default prime
var k = 11 // precis... | Give a code snippet in #Go
Conversion and addition of p-adic Numbers.
Task.
Convert two rationals to p-adic numbers and add them up.
Rational reconstruction is needed to interpret the result.
p-Adic numbers were introduced around 1900 by Hensel. p-Adic expansions
(a series of digits 0 ≤ d < p times p-power weights)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Atomic_updates | Atomic updates |
Task
Define a data type consisting of a fixed number of 'buckets', each containing a nonnegative integer value, which supports operations to:
get the current value of any bucket
remove a specified amount from one specified bucket and add it to another, preserving the total of all bucket values, and clamping the t... | #PARI.2FGP | PARI/GP | use strict;
use 5.10.0;
use threads 'yield';
use threads::shared;
my @a :shared = (100) x 10;
my $stop :shared = 0;
sub pick2 {
my $i = int(rand(10));
my $j;
$j = int(rand(10)) until $j != $i;
($i, $j)
}
sub even {
lock @a;
my ($i, $j) = pick2;
my $sum = $a[$i] + $a[$j];
$a[$i] = int($sum / 2);
$a[$j] ... | Give a code snippet in #PARI.2FGP
Task
Define a data type consisting of a fixed number of 'buckets', each containing a nonnegative integer value, which supports operations to:
get the current value of any bucket
remove a specified amount from one specified bucket and add it to another, preserving the total of al... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #zkl | zkl | foreach line in (File("foo.zkl")){print(line)} | Give a code snippet in #zkl
Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Happy_numbers | Happy numbers | From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loops endlessly in a cycle which does not inclu... | #D.C3.A9j.C3.A0_Vu | Déjà Vu | next-num:
0
while over:
over
* dup % swap 10
+
swap floor / swap 10 swap
drop swap
is-happy happies n:
if has happies n:
return happies! n
local :seq set{ n }
n
while /= 1 dup:
next-num
if has seq dup:
drop
set-to happies n false
return false
if has happies dup:
set-to happies n dup... | Give a code snippet in #D.C3.A9j.C3.A0_Vu
From Wikipedia, the free encyclopedia:
A happy number is defined by the following process:
Starting with any positive integer, replace the number by the sum of the squares of its digits, and repeat the process until the number equals 1 (where it will stay), or it loop... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Closures/Value_capture | Closures/Value capture | Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2.
Display the result of runnin... | #OCaml | OCaml | let () =
let cls = Array.init 10 (fun i -> (function () -> i * i)) in
Random.self_init ();
for i = 1 to 6 do
let x = Random.int 9 in
Printf.printf " fun.(%d) = %d\n" x (cls.(x) ());
done | Give a code snippet in #OCaml
Task
Create a list of ten functions, in the simplest manner possible (anonymous functions are encouraged), such that the function at index i (you may choose to start i from either 0 or 1), when run, should return the square of the index, that is, i 2... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #PowerShell | PowerShell |
function BinarySearch-Iterative ([int[]]$Array, [int]$Value)
{
[int]$low = 0
[int]$high = $Array.Count - 1
while ($low -le $high)
{
[int]$mid = ($low + $high) / 2
if ($Array[$mid] -gt $Value)
{
$high = $mid - 1
}
elseif ($Array[$mid] -lt $Value)
... | Give a code snippet in #PowerShell
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a sec... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multifactorial | Multifactorial | The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(... | #Wren | Wren | import "/fmt" for Fmt
var mf = Fn.new { |n, d|
var prod = 1
while (n > 1) {
prod = prod * n
n = n - d
}
return prod
}
for (d in 1..5) {
System.write("degree %(d): ")
for (n in 1..10) System.write(Fmt.d(8, mf.call(n, d)))
System.print()
} | Give a code snippet in #Wren
The factorial of a number, written as
n
!
{\displaystyle n!}
, is defined as
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\displaystyle n!=n(n-1)(n-2)...(2)(1)}
.
Multifactorials generalize factorials as follows:
n
!
=
n
(
n
−
1
)
(
n
−
2
)
.
.
.
(
2
)
(
1
)
{\disp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dragon_curve | Dragon curve |
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followed by a left dragon, at 90-degree an... | #Plain_TeX | Plain TeX | \input tikz.tex
\usetikzlibrary{lindenmayersystems}
\pgfdeclarelindenmayersystem{Dragon curve}{
\symbol{S}{\pgflsystemdrawforward}
\rule{F -> F+S}
\rule{S -> F-S}
}
\tikzpicture
\draw
[lindenmayer system={Dragon curve, step=10pt, axiom=F, order=8}]
lindenmayer system;
\endtikzpicture
\bye | Give a code snippet in #Plain_TeX
Create and display a dragon curve fractal.
