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
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|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Formatted_numeric_output | Formatted numeric output | Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| #min | min | (quote cons "" join) :str-append
(pick length - repeat swap str-append) :left-pad
7.125 string "0" 9 left-pad puts! | Give a code snippet in #min
Task
Express a number in decimal as a fixed-length string with leading zeros.
For example, the number 7.125 could be expressed as 00007.125.
| 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 ... | #Lua | Lua |
--calculates the nth fibonacci number. Breaks for negative or non-integer n.
function fibs(n)
return n < 2 and n or fibs(n - 1) + fibs(n - 2)
end
| Give a code snippet in #Lua
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 g... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Perfect_numbers | Perfect numbers | Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself).
Note: The faster Luca... | #Ring | Ring |
for i = 1 to 10000
if perfect(i) see i + nl ok
next
func perfect n
sum = 0
for i = 1 to n - 1
if n % i = 0 sum = sum + i ok
next
if sum = n return 1 else return 0 ok
return sum
| Give a code snippet in #Ring
Write a function which says whether a number is perfect.
A perfect number is a positive integer that is the sum of its proper positive divisors excluding the number itself.
Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Ordered_words | Ordered words | An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locally assume that you have download... | #Ada | Ada |
with Ada.Text_IO, Ada.Containers.Indefinite_Vectors;
use Ada.Text_IO;
procedure Ordered_Words is
package Word_Vectors is new Ada.Containers.Indefinite_Vectors
(Index_Type => Positive, Element_Type => String);
use Word_Vectors;
File : File_Type;
Ordered_Words : Vector;
Max_Length : Positive := ... | Give a code snippet in #Ada
An ordered word is a word in which the letters appear in alphabetic order.
Examples include abbey and dirt.
Task[edit]
Find and display all the ordered words in the dictionary unixdict.txt that have the longest word length.
(Examples that access the dictionary file locally ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zig-zag_matrix | Zig-zag matrix | Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encode images).
For example, gi... | #Ksh | Ksh |
#!/bin/ksh
# Produce a zig-zag array.
# # Variables:
#
integer DEF_SIZE=5 # Default size = 5
arr_size=${1:-$DEF_SIZE} # $1 = size, or default
# # Externals:
#
# # Functions:
#
######
# main #
######
integer i j n
typeset -a zzarr
for (( i=n=0; i<arr_size*2; i++ )); do
for (( j= (i<arr_size)... | Give a code snippet in #Ksh
Task
Produce a zig-zag array.
A zig-zag array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you zig-zag along the array's anti-diagonals.
For a graphical representation, see JPG zigzag (JPG uses such arrays to encod... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fibonacci_sequence | Fibonacci sequence | The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions are generally considered too slow ... | #PL.2FpgSQL | PL/pgSQL | CREATE OR REPLACE FUNCTION fib(n INTEGER) RETURNS INTEGER AS $$
BEGIN
IF (n < 2) THEN
RETURN n;
END IF;
RETURN fib(n - 1) + fib(n - 2);
END;
$$ LANGUAGE plpgsql; | Give a code snippet in #PL.2FpgSQL
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 solution... | 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.
| #XSLT | XSLT | <xsl:for-each select="nodes[@value mod 2 = 0]">
<xsl:value-of select="@value" />
</xsl:for-each> | Give a code snippet in #XSLT
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/Compare_a_list_of_strings | Compare a list of strings | Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false value, which could be used as t... | #Ada | Ada | package String_Vec is new Ada.Containers.Indefinite_Vectors
(Index_Type => Positive, Element_Type => String);
use type String_Vec.Vector; | Give a code snippet in #Ada
Task
Given a list of arbitrarily many strings, show how to:
test if they are all lexically equal
test if every string is lexically less than the one after it (i.e. whether the list is in strict ascending order)
Each of those two tests should result in a single true or false va... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Discordian_date | Discordian date |
Task
Convert a given date from the Gregorian calendar to the Discordian calendar.
| #Befunge | Befunge | 0" :raeY">:#,_&>\" :htnoM">:#,_&>04p" :yaD">:#,_$&>55+,1-:47*v
v"f I".+1%,,,,"Day I":$_:#<0#!4#:p#-4#1g4-#0+#<<_v#!*!-2g40!-<
>"o",,,/:5+*66++:4>g#<:#44#:9#+*#1-#,_$$0 v_v#!< >$ 0 "yaD " v
@,+55.+*+92"j"$_,#!>#:<", in the YOLD"*84 <.>,:^ :"St. Tib's"<
$# #"#"##"#"Chaos$Discord$Confusion$Bureaucracy$The Aftermath$ | Give a code snippet in #Befunge
Task
Convert a given date from the Gregorian calendar to the Discordian calendar.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bogosort | Sorting algorithms/Bogosort |
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
... | #Qi | Qi |
(define remove-element
0 [_ | R] -> R
Pos [A | R] -> [A | (remove-element (1- Pos) R)])
(define get-element
Pos R -> (nth (1+ Pos) R))
(define shuffle-0
Pos R -> [(get-element Pos R) | (shuffle (remove-element Pos R))])
(define shuffle
[] -> []
R -> (shuffle-0 (RANDOM (length R)) R))
(define in... | Give a code snippet in #Qi
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/100_doors | 100 doors | There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ...), and toggle it.
The third... | #S-BASIC | S-BASIC |
$constant DOOR_OPEN = 1
$constant DOOR_CLOSED = 0
$constant MAX_DOORS = 100
var i, j = integer
dim integer doors(MAX_DOORS)
rem - all doors are initially closed
for i = 1 to MAX_DOORS
doors(i) = DOOR_CLOSED
next i
rem - cycle through at increasing intervals and flip doors
for i = 1 to MAX_DOORS
for j = i to... | Give a code snippet in #S-BASIC
There are 100 doors in a row that are all initially closed.
You make 100 passes by the doors.
The first time through, visit every door and toggle the door (if the door is closed, open it; if it is open, close it).
The second time, only visit every 2nd door (door #2, #4, #6, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Web_scraping | Web scraping | Task
Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off this page's talk page.
If possible,... | #Julia | Julia | using Requests, Printf
function getusnotime()
const url = "http://tycho.usno.navy.mil/timer.pl"
s = try
get(url)
catch err
@sprintf "get(%s)\n => %s" url err
end
isa(s, Requests.Response) || return (s, false)
t = match(r"(?<=<BR>)(.*?UTC)", readstring(s))
isa(t, Regex... | Give a code snippet in #Julia
Task
Create a program that downloads the time from this URL: http://tycho.usno.navy.mil/cgi-bin/timer.pl and then prints the current UTC time by extracting just the UTC time from the web page's HTML. Alternatively, if the above url is not working, grab the first date/time off this pa... | 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)... | #C.2B.2B | C++ | #include <chrono>
#include <iostream>
#include <vector>
#include <gmpxx.h>
using big_int = mpz_class;
big_int partitions(int n) {
std::vector<big_int> p(n + 1);
p[0] = 1;
for (int i = 1; i <= n; ++i) {
for (int k = 1;; ++k) {
int j = (k * (3*k - 1))/2;
if (j > i)
... | Give a code snippet in #C.2B.2B
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/Word_wrap | Word wrap | Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or provided in a standard library, sho... | #Clojure | Clojure | ;; Wrap line naive version
(defn wrap-line [size text]
(loop [left size line [] lines []
words (clojure.string/split text #"\s+")]
(if-let [word (first words)]
(let [wlen (count word)
spacing (if (== left size) "" " ")
alen (+ (count spacing) wlen)]
(if (<= alen left... | Give a code snippet in #Clojure
Even today, with proportional fonts and complex layouts, there are still cases where you need to wrap text at a specified column.
Basic task
The basic task is to wrap a paragraph of text in a simple way in your language.
