task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k | response_seed stringclasses 1
value | instruction_seed stringlengths 27 14.4k | _source stringclasses 1
value |
|---|---|---|---|---|---|---|---|---|
http://rosettacode.org/wiki/Jump_anywhere | Jump anywhere | Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom to use these jumps for different... | #Lingo | Lingo | on foo
abort()
end
on bar ()
foo()
put "This will never be printed"
end | Give a code snippet in #Lingo
Imperative programs
conditional structures
loops
local jumps
This task is to demonstrate a local jump and a global jump and the various other types of jumps that the language supports.
For the purpose of this task, the jumps need not be used for a single purpose and you have the freedom t... | 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
| #BaCon | BaCon | other = 42 | Give a code snippet in #BaCon
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/Repeat_a_string | Repeat a string | Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5) => "*****").
Other tasks re... | #Arturo | Arturo | print repeat "ha" 5 | Give a code snippet in #Arturo
Take a string and repeat it some number of times.
Example: repeat("ha", 5) => "hahahahaha"
If there is a simpler/more efficient way to repeat a single “character” (i.e. creating a string filled with a certain character), you might want to show that as well (i.e. repeat-char("*", 5)... | christopher/rosetta-code | |
http://rosettacode.org/wiki/GUI/Maximum_window_dimensions | GUI/Maximum window dimensions | The task is to determine the maximum height and width of a window that can fit within the physical display area of the screen without scrolling.
This is effectively the screen size (not the total desktop area, which could be bigger than the screen display area) in pixels minus any adjustments for window decorations an... | #Julia | Julia |
win = GtkWindow("hello", 100, 100)
fullscreen(win)
sleep(10)
println(width(win), " ", height(win))
destroy(win)
| Give a code snippet in #Julia
The task is to determine the maximum height and width of a window that can fit within the physical display area of the screen without scrolling.
This is effectively the screen size (not the total desktop area, which could be bigger than the screen display area) in pixels minus any adjust... | christopher/rosetta-code | |
http://rosettacode.org/wiki/HTTP | HTTP | Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| #Tcl | Tcl |
package require http
set request [http::geturl "http://www.rosettacode.org"]
puts [http::data $request]
http::cleanup $request | Give a code snippet in #Tcl
Task
Access and print a URL's content (the located resource) to the console.
There is a separate task for HTTPS Requests.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Cantor_set | Cantor set | Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| #Lua | Lua | local WIDTH = 81
local HEIGHT = 5
local lines = {}
function cantor(start, length, index)
-- must be local, or only one side will get calculated
local seg = math.floor(length / 3)
if 0 == seg then
return nil
end
-- remove elements that are not in the set
for it=0, HEIGHT - index do
... | Give a code snippet in #Lua
Task
Draw a Cantor set.
See details at this Wikipedia webpage: Cantor set
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Exceptions | Exceptions | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exceptions Through Nested Calls
| #Prolog | Prolog | foo(X) :-
\+ integer(X),
throw(b('not even an int')).
foo(X) :-
\+ between(1,10,X),
throw(a('must be between 1 & 10')).
foo(X) :-
format('~p is a valid number~n', X).
go(X) :-
catch(
foo(X),
E,
handle(E)).
handle(a(Msg)) :-
format('~w~n', Msg),
!.
handle(X) :-... | Give a code snippet in #Prolog
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
This task is to give an example of an exception handling routine
and to "throw" a new exception.
Related task
Exception... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Parametric_polymorphism | Parametric polymorphism | Parametric Polymorphism
type variables
Task
Write a small example for a type declaration that is parametric over another type, together with a short bit of code (and its type signature) that uses it.
A good example is a container type, let's say a binary tree, together with some function that traverses the tree, ... | #D | D | class ArrayTree(T, uint N) {
T[N] data;
typeof(this) left, right;
this(T initValue) { this.data[] = initValue; }
void tmap(const void delegate(ref typeof(data)) dg) {
dg(this.data);
if (left) left.tmap(dg);
if (right) right.tmap(dg);
}
}
void main() { // Demo code.
... | Give a code snippet in #D
Parametric Polymorphism
type variables
Task
Write a small example for a type declaration that is parametric over another type, together with a short bit of code (and its type signature) that uses it.
A good example is a container type, let's say a binary tree, together with some functio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Almkvist-Giullera_formula_for_pi | Almkvist-Giullera formula for pi | The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10002n+1
This formula can be used to calcul... | #Nim | Nim | import strformat, strutils
import decimal
proc fact(n: int): DecimalType =
result = newDecimal(1)
if n < 2: return
for i in 2..n:
result *= i
proc almkvistGiullera(n: int): DecimalType =
## Return the integer portion of the nth term of Almkvist-Giullera sequence.
let t1 = fact(6 * n) * 32
let t2 = 5... | Give a code snippet in #Nim
The Almkvist-Giullera formula for calculating 1/π2 is based on the Calabi-Yau
differential equations of order 4 and 5, which were originally used to describe certain manifolds
in string theory.
The formula is:
1/π2 = (25/3) ∑0∞ ((6n)! / (n!6))(532n2 + 126n + 9) / 10002n+1
This ... | 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... | #Java | Java |
public class Factorion {
public static void main(String [] args){
System.out.println("Base 9:");
for(int i = 1; i <= 1499999; i++){
String iStri = String.valueOf(i);
int multiplied = operate(iStri,9);
if(multiplied == i){
System.out.print(i + "\t... | Give a code snippet in #Java
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 1,4... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Multiplication_tables | Multiplication tables | Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| #Common_Lisp | Common Lisp |
(do ((m 0 (if (= 12 m) 0 (1+ m)))
(n 0 (if (= 12 m) (1+ n) n)))
((= n 13))
(if (zerop n)
(case m
(0 (format t " *|"))
(12 (format t " 12~&---+------------------------------------------------~&"))
(otherwise
(format t "~4,D" m)))
(case m
(0 (format t "~... | Give a code snippet in #Common_Lisp
Task
Produce a formatted 12×12 multiplication table of the kind memorized by rote when in primary (or elementary) school.
Only print the top half triangle of products.
| 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
... | #Futhark | Futhark |
fun main(s: []i32) = s[::-1]
| Give a code snippet in #Futhark
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/Animate_a_pendulum | Animate a pendulum |
One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display.
The classic such physical system is a simple gravity pendulum.
Task
Create a simple physical model of a pendulum and animate it.
| #Liberty_BASIC | Liberty BASIC | nomainwin
WindowWidth = 400
WindowHeight = 300
open "Pendulum" for graphics_nsb_nf as #main
#main "down;fill white; flush"
#main "color black"
#main "trapclose [quit.main]"
Angle = asn(1)
DeltaT = 0.1
PendLength = 150
FixX = int(WindowWidth / 2)
FixY = 40
timer 30, ... | Give a code snippet in #Liberty_BASIC
One good way of making an animation is by simulating a physical system and illustrating the variables in that system using a dynamically changing graphical display.
The classic such physical system is a simple gravity pendulum.
Task
Create a simple physical model of a pendul... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Text | Hello world/Text | Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
Hello world/Web server
| #EGL | EGL |
program HelloWorld
function main()
SysLib.writeStdout("Hello world!");
end
end
| Give a code snippet in #EGL
Hello world/Text is part of Short Circuit's Console Program Basics selection.
Task
Display the string Hello world! on a text console.