(You may either display the curve directly or write it to an image file.)
Algorithms
Here are some brief notes the algorithms used and how they might suit various languages.
Recursively a right curling dragon is a right dragon followe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_three_variables | Sort three variables |
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
... | #CLU | CLU | % Sort three variables.
% The variables must all be of the same type, and the type
% must implement the less-than comparator.
sort_three = proc [T: type] (x,y,z: T) returns (T,T,T)
where T has lt: proctype (T,T) returns (bool)
if y<x then x,y := y,x end
if z<y then y,z := z,y end
if y<x then x,... | Give a code snippet in #CLU
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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 ... | #EasyLang | EasyLang | func fib n . res .
if n < 2
res = n
.
prev = 0
val = 1
for _ range n - 1
res = prev + val
prev = val
val = res
.
.
call fib 36 r
print r | Give a code snippet in #EasyLang
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_a_string | Reverse a string | Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty string (assignment)
Counting
... | #Nim | Nim | import unicode
proc reverse(s: var string) =
for i in 0 .. s.high div 2:
swap(s[i], s[s.high - i])
proc reversed(s: string): string =
result = newString(s.len)
for i,c in s:
result[s.high - i] = c
proc uniReversed(s: string): string =
result = newStringOfCap(s.len)
var tmp: seq[Rune] = @[]
for... | Give a code snippet in #Nim
Task
Take a string and reverse it.
For example, "asdf" becomes "fdsa".
Extra credit
Preserve Unicode combining characters.
For example, "as⃝df̅" becomes "f̅ds⃝a", not "̅fd⃝sa".
Other tasks related to string operations:
Metrics
Array length
String length
Copy a string
Empty s... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Balanced_brackets | Balanced brackets | Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nest.
Examples
(empty) ... | #TMG | TMG | program: readint(n) [n>0] readint(seed)
loop: parse(render) [--n>0?]/done loop;
render: random(i, 15) [i = (i+1)*2] loop2 = { 1 * };
loop2: random(b, 2) ( [b&1?] ={<[>} | ={<]>} ) [--i>0?]/done loop2 = { 2 1 };
done: ;
/* Reads decimal integer */
readint: proc(n;i) string(spaces) [n=0] inta
int1: [... | Give a code snippet in #TMG
Task:
Generate a string with N opening brackets [ and with N closing brackets ], in some arbitrary order.
Determine whether the generated string is balanced; that is, whether it consists entirely of pairs of opening/closing brackets (in that order), none of which mis-nes... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #Erlang | Erlang | -module(beersong).
-export([sing/0]).
-define(TEMPLATE_0, "~s of beer on the wall, ~s of beer.~nGo to the store and buy some more, 99
bottles of beer on the wall.~n").
-define(TEMPLATE_N, "~s of beer on the wall, ~s of beer.~nTake one down and pass it around, ~s of
beer on the wall.~n~n").
create_verse(0) -> {0,... | Give a code snippet in #Erlang
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
9... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Root_mean_square | Averages/Root mean square | Task[edit]
Compute the Root mean square of the numbers 1..10.
The root mean square is also known by its initials RMS (or rms), and as the quadratic mean.
The RMS is calculated as the mean of the squares of the numbers, square-rooted:
x
r
m
s
=
x
1
2
+
x
2
2
+
⋯
+
x
... | #XLISP | XLISP | (defun quadratic-mean (xs)
(sqrt
(/
(apply +
(mapcar (lambda (x) (expt x 2)) xs))
(length xs))))
; define a RANGE function, for testing purposes
(defun range (x y)
(if (< x y)
(cons x (range (+ x 1) y))))
; test QUADRATIC-MEAN
(print (quadratic-mea... | Give a code snippet in #XLISP
Task[edit]
Compute the Root mean square of the numbers 1..10.
The root mean square is also known by its initials RMS (or rms), and as the quadratic mean.
The RMS is calculated as the mean of the squares of the numbers, square-rooted:
x
r
m
s
=
x
1
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pig_the_dice_game | Pig the dice game | The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to their score for that turn and th... | #Racket | Racket |
#lang racket
(define (pig-the-dice #:print? [print? #t] . players)
(define prn (if print? (λ xs (apply printf xs) (flush-output)) void))
(define names (for/list ([p players] [n (in-naturals 1)]) n))
(define points (for/list ([p players]) (box 0)))
(with-handlers ([(negate exn?) identity])
(for ([nm (in-... | Give a code snippet in #Racket
The game of Pig is a multiplayer game played with a single six-sided die. The
object of the game is to reach 100 points or more.