If there is a way to do this that is built-in, trivial, or pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Identity_matrix | Identity matrix | Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
0
1
⋯
0
⋮
⋮
⋮
⋱
... | #ooRexx | ooRexx |
say "a 3x3 identity matrix"
say
call printMatrix createIdentityMatrix(3)
say
say "a 5x5 identity matrix"
say
call printMatrix createIdentityMatrix(5)
::routine createIdentityMatrix
use arg size
matrix = .array~new(size, size)
loop i = 1 to size
loop j = 1 to size
if i == j then matrix[i, j] = ... | Give a code snippet in #ooRexx
Task
Build an identity matrix of a size known at run-time.
An identity matrix is a square matrix of size n × n,
where the diagonal elements are all 1s (ones),
and all the other elements are all 0s (zeroes).
I
n
=
[
1
0
0
⋯
0
0
1
0
⋯
0
0
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rep-string | Rep-string | Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at least twice in the original.
For e... | #PicoLisp | PicoLisp | (de repString (Str)
(let Lst (chop Str)
(for (N (/ (length Lst) 2) (gt0 N) (dec N))
(T
(use (Lst X)
(let H (cut N 'Lst)
(loop
(setq X (cut N 'Lst))
(NIL (head X H))
(NIL Lst T) ) ) )
... | Give a code snippet in #PicoLisp
Given a series of ones and zeroes in a string, define a repeated string or rep-string as a string which is created by repeating a substring of the first N characters of the string truncated on the right to the length of the input string, and in which the substring appears repeated at l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_definition | Function definition | A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract from showing how functions are ... | #Cowgol | Cowgol | sub multiply(a: int32, b: int32): (rslt: int32) is
rslt := a * b;
end sub | Give a code snippet in #Cowgol
A function is a body of code that returns a value.
The value returned may depend on arguments provided to the function.
Task
Write a definition of a function called "multiply" that takes two arguments and returns their product.
(Argument types should be chosen so as not to distract... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_a_set_of_characters_from_a_string | Strip a set of characters from a string | Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in the second argument:
print str... | #Clojure | Clojure | (defn strip [coll chars]
(apply str (remove #((set chars) %) coll)))
(strip "She was a soul stripper. She took my heart!" "aei")
;; => "Sh ws soul strppr. Sh took my hrt!" | Give a code snippet in #Clojure
Task
Create a function that strips a set of characters from a string.
The function should take two arguments:
a string to be stripped
a string containing the set of characters to be stripped
The returned string should contain the first string, stripped of any characters in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic/Integer | Arithmetic/Integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #AppleScript | AppleScript | set i1 to (text returned of (display dialog "Enter an integer value" default answer "")) as integer
set i2 to (text returned of (display dialog "Enter another integer value" default answer "")) as integer
set sum to i1 + i2
set diff to i1 - i2
set prod to i1 * i2
set quot to i1 div i2 -- Rounds towards zero.
set rema... | Give a code snippet in #AppleScript
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 Opera... | 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... | #ERRE | ERRE |
PROGRAM ROMAN2ARAB
DIM R%[7]
PROCEDURE TOARAB(ROMAN$->ANS%)
LOCAL I%,J%,P%,N%
FOR I%=LEN(ROMAN$) TO 1 STEP -1 DO
J%=INSTR("IVXLCDM",MID$(ROMAN$,I%,1))
IF J%=0 THEN
ANS%=-9999 ! illegal character
EXIT PROCEDURE
END IF
IF J%>=P% THEN
N... | Give a code snippet in #ERRE
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,
sta... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_multiples_of_3_and_5 | Sum multiples of 3 and 5 | Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| #F.23 | F# |
let sum35 n = Seq.init n (id) |> Seq.reduce (fun sum i -> if i % 3 = 0 || i % 5 = 0 then sum + i else sum)
printfn "%d" (sum35 1000)
printfn "----------"
let sumUpTo (n : bigint) = n * (n + 1I) / 2I
let sumMultsBelow k n = k * (sumUpTo ((n-1I)/k))
let sum35fast n = (sumMultsBelow 3I n) + (sumMultsBelow 5I n) ... | Give a code snippet in #F.23
Task
The objective is to write a function that finds the sum of all positive multiples of 3 or 5 below n.
Show output for n = 1000.
This is is the same as Project Euler problem 1.
Extra credit: do this efficiently for n = 1e20 or higher.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Conditional_structures | Conditional structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Common conditional structures include ... | #Verilog | Verilog |
if( expr_booleana ) command1;
else command2;
| Give a code snippet in #Verilog
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
List the conditional structures offered by a programming language. See Wikipedia: conditionals for descriptions.
Commo... | 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... | #EchoLisp | EchoLisp |
(lib 'bigint)
(define a 2988348162058574136915891421498819466320163312926952423791023078876139)
(define b 2351399303373464486466122544523690094744975233415544072992656881240319)
(define m 1e40)
(powmod a b m)
→ 1527229998585248450016808958343740453059
;; powmod is a native function
;; it could be defined as... | Give a code snippet in #EchoLisp
Find the last 40 decimal digits of
a
b
{\displaystyle a^{b}}
, where
a
=
2988348162058574136915891421498819466320163312926952423791023078876139
{\displaystyle a=2988348162058574136915891421498819466320163312926952423791023078876139}
b
=
23513993033... | christopher/rosetta-code | |
http://rosettacode.org/wiki/CRC-32 | CRC-32 |
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the initial CRC to FFFFFFFF16, and... | #Phix | Phix | with javascript_semantics
sequence table
bool have_table = false
function crc32(string s)
if not have_table then
have_table = true
table = repeat(0,256)
for i=0 to 255 do
atom rem = i
for j=1 to 8 do
if and_bits(rem,1) then
rem = ... | Give a code snippet in #Phix
Task
Demonstrate a method of deriving the Cyclic Redundancy Check from within the language.
The result should be in accordance with ISO 3309, ITU-T V.42, Gzip and PNG.
Algorithms are described on Computation of CRC in Wikipedia.
This variant of CRC-32 uses LSB-first order, sets the ... | christopher/rosetta-code | |
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... | #Rust | Rust | extern crate libc;
//c function that returns the sum of two integers
extern {
fn add_input(in1: libc::c_int, in2: libc::c_int) -> libc::c_int;
}
fn main() {
let (in1, in2) = (5, 4);
let output = unsafe {
add_input(in1, in2) };
assert!( (output == (in1 + in2) ),"Error in sum calculation") ;
} | Give a code snippet in #Rust
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 b... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Include_a_file | Include a file | Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| #m4 | m4 | include(filename) | Give a code snippet in #m4
Task
Demonstrate the language's ability to include source code from other files.
See Also
Compiler/Simple file inclusion pre processor
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Hamming_numbers | Hamming numbers | Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming numbers, in increasing order. In ... | #AWK | AWK |
# syntax: gawk -M -f hamming_numbers.awk
BEGIN {
for (i=1; i<=20; i++) {
printf("%d ",hamming(i))
}
printf("\n1691: %d\n",hamming(1691))
printf("\n1000000: %d\n",hamming(1000000))
exit(0)
}
function hamming(limit, h,i,j,k,n,x2,x3,x5) {
h[0] = 1
x2 = 2
x3 = 3
x5 = 5
for (... | Give a code snippet in #AWK
Hamming numbers are numbers of the form
H = 2i × 3j × 5k
where
i, j, k ≥ 0
Hamming numbers are also known as ugly numbers and also 5-smooth numbers (numbers whose prime divisors are less or equal to 5).
Task
Generate the sequence of Hamming number... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_a_series | Sum of a series | Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
n
1
k
2
{\displa... | #ML | ML |
(* 1.64393456668 *)
List.foldl op+ 0.0 (List.tabulate(1000, fn x => 1.0 / Math.pow(real(x + 1),2.0)))
| Give a code snippet in #ML
Compute the nth term of a series, i.e. the sum of the n first terms of the corresponding sequence.