Related tasks
Hello world/Graphical
Hello world/Line Printer
Hello world/Newbie
Hello world/Newline omission
Hello world/Standard error
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Day_of_the_week | Day of the week | A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what years between 2008 and 2121 will the 25th of ... | #Component_Pascal | Component Pascal |
MODULE DayOfWeek;
IMPORT DevCommanders, TextMappers, Dates, StdLog;
PROCEDURE XmastOnSun(s,e: INTEGER);
VAR
i: INTEGER;
d: Dates.Date;
BEGIN
i := s;d.day := 25;d.month := 12;
WHILE i < e DO
d.year := i;
IF Dates.DayOfWeek(d) = Dates.sunday THEN
StdLog.Int(i);StdLog.Ln
END;
INC(i)
END
END XmastOnSun;... | Give a code snippet in #Component_Pascal
A company decides that whenever Xmas falls on a Sunday they will give their workers all extra paid holidays so that, together with any public holidays, workers will not have to work the following week (between the 25th of December and the first of January).
Task
In what yea... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Run-length_encoding | Run-length encoding | Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a function to reverse the compression... | #PARI.2FGP | PARI/GP | rle(s)={
if(s=="", return(s));
my(v=Vec(s),cur=v[1],ct=1,out="");
v=concat(v,99); \\ sentinel
for(i=2,#v,
if(v[i]==cur,
ct++
,
out=Str(out,ct,cur);
cur=v[i];
ct=1
)
);
out
};
elr(s)={
if(s=="", return(s));
my(v=Vec(s),ct=eval(v[1]),out="");
v=concat(v,99); \\ sentin... | Give a code snippet in #PARI.2FGP
Run-length encoding
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Given a string containing uppercase characters (A-Z), compress repeated 'runs' of the same character by storing the length of that run, and provide a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/AKS_test_for_primes | AKS test for primes | The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the coefficients of the polynomial ... | #Kotlin | Kotlin | // version 1.1
fun binomial(n: Int, k: Int): Long = when {
n < 0 || k < 0 -> throw IllegalArgumentException("negative numbers not allowed")
k == 0 -> 1L
k == n -> 1L
else -> {
var prod = 1L
var div = 1L
for (i in 1..k) {
prod *= (n + 1 - i... | Give a code snippet in #Kotlin
The AKS algorithm for testing whether a number is prime is a polynomial-time algorithm based on an elementary theorem about Pascal triangles.
The theorem on which the test is based can be stated as follows:
a number
p
{\displaystyle p}
is prime if and only if all the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numerical_integration | Numerical integration | Write functions to calculate the definite integral of a function ƒ(x) using all five of the following methods:
rectangular
left
right
midpoint
trapezium
Simpson's
composite
Your functions should take in the upper and lower bounds (a and b), and the number of approximations to make in that range (n).
Assume t... | #Elixir | Elixir | defmodule Numerical do
@funs ~w(leftrect midrect rightrect trapezium simpson)a
def leftrect(f, left,_right), do: f.(left)
def midrect(f, left, right), do: f.((left+right)/2)
def rightrect(f,_left, right), do: f.(right)
def trapezium(f, left, right), do: (f.(left)+f.(right))/2
def simpson(f, left, ri... | Give a code snippet in #Elixir
Write functions to calculate the definite integral of a function ƒ(x) using all five of the following methods:
rectangular
left
right
midpoint
trapezium
Simpson's
composite
Your functions should take in the upper and lower bounds (a and b), and the number of approximations to m... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Even_or_odd | Even or odd | Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divide i by 2. The remainder equals... | #Sidef | Sidef | var n = 42;
say n.is_odd; # false
say n.is_even; # true | Give a code snippet in #Sidef
Task
Test whether an integer is even or odd.
There is more than one way to solve this task:
Use the even and odd predicates, if the language provides them.
Check the least significant digit. With binary integers, i bitwise-and 1 equals 0 iff i is even, or equals 1 iff i is odd.
Divi... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutations | Permutations | Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations generation tasks.
Order Uni... | #Pascal | Pascal | program perm;
var
p: array[1 .. 12] of integer;
is_last: boolean;
n: integer;
procedure next;
var i, j, k, t: integer;
begin
is_last := true;
i := n - 1;
while i > 0 do
begin
if p[i] < p[i + 1] then
begin
is_last := false;
break;
end;
i := i - 1;
end;
if not is_last then
begin
j := i + 1;
k := n... | Give a code snippet in #Pascal
Task
Write a program that generates all permutations of n different objects. (Practically numerals!)
Related tasks
Find the missing permutation
Permutations/Derangements
The number of samples of size k from n objects.
With combinations and permutations gen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Factorial | Factorial | Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a number.
Solutions can be iterat... | #Rapira | Rapira | Фун Факт(n)
f := 1
для i от 1 до n
f := f * i
кц
Возврат f
Кон Фун | Give a code snippet in #Rapira
Definitions
The factorial of 0 (zero) is defined as being 1 (unity).
The Factorial Function of a positive integer, n, is defined as the product of the sequence:
n, n-1, n-2, ... 1
Task
Write a function to return the factorial of a ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Zumkeller_numbers | Zumkeller numbers | Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divisors are partitioned, only that ... | #Sidef | Sidef | func is_Zumkeller(n) {
return false if n.is_prime
return false if n.is_square
var sigma = n.sigma
# n must have an even abundance
return false if (sigma.is_odd || (sigma < 2*n))
# true if n is odd and has an even abundance
return true if n.is_odd # conjecture
var divisors = ... | Give a code snippet in #Sidef
Zumkeller numbers are the set of numbers whose divisors can be partitioned into two disjoint sets that sum to the same value. Each sum must contain divisor values that are not in the other sum, and all of the divisors must be in one or the other. There are no restrictions on how the divis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Square_but_not_cube | Square but not cube | Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| #Sidef | Sidef | var square_and_cube = Enumerator({|f|
1..Inf -> each {|n| f(n**6) }
})
var square_but_not_cube = Enumerator({|f|
1..Inf -> lazy.map {|n| n**2 }.grep {|n| !n.is_power(3) }.each {|n| f(n) }
})
say "First 30 positive integers that are a square but not a cube:"
say square_but_not_cube.first(30).join(' ')
say ... | Give a code snippet in #Sidef
Task
Show the first 30 positive integers which are squares but not cubes of such integers.
Optionally, show also the first 3 positive integers which are both squares and cubes, and mark them as such.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Generate_lower_case_ASCII_alphabet | Generate lower case ASCII alphabet | Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a reliable style of coding, a sty... | #D | D | import std.ascii: lowercase;
void main() {} | Give a code snippet in #D
Task
Generate an array, list, lazy sequence, or even an indexable string of all the lower case ASCII characters, from a to z. If the standard library contains such a sequence, show how to access it, but don't fail to show how to generate a similar sequence.
For this basic task use a reli... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Integer_comparison | Integer comparison |
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 |... | #Ring | Ring |
Func Compare a,b
if a < b
See "A is less than B"
but a > b
See "A is more than B"
else
See "A equals B"
ok
| Give a code snippet in #Ring
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/Enumerations | Enumerations | Task
Create an enumeration of constants with and without explicit values.
| #AutoHotkey | AutoHotkey | fruit_%apple% = 0
fruit_%banana% = 1
fruit_%cherry% = 2 | Give a code snippet in #AutoHotkey
Task
Create an enumeration of constants with and without explicit values.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Permutation_test | Permutation test | Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a group of
n
{\displaystyle n}
treatment... | #J | J | require'stats'
trmt=: 0.85 0.88 0.75 0.66 0.25 0.29 0.83 0.39 0.97
ctrl=: 0.68 0.41 0.1 0.49 0.16 0.65 0.32 0.92 0.28 0.98
difm=: -&mean
result=: trmt difm ctrl
all=: trmt(#@[ ({. difm }.) |:@([ (comb ~.@,"1 i.@])&# ,) { ,) ctrl
smoutput 'under: ','%',~":100*mean all <: result
smoutput 'over: ','%',~":100*mean all > r... | Give a code snippet in #J
Permutation test
You are encouraged to solve this task according to the task description, using any language you may know.