Play is taken in turns. On each person's turn that person has the option of either:
Rolling the dice: where a roll of two to six is added to ... | christopher/rosetta-code | |
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... | #Swift | Swift | func catalan(_ n: Int) -> Int {
switch n {
case 0:
return 1
case _:
return catalan(n - 1) * 2 * (2 * n - 1) / (n + 1)
}
}
for i in 1..<16 {
print("catalan(\(i)) => \(catalan(i))")
}
| Give a code snippet in #Swift
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
!
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_totient_numbers | Perfect totient numbers | Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| #Racket | Racket |
#lang racket
(require math/number-theory)
(define (tot n)
(match n
[1 0]
[n (define t (totient n))
(+ t (tot t))]))
(define (perfect? n)
(= n (tot n)))
(define-values (ns i)
(for/fold ([ns '()] [i 0])
([n (in-naturals 1)]
#:break (= i 20)
#:when (perfec... | Give a code snippet in #Racket
Generate and show here, the first twenty Perfect totient numbers.
Related task
Totient function
Also see
the OEIS entry for perfect totient numbers.
mrob list of the first 54
| christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTP | HTTP | Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| #Ada | Ada |
with Ada.Text_IO; use Ada.Text_IO;
with AWS.Client;
with AWS.Response;
procedure HTTP_Request is
begin
Put_Line (AWS.Response.Message_Body (AWS.Client.Get (URL => "http://www.rosettacode.org")));
end HTTP_Request;
| Give a code snippet in #Ada
Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #ATS | ATS | ; Create an associative array
obj := Object("red", 0xFF0000, "blue", 0x0000FF, "green", 0x00FF00)
enum := obj._NewEnum()
While enum[key, value]
t .= key "=" value "`n"
MsgBox % t | Give a code snippet in #ATS
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #.D0.9C.D0.9A-61.2F52 | МК-61/52 | П1 П2 <-> П0
ИП0 1 - x#0 29
ИП1 2 * П1
ИП0 2 / [x] П0
2 / {x} x#0 04 ИП2 ИП1 + П2
БП 04
ИП2 С/П | Give a code snippet in #.D0.9C.D0.9A-61.2F52
Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any re... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Wilson_primes_of_order_n | Wilson primes of order n | Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
Task
Calculate and show on thi... | #Rust | Rust | // [dependencies]
// rug = "1.13.0"
use rug::Integer;
fn generate_primes(limit: usize) -> Vec<usize> {
let mut sieve = vec![true; limit >> 1];
let mut p = 3;
let mut sq = p * p;
while sq < limit {
if sieve[p >> 1] {
let mut q = sq;
while q < limit {
si... | Give a code snippet in #Rust
Definition
A Wilson prime of order n is a prime number p such that p2 exactly divides:
(n − 1)! × (p − n)! − (− 1)n
If n is 1, the latter formula reduces to the more familiar: (p - n)! + 1 where the only known examples for p are 5, 13, and 563.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_a_Mersenne_number | Factors of a Mersenne number | A Mersenne number is a number in the form of 2P-1.
If P is prime, the Mersenne number may be a Mersenne prime
(if P is not prime, the Mersenne number is also not prime).
In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before starting a, potentially lengthy,... | #GAP | GAP | MersenneSmallFactor := function(n)
local k, m, d;
if IsPrime(n) then
d := 2*n;
m := 1;
for k in [1 .. 1000000] do
m := m + d;
if PowerModInt(2, n, m) = 1 then
return m;
fi;
od;
fi;
return fail;
end;
# If n is not pri... | Give a code snippet in #GAP
A Mersenne number is a number in the form of 2P-1.
If P is prime, the Mersenne number may be a Mersenne prime
(if P is not prime, the Mersenne number is also not prime).
In the search for Mersenne prime numbers it is advantageous to eliminate exponents by finding a small factor before sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Barnsley_fern | Barnsley fern |
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 yn
ƒ2 (chosen 85% of the time)
... | #FreeBASIC | FreeBASIC | ' version 10-10-2016
' compile with: fbc -s console
Sub barnsley(height As UInteger)
Dim As Double x, y, xn, yn
Dim As Double f = height / 10.6
Dim As UInteger offset_x = height \ 4 - height \ 40
Dim As UInteger n, r
ScreenRes height \ 2, height, 32
For n = 1 To height * 50
r = Int(Rnd * 100) ... | Give a code snippet in #FreeBASIC
A Barnsley fern is a fractal named after British mathematician Michael Barnsley and can be created using an iterated function system (IFS).
Task
Create this fractal fern, using the following transformations:
ƒ1 (chosen 1% of the time)
xn + 1 = 0
yn + 1 = 0.16 ... | christopher/rosetta-code |
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