Informally this value, or its limit when n tends to infinity, is also called the sum of the series, thus the title of this task.
For this task, use:
S
n
=
∑
k
=
1
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pragmatic_directives | Pragmatic directives | Pragmatic directives cause the language to operate in a specific manner, allowing support for operational variances within the program code (possibly by the loading of specific or alternative modules).
Task
List any pragmatic directives supported by the language, and demonstrate how to activate and deactivate... | #PicoLisp | PicoLisp | declare (t(100),i) fixed binary;
i=101;
t(i)=0; | Give a code snippet in #PicoLisp
Pragmatic directives cause the language to operate in a specific manner, allowing support for operational variances within the program code (possibly by the loading of specific or alternative modules).
Task
List any pragmatic directives supported by the language, and demonstr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Holidays_related_to_Easter | Holidays related to Easter | Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and for
years 2010 to 2020 CE.
Note
... | #Kotlin | Kotlin | // version 1.1.2
import java.util.Calendar
import java.util.GregorianCalendar
val holidayOffsets = listOf(
"Easter" to 0,
"Ascension" to 39,
"Pentecost" to 49,
"Trinity" to 56,
"C/Christi" to 60
)
fun String.padCenter(n: Int): String {
val len = this.length
if (n <= len) return this... | Give a code snippet in #Kotlin
Task
Calculate the dates of:
Easter
Ascension Thursday
Pentecost
Trinity Sunday
Corpus Christi feast (for Catholic)
All Saints' Sunday (for Orthodox)
As an example, calculate for the first year of each century from;
years 400 to 2100 CE and for
yea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Foreach | Loops/Foreach | Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for... | #Plain_English | Plain English | To run:
Start up.
Create a list.
Write each entry in the list to the console.
Destroy the list.
Wait for the escape key.
Shut down.
An entry is a thing with a number.
A list is some entries.
To add a number to a list:
Allocate memory for an entry.
Put the number into the entry's number.
Append the entry to the li... | Give a code snippet in #Plain_English
Loop through and print each element in a collection in order.
Use your language's "for each" loop if it has one, otherwise iterate through the collection in order with some other loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Knapsack_problem/0-1 | Knapsack problem/0-1 | A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and it will have to last the whole day.
He cre... | #Forth | Forth |
\ Rosetta Code Knapp-sack 0-1 problem. Tested under GForth 0.7.3.
\ 22 items. On current processors a set fits nicely in one CELL (32 or 64 bits).
\ Brute force approach: for every possible set of 22 items,
\ check for admissible solution then for optimal set.
: offs HERE over - ;
400 VALUE WLIMIT
... | Give a code snippet in #Forth
A tourist wants to make a good trip at the weekend with his friends.
They will go to the mountains to see the wonders of nature, so he needs to pack well for the trip.
He has a good knapsack for carrying things, but knows that he can carry a maximum of only 4kg in it, and it will have... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Subtractive_generator | Subtractive generator | A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{\pmod {m}}}
for some fixed values of... | #uBasic.2F4tH | uBasic/4tH | Push 292929 : Gosub 100 : d = Pop()
For i = 1 To 10
Push 0 : Gosub 100
Print Pop()
Next
End
100 s = Pop()
If s = 0 Then
p = (p + 1) % 55
@(p) = @(p) - @((p + 31) % 55)
If @(p) < 0 Then
@(p) = @(p) + 1000000000
Endif
Push (@(p)) : Return
Endif
@(54) = ... | Give a code snippet in #uBasic.2F4tH
A subtractive generator calculates a sequence of random numbers, where each number is congruent to the subtraction of two previous numbers from the sequence.
The formula is
r
n
=
r
(
n
−
i
)
−
r
(
n
−
j
)
(
mod
m
)
{\displaystyle r_{n}=r_{(n-i)}-r_{(n-j)}{... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Mutual_recursion | Mutual recursion | Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n
)
=
n
−
M
(
F
(
n
−
1
)
)
,
... | #Elixir | Elixir | defmodule MutualRecursion do
def f(0), do: 1
def f(n), do: n - m(f(n - 1))
def m(0), do: 0
def m(n), do: n - f(m(n - 1))
end
IO.inspect Enum.map(0..19, fn n -> MutualRecursion.f(n) end)
IO.inspect Enum.map(0..19, fn n -> MutualRecursion.m(n) end) | Give a code snippet in #Elixir
Two functions are said to be mutually recursive if the first calls the second,
and in turn the second calls the first.
Write two mutually recursive functions that compute members of the Hofstadter Female and Male sequences defined as:
F
(
0
)
=
1
;
M
(
0
)
=
0
F
(
n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial_base_numbers_indexing_permutations_of_a_collection | Factorial base numbers indexing permutations of a collection | You need a random arrangement of a deck of cards, you are sick of lame ways of doing this. This task is a super-cool way of doing this using factorial base numbers.
The first 25 factorial base numbers in increasing order are: 0.0.0, 0.0.1, 0.1.0, 0.1.1, 0.2.0, 0.2.1, 1.0.0, 1.0.1, 1.1.0, 1.1.1,1.2.0, 1.2.1, 2.0.0, 2.0.... | #Wren | Wren | import "random" for Random
import "/math" for Int
import "/fmt" for Fmt
var genFactBaseNums = Fn.new { |size, countOnly|
var results = []
var count = 0
var n = 0
while (true) {
var radix = 2
var res = null
if (!countOnly) res = List.filled(size, 0)
var k = n
wh... | Give a code snippet in #Wren
You need a random arrangement of a deck of cards, you are sick of lame ways of doing this. This task is a super-cool way of doing this using factorial base numbers.
The first 25 factorial base numbers in increasing order are: 0.0.0, 0.0.1, 0.1.0, 0.1.1, 0.2.0, 0.2.1, 1.0.0, 1.0.1, 1.1.0, 1... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Extend_your_language | Extend your language | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. by using macros), other langua... | #F.23 | F# |
// Extend your language. Nigel Galloway: September 14th., 2021
type elsetf=TF
type elseft=FT
type elseff=FF
let elsetf,elseft,elseff=TF,FT,FF
let if2 n g tt (TF:elsetf)tf (FT:elseft)ft (FF:elseff)ff=match(n,g) with (true,true)->tt() |(true,false)->tf() |(false,true)->ft() |_->ff()
if2 (13<23) (23<42) (fun()->printfn ... | Give a code snippet in #F.23
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Some programming languages allow you to extend the language. While this can be done to a certain degree in most languages (e.g. ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One_of_n_lines_in_a_file | One of n lines in a file | A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second line of the file if possible and m... | #Maple | Maple |
with(RandomTools[MersenneTwister]);
one_of_n_lines_in_a_file := proc(fn)
local fid, N, n, L, l, line;
fid := fopen(fn,'READ');
if fid<0 then
return;
end if;
N := 0;
n := 1;
while not feof(fid) do
N := N+1;
L := FileTools[Text][ReadLine](fid);
if (N*GenerateFloat() < 1) then
n := N;
line := L... | Give a code snippet in #Maple
A method of choosing a line randomly from a file:
Without reading the file more than once
When substantial parts of the file cannot be held in memory
Without knowing how many lines are in the file
Is to:
keep the first line of the file as a possible choice, then
Read the second lin... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_intersection_of_a_line_with_a_plane | Find the intersection of a line with a plane | Finding the intersection of an infinite ray with a plane in 3D is an important topic in collision detection.