A new medical treatment was tested on a population of
n
+
m
{\displaystyle n+m}
volunteers, with each volunteer randomly assigned either to a group of
n
{\... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-1 | SHA-1 | SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to identify commits.
A US government... | #Halon | Halon | $var = "Rosetta Code";
echo sha1($var); | Give a code snippet in #Halon
SHA-1 or SHA1 is a one-way hash function;
it computes a 160-bit message digest.
SHA-1 often appears in security protocols; for example,
many HTTPS websites use RSA with SHA-1 to secure their connections.
BitTorrent uses SHA-1 to verify downloads.
Git and Mercurial use SHA-1 digests to ide... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sort_an_integer_array | Sort an integer array |
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
... | #Sidef | Sidef | var nums = [2,4,3,1,2];
var sorted = nums.sort; # returns a new sorted array.
nums.sort!; # sort 'nums' "in-place" | Give a code snippet in #Sidef
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick so... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_a_file_line_by_line | Read a file line by line | Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| #Vala | Vala |
public static void main(){
var file = FileStream.open("foo.txt", "r");
string line = file.read_line();
while (line != null){
stdout.printf("%s\n", line);
line = file.read_line();
}
}
| Give a code snippet in #Vala
Read a file one line at a time,
as opposed to reading the entire file at once.
Related tasks
Read a file character by character
Input loop.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #Jsish | Jsish | /* SHA-256 hash in Jsish */
var str = 'Rosetta code';
puts(Util.hash(str, {type:'sha256'}));
/*
=!EXPECTSTART!=
764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
=!EXPECTEND!=
*/ | Give a code snippet in #Jsish
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b78... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Soundex | Soundex | Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is a major issue in many of the ... | #C.2B.2B | C++ |
#include <iostream> // required for debug code in main() only
#include <iomanip> // required for debug code in main() only
#include <string>
std::string soundex( char const* s )
{
static char const code[] = { 0, -1, 1, 2, 3, -1, 1, 2, 0, -1, 2, 2, 4, 5, 5, -1, 1, 2, 6, 2, 3, -1, 1, 0, 2, 0,... | Give a code snippet in #C.2B.2B
Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Smith_numbers | Smith numbers | Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are also known as joke numbers.... | #Stata | Stata | function factor(_n) {
n = _n
a = J(14, 2, .)
i = 0
if (mod(n, 2)==0) {
j = 0
while (mod(n, 2)==0) {
j++
n = n/2
}
i++
a[i,1] = 2
a[i,2] = j
}
for (k=3; k*k<=n; k=k+2) {
if (mod(n, k)==0) {
j = 0
while (mod(n, k)==0) {
j++
n = n/k
}
i++
a[i,1] = k
a[i,2] = j
}
}
if... | Give a code snippet in #Stata
Smith numbers are numbers such that the sum of the decimal digits of the integers that make up that number is the same as the sum of the decimal digits of its prime factors excluding 1.
By definition, all primes are excluded as they (naturally) satisfy this condition!
Smith numbers are ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_palindromic_numbers_in_both_binary_and_ternary_bases | Find palindromic numbers in both binary and ternary bases | Find palindromic numbers in both binary and ternary bases
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both:
base 2
base 3
Display 0 ... | #J | J | isPalin=: -: |. NB. check if palindrome
toBase=: #.inv"0 NB. convert to base(s) in left arg
filterPalinBase=: ] #~ isPalin@toBase/ NB. palindromes for base(s)
find23Palindromes=: 3 filterPalinBase 2 filterPalinBase ] NB. palindromes in both base 2 and base 3
showBas... | Give a code snippet in #J
Find palindromic numbers in both binary and ternary bases
You are encouraged to solve this task according to the task description, using any language you may know.
Task
Find and show (in decimal) the first six numbers (non-negative integers) that are palindromes in both:
base 2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sum_and_product_of_an_array | Sum and product of an array | Task
Compute the sum and product of an array of integers.
| #E | E | pragma.enable("accumulator")
accum 0 for x in [1,2,3,4,5] { _ + x }
accum 1 for x in [1,2,3,4,5] { _ * x } | Give a code snippet in #E
Task
Compute the sum and product of an array of integers.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Create_a_two-dimensional_array_at_runtime | Create a two-dimensional array at runtime |
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numbers, and which can be accessed ... | #Clean | Clean | import StdEnv
Start :: *World -> { {Real} }
Start world
# (console, world) = stdio world
(_, dim1, console) = freadi console
(_, dim2, console) = freadi console
= createArray dim1 (createArray dim2 1.0) | Give a code snippet in #Clean
Data Structure
This illustrates a data structure, a means of storing data within a program.
You may see other such structures in the Data Structures category.
Get two integers from the user, then create a two-dimensional array where the two dimensions have the sizes given by those numb... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Hello_world/Newbie | Hello world/Newbie | Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the language-newbie is competent in install... | #C.2B.2B | C++ | #include <iostream>
int main() {
using namespace std;
cout << "Hello, World!" << endl;
return 0;
} | Give a code snippet in #C.2B.2B
Task
Guide a new user of a language through the steps necessary
to install the programming language and selection of a text editor if needed,
to run the languages' example in the Hello world/Text task.
Assume the language-newbie is a programmer in another language.
Assume the langua... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Secure_temporary_file | Secure temporary file | Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" criteria).
The function shou... | #Tcl | Tcl | set chan [file tempfile filenameVar] | Give a code snippet in #Tcl
Task
Create a temporary file, securely and exclusively (opening it such that there are no possible race conditions).
It's fine assuming local filesystem semantics (NFS or other networking filesystems can have signficantly more complicated semantics for satisfying the "no race conditions" ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_HQ9%2B | Execute HQ9+ | Task
Implement a HQ9+ interpreter or compiler.
| #Raku | Raku | class HQ9Interpreter {
has @!code;
has $!accumulator;
has $!pointer;
method run ($code) {
@!code = $code.comb;
$!accumulator = 0;
$!pointer = 0;
while $!pointer < @!code {
given @!code[$!pointer].lc {
when 'h' { say 'Hello world!' }
... | Give a code snippet in #Raku
Task
Implement a HQ9+ interpreter or compiler.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Inheritance/Single | Inheritance/Single | This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent types.
Usually inherited properties... | #BBC_BASIC | BBC BASIC | INSTALL @lib$+"CLASSLIB"
DIM Animal{method}
PROC_class(Animal{})
DIM Cat{method}
PROC_inherit(Cat{}, Animal{})
PROC_class(Cat{})
DIM Dog{method}
PROC_inherit(Dog{}, Animal{})
PROC_class(Dog{})
DIM Labrador{method}
PROC_inherit(Labrador{}, Dog{})
... | Give a code snippet in #BBC_BASIC
This task is about derived types; for implementation inheritance, see Polymorphism.
Inheritance is an operation of type algebra that creates a new type from one or several parent types.
The obtained type is called derived type.
It inherits some of the properties of its parent t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Calendar | Calendar | Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with accented characters). Target fo... | #Huginn | Huginn | import DateTime as dt;
import Algorithms as algo;
import Text as text;
class Calendar {
_monthNames_ = none;
_dayNames_ = none;
constructor() {
t = dt.now();
_monthNames_ = algo.materialize( algo.map( algo.range( 1, 13 ), @[t]( m ) { dt.format( "%B", t.set_date( 1, m, 1 ) ); } ), tuple );
_dayNames_... | Give a code snippet in #Huginn
Create a routine that will generate a text calendar for any year.
Test the calendar by generating a calendar for the year 1969, on a device of the time.
Choose one of the following devices:
A line printer with a width of 132 characters.
An IBM 3278 model 4 terminal (80×43 display with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Attractive_numbers | Attractive numbers | A number is an attractive number if the number of its prime factors (whether distinct or not) is also prime.
Example
The number 20, whose prime decomposition is 2 × 2 × 5, is an attractive number because the number of its prime factors (3) is also prime.
Task
Show sequence items up to 120.... | #Raku | Raku | use Lingua::EN::Numbers;
use ntheory:from<Perl5> <factor is_prime>;
sub display ($n,$m) { ($n..$m).grep: (~*).&factor.elems.&is_prime }
sub count ($n,$m) { +($n..$m).grep: (~*).&factor.elems.&is_prime }
# The Task
put "Attractive numbers from 1 to 120:\n" ~
display(1, 120)».fmt("%3d").rotor(20, :partial).join: "\... | Give a code snippet in #Raku
A number is an attractive number if the number of its prime factors (whether distinct or not) is also prime.
Example
The number 20, whose prime decomposition is 2 × 2 × 5, is an attractive number because the number of its prime factors (3) is also prime.
Task
Sh... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #Delphi | Delphi | program LoopWithStep;
{$APPTYPE CONSOLE}
var
i: Integer;
begin
i:=2;
while i <= 8 do begin
WriteLn(i);
Inc(i, 2);
end;
end. | Give a code snippet in #Delphi
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/In... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Top_rank_per_group | Top rank per group | Task
Find the top N salaries in each department, where N is provided as a parameter.
Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source:
Employee Name,Employee ID,Salary,Department
Tyler Bennett... | #Julia | Julia | # v0.6.0
using DataFrames
df = DataFrame(
EmployeeName=["Tyler Bennett", "John Rappl", "George Woltman", "Adam Smith",
"Claire Buckman", "David McClellan", "Rich Holcomb", "Nathan Adams",
"Richard Potter", "David Motsinger", "Tim Sampair", "Kim Arlich", "Timothy Grove"],
EmployeeID = ["E10297", "E21437", "E00127", ... | Give a code snippet in #Julia
Task
Find the top N salaries in each department, where N is provided as a parameter.
Use this data as a formatted internal data structure (adapt it to your language-native idioms, rather than parse at runtime), or identify your external data source:
Employee Name,Employee ID,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Character_codes | Character codes |
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conversely, given a code, print out... | #Lasso | Lasso | 'a'->integer
'A'->integer
97->bytes
65->bytes | Give a code snippet in #Lasso
Task
Given a character value in your language, print its code (could be ASCII code, Unicode code, or whatever your language uses).
Example
The character 'a' (lowercase letter A) has a code of 97 in ASCII (as well as Unicode, as ASCII forms the beginning of Unicode).
Conv... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Langton%27s_ant | Langton's ant | Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the following rules:
If the ce... | #Ruby | Ruby | class Ant
class OutOfBoundsException < StandardError; end
class Plane
def initialize(x, y)
@size_x, @size_y = x, y
@cells = Array.new(y) {Array.new(x, :white)}
end
def white?(px, py)
@cells[py][px] == :white
end
def toggle_colour(px, py)
@cells[py][px] = (white?(p... | Give a code snippet in #Ruby
Langton's ant is a cellular automaton that models an ant sitting on a plane of cells, all of which are white initially, the ant facing in one of four directions.
Each cell can either be black or white.
The ant moves according to the color of the cell it is currently sitting in, with the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Towers_of_Hanoi | Towers of Hanoi | Task
Solve the Towers of Hanoi problem with recursion.
| #Forth | Forth | CREATE peg1 ," left "
CREATE peg2 ," middle "
CREATE peg3 ," right "
: .$ COUNT TYPE ;
: MOVE-DISK
LOCALS| via to from n |
n 1 =
IF CR ." Move disk from " from .$ ." to " to .$
ELSE n 1- from via to RECURSE
1 from to via RECURSE
n 1- via to from RECURSE
THEN ; | Give a code snippet in #Forth
Task
Solve the Towers of Hanoi problem with recursion.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Quine | Quine | A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer program
self-reproducing program ... | #BBC_BASIC | BBC BASIC | PRINT $(PAGE+22)$(PAGE+21):REM PRINT $(PAGE+22)$(PAGE+21):REM | Give a code snippet in #BBC_BASIC
A quine is a self-referential program that can,
without any external access, output its own source.
A quine (named after Willard Van Orman Quine) is also known as:
self-reproducing automata (1972)
self-replicating program or self-replicating computer progra... | christopher/rosetta-code | |
http://rosettacode.org/wiki/One-dimensional_cellular_automata | One-dimensional cellular automata | Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current generation.
If, in the follow... | #Rust | Rust | fn get_new_state(windowed: &[bool]) -> bool {
match windowed {
[false, true, true] | [true, true, false] => true,
_ => false
}
}
fn next_gen(cell: &mut [bool]) {
let mut v = Vec::with_capacity(cell.len());
v.push(cell[0]);
for i in cell.windows(3) {
v.push(get_new_state(i))... | Give a code snippet in #Rust
Assume an array of cells with an initial distribution of live and dead cells,
and imaginary cells off the end of the array having fixed values.
Cells in the next generation of the array are calculated based on the value of the cell and its left and right nearest neighbours in the current ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Substring | Substring |
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 |... | #Clojure | Clojure |
(def string "alphabet")
(def n 2)
(def m 4)
(def len (count string))
;starting from n characters in and of m length;
(println
(subs string n (+ n m))) ;phab
;starting from n characters in, up to the end of the string;
(println
(subs string n)) ;phabet
;whole string minus last c... | Give a code snippet in #Clojure
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/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... | #AWK | AWK | #!/usr/bin/awk -f
# tested with mawk 1.3.3 on Raspberry Pi 3
# also GNU awk 3.1.5, busybox 1.21.1 and 1.27.1 on AMD Sempron 2800+
#
function setblocks() {
# key to the algorithm is the representation of a block
# each block is represented by 4 characters in the string "blocks"
# for example, the "BO" block becom... | Give a code snippet in #AWK
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/99_bottles_of_beer | 99 bottles of beer | Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98 bottles of beer
Take one dow... | #Jsish | Jsish | /* 99 Bottles, in Jsish */
function plural(n:number):string { return (bottles == 1) ? "" : "s"; }
function no(n:number):string { return (bottles == 0) ? "No" : n.toString(); }
var bottles = 99;
do {
printf("%d bottle%s of beer on the wall\n", bottles, plural(bottles));
printf("%d bottle%s of beer\n", bottles,... | Give a code snippet in #Jsish
Task
Display the complete lyrics for the song: 99 Bottles of Beer on the Wall.
The beer song
The lyrics follow this form:
99 bottles of beer on the wall
99 bottles of beer
Take one down, pass it around
98 bottles of beer on the wall
98 bottles of beer on the wall
98... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Abundant,_deficient_and_perfect_number_classifications | Abundant, deficient and perfect number classifications | These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient (OEIS A005100).
if P(n)... | #Phix | Phix | integer deficient=0, perfect=0, abundant=0, N
for i=1 to 20000 do
N = sum(factors(i))+(i!=1)
if N=i then
perfect += 1
elsif N<i then
deficient += 1
else
abundant += 1
end if
end for
printf(1,"deficient:%d, perfect:%d, abundant:%d\n",{deficient, perfect, abundant})
| Give a code snippet in #Phix
These define three classifications of positive integers based on their proper divisors.