Task
Find the point of intersection for the infinite ray with direction (0, -1, -1) passing through position (0, 0, 10) with the infinite plane with a normal vector of (0, 0, 1) and which passes ... | #Raku | Raku | class Line {
has $.P0; # point
has $.u⃗; # ray
}
class Plane {
has $.V0; # point
has $.n⃗; # normal
}
sub infix:<∙> ( @a, @b where +@a == +@b ) { [+] @a «*» @b } # dot product
sub line-plane-intersection ($𝑳, $𝑷) {
my $cos = $𝑷.n⃗ ∙ $𝑳.u⃗; # cosine between normal & ray
return 'Vectors ... | Give a code snippet in #Raku
Finding the intersection of an infinite ray with a plane in 3D is an important topic in collision detection.
Task
Find the point of intersection for the infinite ray with direction (0, -1, -1) passing through position (0, 0, 10) with the infinite plane with a normal vector of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncate_a_file | Truncate a file | Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by creating a temporary file of a reduced... | #PARI.2FGP | PARI/GP | install("truncate", "isL", "trunc")
trunc("/tmp/test.file", 20) | Give a code snippet in #PARI.2FGP
Task
Truncate a file to a specific length. This should be implemented as a routine that takes two parameters: the filename and the required file length (in bytes).
Truncation can be achieved using system or library calls intended for such a task, if such methods exist, or by cre... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Reverse_words_in_a_string | Reverse words in a string | Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by spaces (formally, white-space); t... | #FreeBASIC | FreeBASIC | ' FB 1.05.0 Win64
Sub split (s As String, sepList As String, result() As String, removeEmpty As Boolean = False)
If s = "" OrElse sepList = "" Then
Redim result(0)
result(0) = s
Return
End If
Dim As Integer i, j, count = 0, empty = 0, length
Dim As Integer position(Len(s) + 1)
position(0) = ... | Give a code snippet in #FreeBASIC
Task
Reverse the order of all tokens in each of a number of strings and display the result; the order of characters within a token should not be modified.
Example
Hey you, Bub! would be shown reversed as: Bub! you, Hey
Tokens are any non-space characters separated by ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_of_squares | Sum of squares | Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| #11l | 11l | print(sum([1, 2, 3, 4, 5].map(x -> x^2))) | Give a code snippet in #11l
Task
Write a program to find the sum of squares of a numeric vector.
The program should work on a zero-length vector (with an answer of 0).
Related task
Mean
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Heronian_triangles | Heronian triangles | Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b
+
c
2
.
{\displaystyle s... | #Go | Go | package main
import (
"fmt"
"math"
"sort"
)
const (
n = 200
header = "\nSides P A"
)
func gcd(a, b int) int {
leftover := 1
var dividend, divisor int
if (a > b) { dividend, divisor = a, b } else { dividend, divisor = b, a }
for (leftover != 0) {
leftover = ... | Give a code snippet in #Go
Hero's formula for the area of a triangle given the length of its three sides a, b, and c is given by:
A
=
s
(
s
−
a
)
(
s
−
b
)
(
s
−
c
)
,
{\displaystyle A={\sqrt {s(s-a)(s-b)(s-c)}},}
where s is half the perimeter of the triangle; that is,
s
=
a
+
b
+... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Miller%E2%80%93Rabin_primality_test | Miller–Rabin primality test |
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primality test or Rabin–Miller prima... | #REXX | REXX | /*REXX program puts the Miller─Rabin primality test through its paces. */
parse arg limit times seed . /*obtain optional arguments from the CL*/
if limit=='' | limit=="," then limit= 1000 /*Not specified? Then use the default.*/
if times=='' | times=="," then times= 10 ... | Give a code snippet in #REXX
This page uses content from Wikipedia. The original article was at Miller–Rabin primality test. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
The Miller–Rabin primal... | 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... | #Red | Red | >> dehex "http%3A%2F%2Ffoo%20bar%2F"
== "http://foo bar/"
>> dehex "google.com/search?q=%60Abdu%27l-Bah%C3%A1"
== "google.com/search?q=`Abdu'l-Bahá" | Give a code snippet in #Red
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 fo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rate_counter | Rate counter | Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplish these goals:
Run N seconds worth... | #Jsish | Jsish | #!/usr/bin/env jsish
"use strict";
/* Rate counter, timer access, in Jsish */
/* System time in milliseconds */
var runs = 0, newMs;
function countJobsIsTheJob() { runs += 1; }
var milliSeconds = strptime();
while ((newMs = strptime()) < (milliSeconds + 1000)) { countJobsIsTheJob(); }
puts(runs, 'runs in', newMs - mi... | Give a code snippet in #Jsish
Of interest is the code that performs the actual measurements. Any other code (such as job implementation or dispatching) that is required to demonstrate the rate tracking is helpful, but not the focus.
Multiple approaches are allowed (even preferable), so long as they can accomplish the... | 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... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | HailstoneF[n_] := NestWhileList[If[OddQ[#], 3 # + 1, #/2] &, n, # > 1 &] | Give a code snippet in #Mathematica_.2F_Wolfram_Language
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Jensen%27s_Device | Jensen's Device | Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the ALGOL 60 Report.
The following pr... | #FreeBASIC | FreeBASIC | Sub Evaluation
Dim As Integer i, lo = 1, hi = 100
Dim As Double temp = 0
For i = lo To hi
temp += (1/i) ''r(i)
Next i
Print temp
End Sub
Evaluation
Sleep | Give a code snippet in #FreeBASIC
Jensen's Device
You are encouraged to solve this task according to the task description, using any language you may know.
This task is an exercise in call by name.
Jensen's Device is a computer programming technique devised by Danish computer scientist Jørn Jensen after studying the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_matching | String matching |
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 |... | #K | K | startswith: {:[0<#p:_ss[x;y];~*p;0]}
endswith: {0=(-#y)+(#x)-*_ss[x;y]}
contains: {0<#_ss[x;y]} | Give a code snippet in #K
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
Conc... | 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
... | #Bracmat | Bracmat | ( reverse
= L x
. :?L
& @( !arg
: ?
( %?x
& utf$!x
& !x !L:?L
& ~`
)
?
)
| str$!L
)
& out$reverse$Ελληνικά | Give a code snippet in #Bracmat
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
Emp... | christopher/rosetta-code | |
http://rosettacode.org/wiki/100_prisoners | 100 prisoners |
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners start outside the room
They can decid... | #Processing | Processing | IntList drawers = new IntList();
int trials = 100000;
int succes_count;
void setup() {
for (int i = 0; i < 100; i++) {
drawers.append(i);
}
println(trials + " trials\n");
//Random strategy
println("Random strategy");
succes_count = trials;
for (int i = 0; i < trials; i++) {
drawers.shuffle();
... | Give a code snippet in #Processing
The Problem
100 prisoners are individually numbered 1 to 100
A room having a cupboard of 100 opaque drawers numbered 1 to 100, that cannot be seen from outside.
Cards numbered 1 to 100 are placed randomly, one to a drawer, and the drawers all closed; at the start.
Prisoners st... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Literals/String | Literals/String | Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
Here document
Other tasks r... | #Julia | Julia | greet = "Hello"
whom = "world"
greet * ", " * whom * "." | Give a code snippet in #Julia
Task
Show literal specification of characters and strings.
If supported, show how the following work:
verbatim strings (quotes where escape sequences are quoted literally)
here-strings
Also, discuss which quotes expand variables.