Let P(n) be the sum of the proper divisors of n where the proper divisors are all positive divisors of n other than n itself.
if P(n) < n then n is classed as deficient ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Associative_array/Iteration | Associative array/Iteration | Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Compound data type
Doubly-linked ... | #Lasso | Lasso |
//iterate over associative array
//Lasso maps
local('aMap' = map('weight' = 112,
'height' = 45,
'name' = 'jason'))
' Map output: \n '
#aMap->forEachPair => {^
//display pair, then show accessing key and value individually
#1+'\n '
#1->first+': '+#1->second+'\n '
^}
//display keys and values s... | Give a code snippet in #Lasso
Show how to iterate over the key-value pairs of an associative array, and print each pair out.
Also show how to iterate just over the keys, or the values, if there is a separate way to do that in your language.
See also
Array
Associative array: Creation, Iteration
Collections
Com... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Chinese_remainder_theorem | Chinese remainder theorem | Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\displaystyle a_{1}}
,
a
2
... | #Coffeescript | Coffeescript | crt = (n,a) ->
sum = 0
prod = n.reduce (a,c) -> a*c
for [ni,ai] in _.zip n,a
p = prod // ni
sum += ai * p * mulInv p,ni
sum % prod
mulInv = (a,b) ->
b0 = b
[x0,x1] = [0,1]
if b==1 then return 1
while a > 1
q = a // b
[a,b] = [b, a % b]
[x0,x1] = [x1-q*x0, x0]
if x1 < 0 then x1 += b0
x1
print crt... | Give a code snippet in #Coffeescript
Suppose
n
1
{\displaystyle n_{1}}
,
n
2
{\displaystyle n_{2}}
,
…
{\displaystyle \ldots }
,
n
k
{\displaystyle n_{k}}
are positive integers that are pairwise co-prime.
Then, for any given sequence of integers
a
1
{\d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Huffman_coding | Huffman coding | Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols.
For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you could just encode each letter wi... | #Kotlin | Kotlin | import java.util.*
abstract class HuffmanTree(var freq: Int) : Comparable<HuffmanTree> {
override fun compareTo(other: HuffmanTree) = freq - other.freq
}
class HuffmanLeaf(freq: Int, var value: Char) : HuffmanTree(freq)
class HuffmanNode(var left: HuffmanTree, var right: HuffmanTree) : HuffmanTree(left.freq +... | Give a code snippet in #Kotlin
Huffman encoding is a way to assign binary codes to symbols that reduces the overall number of bits used to encode a typical string of those symbols.
For example, if you use letters as symbols and have details of the frequency of occurrence of those letters in typical strings, then you ... | 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.
| #Delphi | Delphi | program ConcurrentComputing;
{$APPTYPE CONSOLE}
uses SysUtils, Classes, Windows;
type
TRandomThread = class(TThread)
private
FString: string;
protected
procedure Execute; override;
public
constructor Create(const aString: string); overload;
end;
constructor TRandomThread.Create(const aStri... | Give a code snippet in #Delphi
Task
Using either native language concurrency syntax or freely available libraries, write a program to display the strings "Enjoy" "Rosetta" "Code", one string per line, in random order.
Concurrency syntax must use threads, tasks, co-routines, or whatever concurrency is called in your ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Metaprogramming | Metaprogramming | Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation.
For the purposes of this task, "support for metaprogramming" means any way the user can effect... | #Tcl | Tcl | proc loopVar {var from lower to upper script} {
if {$from ne "from" || $to ne "to"} {error "syntax error"}
upvar 1 $var v
if {$lower <= $upper} {
for {set v $lower} {$v <= $upper} {incr v} {
uplevel 1 $script
}
} else {
# $upper and $lower really the other way round h... | Give a code snippet in #Tcl
Name and briefly demonstrate any support your language has for metaprogramming. Your demonstration may take the form of cross-references to other tasks on Rosetta Code. When possible, provide links to relevant documentation.
For the purposes of this task, "support for metaprogramming" mean... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vogel%27s_approximation_method | Vogel's approximation method | Vogel's Approximation Method (VAM) is a technique for finding a good initial feasible solution to an allocation problem.
The powers that be have identified 5 tasks that need to be solved urgently. Being imaginative chaps, they have called them “A”, “B”, “C”, “D”, and “E”. They estimate that:
A will require 30 hours ... | #Perl | Perl | #!/usr/bin/perl
use strict; # https://rosettacode.org/wiki/Vogel%27s_approximation_method
use warnings;
use List::AllUtils qw( max_by nsort_by min );
my $data = <<END;
A=30 B=20 C=70 D=30 E=60
W=50 X=60 Y=50 Z=50
AW=16 BW=16 CW=13 DW=22 EW=17
AX=14 BX=14 CX=13 DX=19 EX=15
AY=19 BY=19 CY=20 DY=23 EY=50
AZ=50 BZ=12 C... | Give a code snippet in #Perl
Vogel's Approximation Method (VAM) is a technique for finding a good initial feasible solution to an allocation problem.
The powers that be have identified 5 tasks that need to be solved urgently. Being imaginative chaps, they have called them “A”, “B”, “C”, “D”, and “E”. They estimate th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Euler_method | Euler method | Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
d
y
(
t
)
d
t
=
f... | #Raku | Raku | sub euler ( &f, $y0, $a, $b, $h ) {
my $y = $y0;
my @t_y;
for $a, * + $h ... * > $b -> $t {
@t_y[$t] = $y;
$y += $h * f( $t, $y );
}
return @t_y;
}
constant COOLING_RATE = 0.07;
constant AMBIENT_TEMP = 20;
constant INITIAL_TEMP = 100;
constant INITIAL_TIME = 0;
constant FINAL... | Give a code snippet in #Raku
Euler's method numerically approximates solutions of first-order ordinary differential equations (ODEs) with a given initial value. It is an explicit method for solving initial value problems (IVPs), as described in the wikipedia page.
The ODE has to be provided in the following form:
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variadic_function | Variadic function | Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
Related task
Call a function... | #Sidef | Sidef | func print_all(*things) {
things.each { |x| say x };
} | Give a code snippet in #Sidef
Task
Create a function which takes in a variable number of arguments and prints each one on its own line.
Also show, if possible in your language, how to call the function on a list of arguments constructed at runtime.
Functions of this type are also known as Variadic Functions.
R... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mean_angle | Averages/Mean angle | When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle.
If one wanted an average direction of the wind over two readings where the first reading was of 350 degrees and the ... | #PureBasic | PureBasic | NewList angle.d()
Macro AE(x)
AddElement(angle()) : angle()=x
EndMacro
Procedure.d atan3(y.d,x.d)
If x<=0.0 : ProcedureReturn Sign(y)*#PI/2 : EndIf
If x>0.0 : ProcedureReturn ATan(y/x) : EndIf
If y>0.0 : ProcedureReturn ATan(y/x)+#PI : EndIf
ProcedureReturn ATan(y/x)-#PI
EndProcedure
Procedure.d m... | Give a code snippet in #PureBasic
When calculating the average or mean of an angle one has to take into account how angles wrap around so that any angle in degrees plus any integer multiple of 360 degrees is a measure of the same angle.
If one wanted an average direction of the wind over two readings where the first ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Price_fraction | Price fraction | A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and 1.00, rescale according to ... | #BASIC | BASIC | DECLARE FUNCTION PriceFraction! (price AS SINGLE)
RANDOMIZE TIMER
DIM x AS SINGLE
x = RND
PRINT x, PriceFraction(x)
FUNCTION PriceFraction! (price AS SINGLE)
'returns price unchanged if invalid value
SELECT CASE price
CASE IS < 0!
PriceFraction! = price
CASE IS < .06
... | Give a code snippet in #BASIC
A friend of mine runs a pharmacy. He has a specialized function in his Dispensary application which receives a decimal value of currency and replaces it to a standard value. This value is regulated by a government department.
Task
Given a floating point value between 0.00 and ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Infinity | Infinity | Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise, return the largest possible po... | #Factor | Factor | 1/0. | Give a code snippet in #Factor
Task
Write a function which tests if infinity is supported for floating point numbers (this step should be omitted for languages where the language specification already demands the existence of infinity, e.g. by demanding IEEE numbers), and if so, returns positive infinity. Otherwise... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Infinite | Loops/Infinite | Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within l... | #Tailspin | Tailspin |
1 -> \(
<> 'SPAM$#10;' -> !OUT::write
1 -> #
\) -> !VOID
| Give a code snippet in #Tailspin
Task
Print out SPAM followed by a newline in an infinite loop.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
L... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Quicksort | Sorting algorithms/Quicksort |
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
... | #Visual_Basic | Visual Basic | Sub QuickSort(arr() As Integer, ByVal f As Integer, ByVal l As Integer)
i = f 'First
j = l 'Last
Key = arr(i) 'Pivot
Do While i < j
Do While i < j And Key < arr(j)
j = j - 1
Loop
If i < j Then arr(i) = arr(j): i = i + 1
Do While i < j And Key > arr(i)
... | Give a code snippet in #Visual_Basic
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 |
Q... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Box_the_compass | Box the compass | There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print and display a table of Index, Compass... | #Euphoria | Euphoria | constant names = {"North","North by east","North-northeast","Northeast by north",
"Northeast","Northeast by east","East-northeast","East by north","East",
"East by south","East-southeast","Southeast by east","Southeast","Southeast by south",
"South-southeast","South by east","South","South by west","South-s... | Give a code snippet in #Euphoria
There be many a land lubber that knows naught of the pirate ways and gives direction by degree!
They know not how to box the compass!
Task description
Create a function that takes a heading in degrees and returns the correct 32-point compass heading.
Use the function to print and... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Write_a_PPM_file | Bitmap/Write a PPM file | Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| #Julia | Julia | using Images, FileIO
h, w = 50, 70
img = zeros(RGB{N0f8}, h, w)
img[10:40, 5:35] = colorant"skyblue"
for i in 26:50, j in (i-25):40
img[i, j] = colorant"sienna1"
end
save("data/bitmapWrite.ppm", img)
save("data/bitmapWrite.png", img) | Give a code snippet in #Julia
Using the data storage type defined on this page for raster images, write the image to a PPM file (binary P6 prefered).
(Read the definition of PPM file on Wikipedia.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Count_occurrences_of_a_substring | Count occurrences of a substring | Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
It should return an integer cou... | #Ruby | Ruby | def countSubstrings str, subStr
str.scan(subStr).length
end
p countSubstrings "the three truths", "th" #=> 3
p countSubstrings "ababababab", "abab" #=> 2 | Give a code snippet in #Ruby
Task
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
the first argument being the string to search, and
the second a substring to be searched for.
I... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Soundex | Soundex | Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
There is a major issue in many of the ... | #PicoLisp | PicoLisp | (de soundex (Str)
(pack
(pad -4
(cons
(uppc (char (char Str)))
(head 3
(let Last NIL
(extract
'((C)
(and
(setq C
(case (uppc C)
... | Give a code snippet in #PicoLisp
Soundex is an algorithm for creating indices for words based on their pronunciation.
Task
The goal is for homophones to be encoded to the same representation so that they can be matched despite minor differences in spelling (from the soundex Wikipedia article).
Caution
Ther... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/For_with_a_specified_step | Loops/For with a specified step |
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Increment loop index within loop b... | #OCaml | OCaml | # let for_step a b step fn =
let rec aux i =
if i <= b then begin
fn i;
aux (i+step)
end
in
aux a
;;
val for_step : int -> int -> int -> (int -> 'a) -> unit = <fun>
# for_step 0 8 2 (fun i -> Printf.printf " %d\n" i) ;;
0
2
4
6
8
- : unit = () | Give a code snippet in #OCaml
Task
Demonstrate a for-loop where the step-value is greater than one.
Related tasks
Loop over multiple arrays simultaneously
Loops/Break
Loops/Continue
Loops/Do-while
Loops/Downward for
Loops/For
Loops/For with a specified step
Loops/Foreach
Loops/Inc... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Anonymous_recursion | Anonymous recursion | While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwanted side-effects, and/or the f... | #Wart | Wart | def (fib n)
if (n >= 0)
(transform n :thru (afn (n)
(if (n < 2)
n
(+ (self n-1)
(self n-2))))) | Give a code snippet in #Wart
While implementing a recursive function, it often happens that we must resort to a separate helper function to handle the actual recursion.
This is usually the case when directly calling the current function would waste too many resources (stack space, execution time), causing unwante... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Flow-control_structures | Flow-control structures | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
Note that Conditional Struc... | #Nim | Nim | block outer:
for i in 0..1000:
for j in 0..1000:
if i + j == 3:
break outer | Give a code snippet in #Nim
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Task
Document common flow-control structures.
One common example of a flow-control structure is the goto construct.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Musical_scale | Musical scale | Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, Re, Mi, Fa, Sol, La, Si/Ti, Do(1 octa... | #Emacs_Lisp | Emacs Lisp | (defun play-scale (freq-list dur)
"Play a list of frequencies."
(setq header (unibyte-string ; AU header:
46 115 110 100 ; ".snd" magic number
0 0 0 24 ; start of data bytes
255 255 255 255 ; file size is unknown
0 0 0 3 ... | Give a code snippet in #Emacs_Lisp
Task
Output the 8 notes of the C major diatonic scale to the default musical sound device on the system. Specifically, pitch must be tuned to 12-tone equal temperament (12TET) with the modern standard A=440Hz.
These are the notes "C, D, E, F, G, A, B, C(1 octave higher)", or "Do, R... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Remove_lines_from_a_file | Remove lines from a file | Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remove the first two lines from th... | #Ring | Ring |
cStr = read("C:\Ring\bin\filename.txt")
aList = str2list(cStr)
see aList + nl
lineStart = 3
lineCount = 5
num = -1
for n = lineStart to lineStart+lineCount-1
num += 1
del(aList,n-num)
next
cStr = list2str(aList)
see cStr + nl
write("C:\Ring\bin\filename.txt",cStr)
| Give a code snippet in #Ring
Task
Remove a specific line or a number of lines from a file.
This should be implemented as a routine that takes three parameters (filename, starting line, and the number of lines to be removed).
For the purpose of this task, line numbers and the number of lines start at one, so to remo... | christopher/rosetta-code | |
http://rosettacode.org/wiki/9_billion_names_of_God_the_integer | 9 billion names of God the integer | This task is a variation of the short story by Arthur C. Clarke.
(Solvers should be aware of the consequences of completing this task.)
In detail, to specify what is meant by a “name”:
The integer 1 has 1 name “1”.