Related tasks
Special characters
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Unbias_a_random_generator | Unbias a random generator |
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random number generator to create a function/method/sub... | #Elena | Elena | import extensions;
extension op : IntNumber
{
bool randN()
= randomGenerator.nextInt(self) == 0;
get bool Unbiased()
{
bool flip1 := self.randN();
bool flip2 := self.randN();
while (flip1 == flip2)
{
flip1 := self.randN();
flip2 := self.r... | Give a code snippet in #Elena
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
P
0
{\displaystyle P_{0}}
P
0
{\displaystyle P_{0}}
P
1
{\displaystyle P_{1}}
Task details
Use your language's random number generator ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Random_number_generator_(device) | Random number generator (device) | Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| #Sidef | Sidef | func urandom() {
const device = %f'/dev/urandom';
device.open('<:raw', \var fh, \var err) ->
|| die "Can't open `#{device}': #{err}";
fh.sysread(\var noise, 4);
'L'.unpack(noise);
}
say urandom(); # sample: 3517432564 | Give a code snippet in #Sidef
Task
If your system has a means to generate random numbers involving not only a software algorithm (like the /dev/urandom devices in Unix), then:
show how to obtain a random 32-bit number from that mechanism.
Related task
Random_number_generator_(included)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Increment_a_numerical_string | Increment a numerical string | Task
Increment a numerical string.
| #Raku | Raku | my $s = "12345";
$s++; | Give a code snippet in #Raku
Task
Increment a numerical string.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Factors_of_an_integer | Factors of an integer |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #F.23 | F# | let factors number = seq {
for divisor in 1 .. (float >> sqrt >> int) number do
if number % divisor = 0 then
yield divisor
if number <> 1 then yield number / divisor //special case condition: when number=1 then divisor=(number/divisor), so don't repeat it
} | Give a code snippet in #F.23
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
C... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations_with_repetitions | Combinations with repetitions | The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member of those sets is chosen from
S... | #Fortran | Fortran |
program main
integer :: chosen(4)
integer :: ssize
character(len=50) :: donuts(4) = [ "iced", "jam", "plain", "something completely different" ]
ssize = choose( chosen, 2, 3 )
write(*,*) "Total = ", ssize
contains
recursive function choose( got, len, maxTypes, nChosen, at ) result ( output )
integer ... | Give a code snippet in #Fortran
The set of combinations with repetitions is computed from a set,
S
{\displaystyle S}
(of cardinality
n
{\displaystyle n}
), and a size of resulting selection,
k
{\displaystyle k}
, by reporting the sets of cardinality
k
{\displaystyle k}
where each member o... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Julia_set | Julia set |
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| #Lua | Lua | local cmap = { [0]=" ", ".", ":", "-", "=", "+", "*", "#", "%", "$", "@" }
for y = -1.0, 1.0, 0.05 do
for x = -1.5, 1.5, 0.025 do
local zr, zi, i = x, y, 0
while i < 100 do
zr, zi = zr*zr - zi*zi - 0.79, zr * zi * 2 + 0.15
if (zr*zr + zi*zi > 4) then break else i = i + 1 end
end
io.write(c... | Give a code snippet in #Lua
Task
Generate and draw a Julia set.
Related tasks
Mandelbrot Set
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Combinations | Combinations | Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
0 3 4
1 2 3
1 2 4
1 3 4
2 3 4
... | #SETL | SETL | print({0..4} npow 3); | Give a code snippet in #SETL
Task
Given non-negative integers m and n, generate all size m combinations of the integers from 0 (zero) to n-1 in sorted order (each combination is sorted and the entire table is sorted).
Example
3 comb 5 is:
0 1 2
0 1 3
0 1 4
0 2 3
0 2 4
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Nautical_bell | Nautical bell |
Task
Write a small program that emulates a nautical bell producing a ringing bell pattern at certain times throughout the day.
The bell timing should be in accordance with Greenwich Mean Time, unless locale dictates otherwise.
It is permissible for the program to daemonize, or to slave off a scheduler, and it is per... | #Phix | Phix | with javascript_semantics
constant watches = {"First","Middle","Morning","Forenoon","Afternoon","First dog","Last dog","First"},
watch_ends = {"00:00", "04:00", "08:00", "12:00", "16:00", "18:00", "20:00", "23:59"},
bells = {"One","Two","Three","Four","Five","Six","Seven","Eight"},
ding = "di... | Give a code snippet in #Phix
Task
Write a small program that emulates a nautical bell producing a ringing bell pattern at certain times throughout the day.
The bell timing should be in accordance with Greenwich Mean Time, unless locale dictates otherwise.
It is permissible for the program to daemonize, or to slave ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #FreeBASIC | FreeBASIC |
Const alphanum = "0123456789abcdefghijklmnopqrstuvwxyz"
Function ToDecimal (cadena As String, base_ As Uinteger) As Uinteger
Dim As Uinteger i, n, result = 0
Dim As Uinteger inlength = Len(cadena)
For i = 1 To inlength
n = Instr(alphanum, Mid(Lcase(cadena),i,1)) - 1
n *= (base_^(inlen... | Give a code snippet in #FreeBASIC
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 unenco... | christopher/rosetta-code | |
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... | #Objective-C | Objective-C | // Class
[MyClass method:someParameter];
// or equivalently:
id foo = [MyClass class];
[foo method:someParameter];
// Instance
[myInstance method:someParameter];
// Method with multiple arguments
[myInstance methodWithRed:arg1 green:arg2 blue:arg3];
// Method with no arguments
[myInstance method]; | Give a code snippet in #Objective-C
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 stat... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parameterized_SQL_statement | Parameterized SQL statement | SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don't either. | #8th | 8th | \ assuming the var 'db' contains an opened database with a schema matching the problem:
db @
"UPDATE players SET name=?1,score=?2,active=?3 WHERE jerseyNum=?4"
db:prepare var, stmt
\ bind values to the statement:
stmt @ 1 "Smith, Steve" db:bind
2 42 db:bind
3 true db:bind
4 99 db:bind
\ execut... | Give a code snippet in #8th
SQL injection
Using a SQL update statement like this one (spacing is optional):
UPDATE players
SET name = 'Smith, Steve', score = 42, active = TRUE
WHERE jerseyNum = 99
Non-parameterized SQL is the GoTo statement of database programming. Don't do it, and make sure your coworkers don'... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arbitrary-precision_integers_(included) | Arbitrary-precision integers (included) | Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | #PureBasic | PureBasic | IncludeFile "Decimal.pbi"
;- Declare the variables that will be used
Define.Decimal *a
Define n, L$, R$, out$, digits.s
;- 4^3^2 is withing 32 bit range, so normal procedures can be used
n=Pow(4,Pow(3,2))
;- 5^n is larger then 31^2, so the same library call as in the "Long multiplication" task is used
*a=PowerDec... | Give a code snippet in #PureBasic
Using the in-built capabilities of your language, calculate the integer value of:
5
4
3
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Priority_queue | Priority queue | A priority queue is somewhat similar to a queue, with an important distinction: each item is added to a priority queue with a priority level, and will be later removed from the queue with the highest priority element first. That is, the items are (conceptually) stored in the queue in priority order instead of in insert... | #VBScript | VBScript |
option explicit
Class prio_queue
private size
private q
'adapt this function to your data
private function out_of_order(f1,f2): out_of_order = f1(0)>f2(0):end function
function peek
peek=q(1)
end function
property get qty
qty=size
end property
property get isempty
isempty=(size=... | Give a code snippet in #VBScript
A priority queue is somewhat similar to a queue, with an important distinction: each item is added to a priority queue with a priority level, and will be later removed from the queue with the highest priority element first. That is, the items are (conceptually) stored in the queue in p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_element_of_a_list | Greatest element of a list | Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| #Erlang | Erlang | >lists:max([9,4,3,8,5]).
9 | Give a code snippet in #Erlang
Task
Create a function that returns the maximum value in a provided set of values,
where the number of values may not be known until run-time.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #CFScript | CFScript | isNumeric(42) | Give a code snippet in #CFScript
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/ABC_problem | ABC problem | ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is guaranteed amongst all sid... | #C | C | #include <stdio.h>
#include <ctype.h>
int can_make_words(char **b, char *word)
{
int i, ret = 0, c = toupper(*word);
#define SWAP(a, b) if (a != b) { char * tmp = a; a = b; b = tmp; }
if (!c) return 1;
if (!b[0]) return 0;
for (i = 0; b[i] && !ret; i++) {
if (b[i][0] != c && b[i][1] != c) continue;
SWAP... | Give a code snippet in #C
ABC problem
You are encouraged to solve this task according to the task description, using any language you may know.