The integer 2 has 2 names “1+1”, and “2”.
The integer 3 has 3 names “1+1+1”, “2+1”, ... | #Dart | Dart | import 'dart:math';
List<BigInt> partitions(int n) {
var cache = List<List<BigInt>>.filled(1, List<BigInt>.filled(1, BigInt.from(1)), growable: true);
for(int length = cache.length; length < n + 1; length++) {
var row = List<BigInt>.filled(1, BigInt.from(0), growable: true);
for(int index = 1; index < len... | Give a code snippet in #Dart
This task is a variation of the short story by Arthur C. Clarke.
(Solvers should be aware of the consequences of completing this task.)
In detail, to specify what is meant by a “name”:
The integer 1 has 1 name “1”.
The integer 2 has 2 names “1+1”, and “2”.
The integer 3 has ... | 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
| #PicoLisp | PicoLisp |
> 0;
(3) Result: 0
> false;
(4) Result: 0
> 0;
(6) Result: 0
> !true;
(7) Result: 0
> true;
(8) Result: 1
> 1;
(9) Result: 1
>
| Give a code snippet in #PicoLisp
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/Handle_a_signal | Handle a signal | Most operating systems provide interrupt facilities, sometimes called signals either generated by the user or as a result of program failure or reaching a limit like file space.
Unhandled signals generally terminate a program in a disorderly manner.
Signal handlers are created so that the program behaves in a well-defi... | #Scala | Scala | import sun.misc.Signal
import sun.misc.SignalHandler
object SignalHandl extends App {
val start = System.nanoTime()
var counter = 0
Signal.handle(new Signal("INT"), new SignalHandler() {
def handle(sig: Signal) {
println(f"\nProgram execution took ${(System.nanoTime() - start) / 1e9f}%f seconds\n")
... | Give a code snippet in #Scala
Most operating systems provide interrupt facilities, sometimes called signals either generated by the user or as a result of program failure or reaching a limit like file space.
Unhandled signals generally terminate a program in a disorderly manner.
Signal handlers are created so that the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Floyd-Warshall_algorithm | Floyd-Warshall algorithm | The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been checked for loops, parallel ... | #zkl | zkl | fcn FloydWarshallWithPathReconstruction(dist){ // dist is munged
V:=dist[0].len();
next:=V.pump(List,V.pump(List,Void.copy).copy); // VxV matrix of Void
foreach u,v in (V,V){ if(dist[u][v]!=Void and u!=v) next[u][v] = v }
foreach k,i,j in (V,V,V){
a,b,c:=dist[i][j],dist[i][k],dist[k][j];
if( (a... | Give a code snippet in #zkl
The Floyd–Warshall algorithm is an algorithm for finding shortest paths in a weighted graph with positive or negative edge weights.
Task
Find the lengths of the shortest paths between all pairs of vertices of the given directed graph. Your code may assume that the input has already been... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Empty_string | Empty string | Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Other tasks related to string oper... | #ACL2 | ACL2 | (= (length str) 0) | Give a code snippet in #ACL2
Languages may have features for dealing specifically with empty strings
(those containing no characters).
Task
Demonstrate how to assign an empty string to a variable.
Demonstrate how to check that a string is empty.
Demonstrate how to check that a string is not empty.
Othe... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Semordnilap | Semordnilap | A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the total number of unique semordnilap ... | #Transd | Transd | #lang transd
MainModule: {
_start: (λ (with fs FileStream()
(open-r fs "/mnt/vault/tmp/unixdict.txt") )
(with v ( -|
(read-text fs)
(split)
(group-by (λ s String() -> String()
(ret (min s (reverse (cp s))))))
(values)
(filter where: (λ v Vector<String>() (... | Give a code snippet in #Transd
A semordnilap is a word (or phrase) that spells a different word (or phrase) backward. "Semordnilap" is a word that itself is a semordnilap.
Example: lager and regal
Task
This task does not consider semordnilap phrases, only single words.
Using only words from this list, report the tot... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Truncatable_primes | Truncatable primes | A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncatable prime as the numbers 7393, 7... | #ooRexx | ooRexx |
-- find largest left- & right-truncatable primes < 1 million.
-- an initial set of primes (not, at this time, we leave out 2 because
-- we'll automatically skip the even numbers. No point in doing a needless
-- test each time through
primes = .array~of(3, 5, 7, 11)
-- check all of the odd numbers up to 1,000,000
l... | Give a code snippet in #ooRexx
A truncatable prime is a prime number that when you successively remove digits from one end of the prime, you are left with a new prime number.
Examples
The number 997 is called a left-truncatable prime as the numbers 997, 97, and 7 are all prime.
The number 7393 is a right-truncata... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Digital_root/Multiplicative_digital_root | Digital root/Multiplicative digital root | The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\displaystyle n}
and
i
{\displaystyle i}
to
0
... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language |
ClearAll[mdr, mp, nums];
mdr[n_] := NestWhile[Times @@ IntegerDigits[#] &, n, # > 9 &];
mp[n_] := Length@NestWhileList[Times @@ IntegerDigits[#] &, n, # > 9 &] - 1;
TableForm[{#, mdr[#], mp[#]} & /@ {123321, 7739, 893, 899998},
TableHeadings -> {None, {"Number", "MDR", "MP"}}]
nums = ConstantArray[{}, 10];
For[i = ... | Give a code snippet in #Mathematica_.2F_Wolfram_Language
The multiplicative digital root (MDR) and multiplicative persistence (MP) of a number,
n
{\displaystyle n}
, is calculated rather like the Digital root except digits are multiplied instead of being added:
Set
m
{\displaystyle m}
to
n
{\dis... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Active_Directory/Search_for_a_user | Active Directory/Search for a user | Make sure you Connect to Active Directory
| #PHP | PHP | <?php
$l = ldap_connect('ldap.example.com');
ldap_set_option($l, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_set_option($l, LDAP_OPT_REFERRALS, false);
$bind = ldap_bind($l, 'me@example.com', 'password');
$base = 'dc=example, dc=com';
$criteria = '(&(objectClass=user)(sAMAccountName=username))';
$attributes = array('disp... | Give a code snippet in #PHP
Make sure you Connect to Active Directory
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Root_mean_square | Averages/Root mean square | Task[edit]
Compute the Root mean square of the numbers 1..10.
The root mean square is also known by its initials RMS (or rms), and as the quadratic mean.
The RMS is calculated as the mean of the squares of the numbers, square-rooted:
x
r
m
s
=
x
1
2
+
x
2
2
+
⋯
+
x
... | #OCaml | OCaml | let rms a =
sqrt (Array.fold_left (fun s x -> s +. x*.x) 0.0 a /.
float_of_int (Array.length a))
;;
rms (Array.init 10 (fun i -> float_of_int (i+1))) ;;
(* 6.2048368229954285 *) | Give a code snippet in #OCaml
Task[edit]
Compute the Root mean square of the numbers 1..10.
The root mean square is also known by its initials RMS (or rms), and as the quadratic mean.
The RMS is calculated as the mean of the squares of the numbers, square-rooted:
x
r
m
s
=
x
1
2
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/SHA-256 | SHA-256 | SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b785e5cc2f707d6468d7d1124cdfcf
| #OCaml | OCaml | let () =
let s = "Rosetta code" in
let digest = Sha256.string s in
print_endline (Sha256.to_hex digest) | Give a code snippet in #OCaml
SHA-256 is the recommended stronger alternative to SHA-1. See FIPS PUB 180-4 for implementation details.