You are given a collection of ABC blocks (maybe like the ones you had when you were a kid).
There are twenty blocks with two letters on each block.
A complete alphabet is... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Boolean_values | Boolean values | Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| #C.2B.2B | C++ | ::Bool = False | True | Give a code snippet in #C.2B.2B
Task
Show how to represent the boolean states "true" and "false" in a language.
If other objects represent "true" or "false" in conditionals, note it.
Related tasks
Logical operations
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Color_wheel | Color wheel | Task
Write a function to draw a HSV color wheel completely with code.
This is strictly for learning purposes only. It's highly recommended that you use an image in an actual application to actually draw the color wheel (as procedurally drawing is super slow). This does help you understand how color wheels work and ... | #Phix | Phix | --
-- demo\rosetta\Colour_wheel.exw
-- =============================
--
-- Note: Made non-resizeable since maximising this is far too slow.
--
with javascript_semantics
include pGUI.e
constant title = "Colour wheel"
Ihandle dlg, canvas
cdCanvas cddbuffer, cdcanvas
function redraw_cb(Ihandle /*ih*/, integer /*posx*/,... | Give a code snippet in #Phix
Task
Write a function to draw a HSV color wheel completely with code.
This is strictly for learning purposes only. It's highly recommended that you use an image in an actual application to actually draw the color wheel (as procedurally drawing is super slow). This does help you underst... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/While | Loops/While | Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For... | #Icon_and_Unicon | Icon and Unicon | procedure main()
local i
i := 1024
while write(0 < (i := i / 2))
end | Give a code snippet in #Icon_and_Unicon
Task
Start an integer value at 1024.
Loop while it is greater than zero.
Print the value (with a newline) and divide it by two each time through the loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_multiplication | Matrix multiplication | Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| #Amazing_Hopper | Amazing Hopper |
#include <hopper.h>
main:
first matrix=0, second matrix=0,a=-1
{5,2},rand array(a),mulby(10),ceil, cpy(first matrix), puts,{"\n"},puts
{2,3},rand array(a),mulby(10),ceil, cpy(second matrix), puts,{"\n"},puts
{first matrix,second matrix},mat mul, println
exit(0)
| Give a code snippet in #Amazing_Hopper
Task
Multiply two matrices together.
They can be of any dimensions, so long as the number of columns of the first matrix is equal to the number of rows of the second matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Iterated_digits_squaring | Iterated digits squaring | If you add the square of the digits of a Natural number (an integer bigger than zero), you always end with either 1 or 89:
15 -> 26 -> 40 -> 16 -> 37 -> 58 -> 89
7 -> 49 -> 97 -> 130 -> 10 -> 1
An example in Python:
>>> step = lambda x: sum(int(d) ** 2 for d in str(x))
>>> iterate = lambda x: x if x in [1, 89] else i... | #Forth | Forth |
Tested for VFX Forth and GForth in Linux
\ To explain the algorithm: Each iteration is performed in set-count-sumsq below.
\ sum square of digits for 1 digit numbers are
\ Base 1 2 3 4 5 6 7 8 9
\ Sumsq: 1 4 9 16 25 36 49 54 81
\ Adding 10 to the base adds 1 to the sumsq,
\ Adding 20 to the base adds... | Give a code snippet in #Forth
If you add the square of the digits of a Natural number (an integer bigger than zero), you always end with either 1 or 89:
15 -> 26 -> 40 -> 16 -> 37 -> 58 -> 89
7 -> 49 -> 97 -> 130 -> 10 -> 1
An example in Python:
>>> step = lambda x: sum(int(d) ** 2 for d in str(x))
>>> iterate = lam... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Minesweeper_game | Minesweeper game | There is an n by m grid that has a random number (between 10% to 20% of the total number of tiles, though older implementations may use 20%..60% instead) of randomly placed mines that need to be found.
Positions in the grid are modified by entering their coordinates where the first coordinate is horizontal in the grid... | #Haskell | Haskell | {-# LANGUAGE TemplateHaskell #-}
module MineSweeper
( Board
, Cell(..)
, CellState(..)
, Pos
-- lenses / prisms
, pos
, coveredLens
, coveredFlaggedLens
, coveredMinedLens
, xCoordLens
, yCoordLens
-- Functions
, emptyBoard
, groupedByRows
, displayCell
, isLoss
, isWin
, expos... | Give a code snippet in #Haskell
There is an n by m grid that has a random number (between 10% to 20% of the total number of tiles, though older implementations may use 20%..60% instead) of randomly placed mines that need to be found.
Positions in the grid are modified by entering their coordinates where the first coo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Universal_Turing_machine | Universal Turing machine | One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing machine in it.
Task
Simulate such ... | #EchoLisp | EchoLisp |
(require 'struct)
(struct TM (read-only: name states symbs final rules mem state-values: tape pos state))
(define-syntax-rule (rule-idx state symb numstates)
(+ state (* symb numstates)))
(define-syntax-rule (make-TM name states symbs rules)
(_make-TM name 'states 'symbs 'rules))
;; a rule is (stat... | Give a code snippet in #EchoLisp
One of the foundational mathematical constructs behind computer science
is the universal Turing Machine.
(Alan Turing introduced the idea of such a machine in 1936–1937.)
Indeed one way to definitively prove that a language
is turing-complete
is to implement a universal Turing mach... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Bubble_sort | Sorting algorithms/Bubble 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
... | #Gambas | Gambas | Public Sub Main()
Dim byToSort As Byte[] = [249, 28, 111, 36, 171, 98, 29, 448, 44, 147, 154, 46, 102, 183, 24,
120, 19, 123, 2, 17, 226, 11, 211, 25, 191, 205, 77]
Dim byCount As Byte
Dim bSorting As Boolean
Print "To sort: -"
ShowWorking(byToSort)
Print
Repeat
bSorting = False
For byC... | Give a code snippet in #Gambas
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/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #Wren | Wren | var egyptianDivide = Fn.new { |dividend, divisor|
if (dividend < 0 || divisor <= 0) Fiber.abort("Invalid argument(s).")
if (dividend < divisor) return [0, dividend]
var powersOfTwo = [1]
var doublings = [divisor]
var doubling = divisor
while (true) {
doubling = 2 * doubling
if (d... | Give a code snippet in #Wren
Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, an... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Safe_primes_and_unsafe_primes | Safe primes and unsafe primes | Definitions
A safe prime is a prime p and where (p-1)/2 is also prime.
The corresponding prime (p-1)/2 is known as a Sophie Germain prime.
An unsafe prime is a prime p and where (p-1)/2 isn't a prime.
An unsafe prime is a prime that isn't a safe prime.
Task
... | #D | D | import std.stdio;
immutable PRIMES = [
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97,
101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 179, 181, 191, 193, 197, 199,
211, 223, 227, 229, 233, 239, 241, 251, 257, 263, 269, 271, 277, 2... | Give a code snippet in #D
Definitions
A safe prime is a prime p and where (p-1)/2 is also prime.
The corresponding prime (p-1)/2 is known as a Sophie Germain prime.
An unsafe prime is a prime p and where (p-1)/2 isn't a prime.
An unsafe prime is a prime that isn't ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Animation | Animation |
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task demonstrates this.