Either by using a dedicated library or implementing the algorithm in your language, show that the SHA-256 digest of the string "Rosetta code" is: 764faf5c61ac315f1497f9dfa542713965b78... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Forward_difference | Forward difference | Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List B should have one fewer elem... | #Perl | Perl | sub dif {
my @s = @_;
map { $s[$_+1] - $s[$_] } 0 .. $#s-1
}
@a = qw<90 47 58 29 22 32 55 5 55 73>;
while (@a) { printf('%6d', $_) for @a = dif @a; print "\n" } | Give a code snippet in #Perl
Task
Provide code that produces a list of numbers which is the nth order forward difference, given a non-negative integer (specifying the order) and a list of numbers.
The first-order forward difference of a list of numbers A is a new list B, where Bn = An+1 - An.
List ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Take_notes_on_the_command_line | Take notes on the command line | Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TXT followed by a newline.
Then al... | #HicEst | HicEst | SYSTEM(RUN) ! start this script in RUN-mode
CHARACTER notes="Notes.txt", txt*1000
! Remove file name from the global variable $CMD_LINE:
EDIT(Text=$CMD_LINE, Mark1, Right=".hic ", Right=4, Mark2, Delete)
IF($CMD_LINE == ' ') THEN
READ(FIle=notes, LENgth=Lnotes)
IF( Lnotes ) THEN
WINDOW(WINdowhandle=hdl, T... | Give a code snippet in #HicEst
Take notes on the command line is part of Short Circuit's Console Program Basics selection.
Invoking NOTES without commandline arguments displays the current contents of the local NOTES.TXT if it exists.
If NOTES has arguments, the current date and time are appended to the local NOTES.TX... | 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... | #Simula | Simula | begin
integer i;
i:=1024;
while i>0 do
begin
outint(i,5);
i:=i//2-1
end
end | Give a code snippet in #Simula
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/Downwa... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Function_prototype | Function prototype | Some languages provide the facility to declare functions and subroutines through the use of function prototyping.
Task
Demonstrate the methods available for declaring prototypes within the language. The provided solutions should include:
An explanation of any placement restrictions for prototype declarations
A p... | #Perl | Perl | sub noargs(); # Declare a function with no arguments
sub twoargs($$); # Declare a function with two scalar arguments. The two sigils act as argument type placeholders
sub noargs :prototype(); # Using the :attribute syntax instead
sub twoargs :prototype($$); | Give a code snippet in #Perl
Some languages provide the facility to declare functions and subroutines through the use of function prototyping.
Task
Demonstrate the methods available for declaring prototypes within the language. The provided solutions should include:
An explanation of any placement restrictions f... | 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... | #Wren | Wren | class Box {
construct new(v) { _v = v }
v { _v }
v=(value) { _v = value }
}
var i = Box.new(0) // any initial value will do here
var sum = Fn.new { |i, lo, hi, term|
var temp = 0
i.v = lo
while (i.v <= hi) {
temp = temp + term.call()
i.v = i.v + 1
}
return temp
}
v... | Give a code snippet in #Wren
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 ALGO... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Call_a_function_in_a_shared_library | Call a function in a shared library | Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language function where the focus is c... | #Wren | Wren | /* call_shared_library_function.wren */
var RTLD_LAZY = 1
foreign class DL {
construct open(file, mode) {}
foreign call(symbol, arg)
foreign close()
}
class My {
static openimage(s) {
System.print("internal openimage opens %(s)...")
if (!__handle) __handle = 0
__handle ... | Give a code snippet in #Wren
Show how to call a function in a shared library (without dynamically linking to it at compile-time). In particular, show how to call the shared library function if the library is available, otherwise use an internal equivalent function.
This is a special case of calling a foreign language... | 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... | #PicoLisp | PicoLisp | (de perfect (N)
(let C 0
(for I (/ N 2)
(and (=0 (% N I)) (inc 'C I)) )
(= C N) ) ) | Give a code snippet in #PicoLisp
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 its... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pangram_checker | Pangram checker | Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task
Write a function or method to chec... | #MiniScript | MiniScript | sentences = ["The quick brown fox jumps over the lazy dog.",
"Peter Piper picked a peck of pickled peppers.",
"Waltz job vexed quick frog nymphs."]
alphabet = "abcdefghijklmnopqrstuvwxyz"
pangram = function (toCheck)
sentence = toCheck.lower
fail = false
for c in alphabet
if sentence.ind... | Give a code snippet in #MiniScript
Pangram checker
You are encouraged to solve this task according to the task description, using any language you may know.
A pangram is a sentence that contains all the letters of the English alphabet at least once.
For example: The quick brown fox jumps over the lazy dog.
Task... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Order_two_numerical_lists | Order two numerical lists | sorting
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
She... | #Elixir | Elixir | iex(1)> [1,2,3] < [1,2,3,4]
true
iex(2)> [1,2,3] < [1,2,4]
true | Give a code snippet in #Elixir
sorting
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Program_termination | Program termination |
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/destructors, run-on-exit hooks... | #PHP | PHP | if (problem)
exit(1); | Give a code snippet in #PHP
Task
Show the syntax for a complete stoppage of a program inside a conditional.
This includes all threads/processes which are part of your program.
Explain the cleanup (or lack thereof) caused by the termination (allocated memory, database connections, open files, object finalizers/d... | christopher/rosetta-code | |
http://rosettacode.org/wiki/String_prepend | String prepend |
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 |... | #Go | Go | s := "world!"
s = "Hello, " + s | Give a code snippet in #Go
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
Con... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Topological_sort | Topological 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
... | #JavaScript | JavaScript | const libs =
`des_system_lib std synopsys std_cell_lib des_system_lib dw02 dw01 ramlib ieee
dw01 ieee dw01 dware gtech
dw02 ieee dw02 dware
dw03 std synopsys dware dw03 dw02 dw01 ieee gtech
dw04 dw04 ieee dw01 dware gtech
dw05 dw05 ieee dware
d... | Give a code snippet in #JavaScript
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 |
Qui... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Gamma_function | Gamma function | Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/library function.
The Gamma funct... | #Perl | Perl | use strict;
use warnings;
use constant pi => 4*atan2(1, 1);
use constant e => exp(1);
# Normally would be: use Math::MPFR
# but this will use it if it's installed and ignore otherwise
my $have_MPFR = eval { require Math::MPFR; Math::MPFR->import(); 1; };
sub Gamma {
my $z = shift;
my $method = shift // 'l... | Give a code snippet in #Perl
Task
Implement one algorithm (or more) to compute the Gamma (
Γ
{\displaystyle \Gamma }
) function (in the real field only).
If your language has the function as built-in or you know a library which has it, compare your implementation's results with the results of the built-in/libr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Phrase_reversals | Phrase reversals | Task
Given a string of space separated words containing the following phrase:
rosetta code phrase reversal
Reverse the characters of the string.
Reverse the characters of each individual word in the string, maintaining original word order within the string.
Reverse the order of each word of the string, maintaini... | #Ada | Ada | <with Ada.Text_IO, Simple_Parse;
procedure Phrase_Reversal is
function Reverse_String (Item : String) return String is
Result : String (Item'Range);
begin
for I in Item'range loop
Result (Result'Last - I + Item'First) := Item (I);
end loop;
return Result;
end Reverse_String... | Give a code snippet in #Ada
Task
Given a string of space separated words containing the following phrase:
rosetta code phrase reversal
Reverse the characters of the string.
Reverse the characters of each individual word in the string, maintaining original word order within the string.
Reverse the order of each ... | christopher/rosetta-code |
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