Task
Creat... | #R | R |
rotate_string <- function(x, forwards)
{
nchx <- nchar(x)
if(forwards)
{
paste(substr(x, nchx, nchx), substr(x, 1, nchx - 1), sep = "")
} else
{
paste(substr(x, 2, nchx), substr(x, 1, 1), sep... | Give a code snippet in #R
Animation is integral to many parts of GUIs, including both the fancy effects when things change used in window managers, and of course games. The core of any animation system is a scheme for periodically changing the display while still remaining responsive to the user. This task demons... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dijkstra%27s_algorithm | Dijkstra's algorithm | This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the single-source shortest path pro... | #Prolog | Prolog | rpath([target|reversed_path], distance) | Give a code snippet in #Prolog
This task has been clarified. Its programming examples are in need of review to ensure that they still fit the requirements of the task.
Dijkstra's algorithm, conceived by Dutch computer scientist Edsger Dijkstra in 1956 and published in 1959, is a graph search algorithm that solves the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pinstripe/Printer | Pinstripe/Printer | The task is to demonstrate the creation of a series of 1 point wide vertical pinstripes with a sufficient number of pinstripes to span the entire width of the printed page (except for the last pinstripe). The pinstripes should alternate one point white, one point black. (Where the printer does not support producing gra... | #Racket | Racket |
#lang racket/gui
(define parts 4)
(define dc (new printer-dc%))
(send* dc (start-doc "Pinstripe") (start-page))
(define-values [W H] (send dc get-size))
(send dc set-pen "black" 0 'solid)
(send dc set-brush "black" 'solid)
(define H* (round (/ H parts)))
(for ([row parts])
(define Y (* row H*))
(for ([X (in... | Give a code snippet in #Racket
The task is to demonstrate the creation of a series of 1 point wide vertical pinstripes with a sufficient number of pinstripes to span the entire width of the printed page (except for the last pinstripe). The pinstripes should alternate one point white, one point black. (Where the printe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Singly-linked_list/Traversal | Singly-linked list/Traversal | Traverse from the beginning of a singly-linked list to the end.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definition, Usage
Set
Singly-linked ... | #Axe | Axe | LINK(L₁,1)→A
LINK(L₁+10,2)→B
LINK(L₁+50,3)→C
INSERT(A,B)
INSERT(A,C)
A→I
While I≠0
Disp VALUE(I)▶Dec,i
NEXT(I)→I
End | Give a code snippet in #Axe
Traverse from the beginning of a singly-linked list to the end.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked list: Definition, Element definition, Element insertion, List Traversal, Element Removal
Linked list
Queue: Definitio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harshad_or_Niven_series | Harshad or Niven series | The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task is to create a function/method/... | #Elixir | Elixir | defmodule Harshad do
def series, do: Stream.iterate(1, &(&1+1)) |> Stream.filter(&(number?(&1)))
def number?(n), do: rem(n, digit_sum(n, 0)) == 0
defp digit_sum(0, sum), do: sum
defp digit_sum(n, sum), do: digit_sum(div(n, 10), sum + rem(n, 10))
end
IO.inspect Harshad.series |> Enum.take(20)
IO.inspect ... | Give a code snippet in #Elixir
The Harshad or Niven numbers are positive integers ≥ 1 that are divisible by the sum of their digits.
For example, 42 is a Harshad number as 42 is divisible by (4 + 2) without remainder.
Assume that the series is defined as the numbers in increasing order.
Task
The task... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Number_reversal_game | Number reversal game | Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The score is the count of the reversa... | #Clojure | Clojure | (defn flip-at [n coll]
(let [[x y] (split-at n coll)]
(concat (reverse x) y )))
(def sorted '(1 2 3 4 5 6 7 8 9)) ; i.e. (range 1 10)
(def unsorted? #(not= % sorted))
(loop [unsorted (first (filter unsorted? (iterate shuffle sorted))), steps 0]
(if (= unsorted sorted)
(printf "Done! That took you %d st... | Give a code snippet in #Clojure
Task
Given a jumbled list of the numbers 1 to 9 that are definitely not in
ascending order.
Show the list, and then ask the player how many digits from the
left to reverse.
Reverse those digits, then ask again, until all the digits end up in ascending order.
The ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Draw_a_cuboid | Draw a cuboid | Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is acceptable for this task.
R... | #Nim | Nim | import strutils
proc cline(n, x, y: int, cde: string) =
echo cde[0..0].align n+1,
repeat(cde[1], 9*x-1),
cde[0],
if cde.len > 2: cde[2..2].align y+1 else: ""
proc cuboid(x, y, z: int) =
cline y+1, x, 0, "+-"
for i in 1..y: cline y-i+1, x, i-1, "/ |"
cline 0, x, y, "+-|"
for i in 0..4*z-y-3: cl... | Give a code snippet in #Nim
Task
Draw a cuboid with relative dimensions of 2 × 3 × 4.
The cuboid can be represented graphically, or in ASCII art, depending on the language capabilities.
To fulfill the criteria of being a cuboid, three faces must be visible.
Either static or rotational projection is a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Probabilistic_choice | Probabilistic choice | Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because floating point arithmetic is invol... | #REXX | REXX | /*REXX program displays results of probabilistic choices, gen random #s per probability.*/
parse arg trials digs seed . /*obtain the optional arguments from CL*/
if trials=='' | trials=="," then trials= +1e6 /*Not specified? Then use the default.*/
if digs=='' | digs=="," then digs= 15 ... | Give a code snippet in #REXX
Given a mapping between items and their required probability of occurrence, generate a million items randomly subject to the given probabilities and compare the target probability of occurrence versus the generated values.
The total of all the probabilities should equal one. (Because floa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rosetta_Code/Find_unimplemented_tasks | Rosetta Code/Find unimplemented tasks | Task
Given the name of a language on Rosetta Code, find all tasks which are not implemented in that language.
Note: Implementations should allow for fetching more data than can be returned in one request to Rosetta Code.
You'll need to use the Media Wiki API, which you can find out about locally, here, or in Media... | #Phix | Phix | -- demo\rosetta\Find_unimplemented_tasks.exw
without js -- (libcurl, file i/o, peek, progress..)
constant language = "Phix",
-- language = "Go",
-- language = "Julia",
-- language = "Python",
-- language = "Wren",
base_query = "http://rosettacode.org/mw/api.php?action=query"&
... | Give a code snippet in #Phix
Task
Given the name of a language on Rosetta Code, find all tasks which are not implemented in that language.
Note: Implementations should allow for fetching more data than can be returned in one request to Rosetta Code.
You'll need to use the Media Wiki API, which you can find out ab... | christopher/rosetta-code | |
http://rosettacode.org/wiki/McNuggets_problem | McNuggets problem | Wikipedia
The McNuggets version of the coin problem was introduced by Henri Picciotto,
who included it in his algebra textbook co-authored with Anita Wah. Picciotto
thought of the application in the 1980s while dining with his son at
McDonald's, working the problem out on a napkin. A McNugget number is
the total number... | #Wren | Wren | var mcnugget = Fn.new { |limit|
var sv = List.filled(limit+1, false)
var s = 0
while (s <= limit) {
var n = s
while (n <= limit) {
var t = n
while (t <= limit) {
sv[t] = true
t = t + 20
}
n = n + 9
}
... | Give a code snippet in #Wren
Wikipedia
The McNuggets version of the coin problem was introduced by Henri Picciotto,
who included it in his algebra textbook co-authored with Anita Wah. Picciotto
thought of the application in the 1980s while dining with his son at
McDonald's, working the problem out on a napkin. A McNug... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorions | Factorions |
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can exceed 1,499,999.
Task
Write a progr... | #F.C5.8Drmul.C3.A6 | Fōrmulæ | Dim As Integer fact(12), suma, d, j
fact(0) = 1
For n As Integer = 1 To 11
fact(n) = fact(n-1) * n
Next n
For b As Integer = 9 To 12
Print "Los factoriones para base " & b & " son: "
For i As Integer = 1 To 1499999
suma = 0
j = i
While j > 0
d = j Mod b
suma +... | Give a code snippet in #F.C5.8Drmul.C3.A6
Definition
A factorion is a natural number that equals the sum of the factorials of its digits.
Example
145 is a factorion in base 10 because:
1! + 4! + 5! = 1 + 24 + 120 = 145
It can be shown (see talk page) that no factorion in base 10 can... | 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
| #E | E | def map(f, list) {
var out := []
for x in list {
out with= f(x)
}
return out
}
? map(fn x { x + x }, [1, "two"])
# value: [2, "twotwo"]
? map(1.add, [5, 10, 20])
# value: [6, 11, 21]
? def foo(x) { return -(x.size()) }
> map(foo, ["", "a", "bc"])
# value: [0, -1, -2] | Give a code snippet in #E
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Circles_of_given_radius_through_two_points | Circles of given radius through two points |
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of circles with the point on thei... | #Wren | Wren | import "/math" for Math
var Two = "Two circles."
var R0 = "R == 0 does not describe circles."
var Co = "Coincident points describe an infinite number of circles."
var CoR0 = "Coincident points with r == 0 describe a degenerate circle."
var Diam = "Points form a diameter and describe only a single circle."
var Fa... | Give a code snippet in #Wren
Given two points on a plane and a radius, usually two circles of given radius can be drawn through the points.
Exceptions
r==0.0 should be treated as never describing circles (except in the case where the points are coincident).
If the points are coincident then an infinite number of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/IBAN | IBAN |
This page uses content from Wikipedia. The original article was at IBAN. 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 International Bank Account Number (IBAN) is an internationally agree... | #Lua | Lua | local length=
{
AL=28, AD=24, AT=20, AZ=28, BH=22, BE=16, BA=20, BR=29, BG=22, CR=21,
HR=21, CY=28, CZ=24, DK=18, DO=28, EE=20, FO=18, FI=18, FR=27, GE=22,
DE=22, GI=23, GR=27, GL=18, GT=28, HU=28, IS=26, IE=22, IL=23, IT=27,
JO=30, KZ=20, KW=30, LV=21, LB=28, LI=21, LT=20, LU=20, MK=19, MT=31,
MR=27, MU=30, ... | Give a code snippet in #Lua
This page uses content from Wikipedia. The original article was at IBAN. 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 International Bank Account Number (IBAN) ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Topic_variable | Topic variable | Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable.
A topic variable is a special variable with a very short name which can also often be omitted.
Demonstrate the utilization and behaviour of the topic variable within the language and explain or demonstrate h... | #BASIC256 | BASIC256 | function Sum (x, y)
Sum = x + y # using name of function
end function
function SumR (x, y)
return x + y # using Return keyword which always returns immediately
end function
print Sum (1, 2)
print SumR(2, 3) | Give a code snippet in #BASIC256
Several programming languages offer syntax shortcuts to deal with the notion of "current" or "topic" variable.
A topic variable is a special variable with a very short name which can also often be omitted.
Demonstrate the utilization and behaviour of the topic variable within the lan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rot-13 | Rot-13 |
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13 encoding of every line of inpu... | #Sidef | Sidef | # Returns a copy of 's' with rot13 encoding.
func rot13(s) {
s.tr('A-Za-z', 'N-ZA-Mn-za-m');
}
# Perform rot13 on standard input.
STDIN.each { |line| print rot13(line) } | Give a code snippet in #Sidef
Task
Implement a rot-13 function (or procedure, class, subroutine, or other "callable" object as appropriate to your programming environment).
Optionally wrap this function in a utility program (like tr, which acts like a common UNIX utility, performing a line-by-line rot-13... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Concurrent_computing | Concurrent computing | Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your language.
| #Cind | Cind |
execute() {
{# host.println("Enjoy");
# host.println("Rosetta");
# host.println("Code"); }
}
| Give a code snippet in #Cind
Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your la... | christopher/rosetta-code | |
http://rosettacode.org/wiki/MAC_Vendor_Lookup | MAC Vendor Lookup | Every connected device around the world comes with a unique Media Access Control address, or a MAC address.
A common task a network administrator may come across is being able to identify a network device's manufacturer when given only a MAC address.
Task
Interface with one (or numerous) APIs that exist on the i... | #Lua | Lua | -- Requires LuaSocket extension by Lua
-- Created by James A. Donnell Jr.
-- www.JamesDonnell.com
local baseURL = "http://api.macvendors.com/"
local function lookup(macAddress)
http = require "socket.http"
result, statuscode, content = http.request(baseURL .. macAddress)
return result
end
local macAddress = "F... | Give a code snippet in #Lua
Every connected device around the world comes with a unique Media Access Control address, or a MAC address.
A common task a network administrator may come across is being able to identify a network device's manufacturer when given only a MAC address.
Task
Interface with one (or numer... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_case | String case | Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not reversable.
Show any additional... | #Tcl | Tcl | set string alphaBETA
# three built-in case conversion commands
string toupper $string ;# ==> ALPHABETA
string tolower $string ;# ==> alphabeta
string totitle $string ;# ==> Alphabeta
# not built-in
proc swapcase {s} {
foreach char [split $s ""] {
if {$char eq [set CHAR [string toupper $char]]} {
... | Give a code snippet in #Tcl
Task
Take the string alphaBETA and demonstrate how to convert it to:
upper-case and
lower-case
Use the default encoding of a string literal or plain ASCII if there is no string literal in your language.
Note: In some languages alphabets toLower and toUpper is not rev... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Concurrent_computing | Concurrent computing | Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your language.
| #Julia | Julia | words = ["Enjoy", "Rosetta", "Code"]
function sleepprint(s)
sleep(rand())
println(s)
end
@sync for word in words
@async sleepprint(word)
end | Give a code snippet in #Julia
Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your l... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Arithmetic_mean | Averages/Arithmetic mean | Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an established convention for conveyin... | #Quackery | Quackery | [ $ 'bigrat.qky' loadfile ] now!
[ [] swap times
[ 20001 random 10000 -
n->v 100 n->v v/
join nested join ] ] is makevector ( --> [ )
[ witheach
[ unpack
2 point$ echo$
i 0 > if
[ say ", " ] ] ] is echodecs ( [ --> )
[ dup size n->v rot... | Give a code snippet in #Quackery
Task[edit]
Write a program to find the mean (arithmetic average) of a numeric vector.
In case of a zero-length input, since the mean of an empty set of numbers is ill-defined, the program may choose to behave in any way it deems appropriate, though if the programming language has an e... | 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.... | #BBC_BASIC | BBC BASIC | DIM x(9), y(9)
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, 149.3, 180.0
ORIGIN 100,100
VDU 23,23,2;0;0;0;
VDU 5
FOR x = 1 TO 9
GCOL 7 : LINE 100*x,720,100*x,0
GCOL 0 : PLOT 0,-10,-4 :... | Give a code snippet in #BBC_BASIC
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, 3... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Snake | Snake |
This page uses content from Wikipedia. The original article was at Snake_(video_game). 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)
Snake is a game where the player maneuvers a line which grows i... | #Raku | Raku | use SDL2::Raw;
use Cairo;
constant W = 1280;
constant H = 960;
constant FIELDW = W div 32;
constant FIELDH = H div 32;
SDL_Init(VIDEO);
my $window = SDL_CreateWindow(
'Snake',
SDL_WINDOWPOS_CENTERED_MASK,
SDL_WINDOWPOS_CENTERED_MASK,
W, H,
OPENGL
);
my $render = SDL_CreateRenderer($window,... | Give a code snippet in #Raku
This page uses content from Wikipedia. The original article was at Snake_(video_game). 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)
Snake is a game where the player ... | christopher/rosetta-code |
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