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/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... | #Yabasic | Yabasic |
sub isPerfect(n)
if (n < 2) or mod(n, 2) = 1 then return false : endif
// asumimos que los números impares no son perfectos
sum = 0
for i = 1 to n-1
if mod(n,i) = 0 then sum = sum + i : endif
next i
if sum = n then return true else return false : endif
end sub
print "Los primeros 5 n... | Give a code snippet in #Yabasic
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 itse... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Spiral_matrix | Spiral matrix | Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
15 16 17 18 5
14 23 24 19 6
13 22 21 ... | #J | J | spiral =: ,~ $ [: /: }.@(2 # >:@i.@-) +/\@# <:@+: $ (, -)@(1&,)
spiral 5
0 1 2 3 4
15 16 17 18 5
14 23 24 19 6
13 22 21 20 7
12 11 10 9 8 | Give a code snippet in #J
Task
Produce a spiral array.
A spiral array is a square arrangement of the first N2 natural numbers, where the
numbers increase sequentially as you go around the edges of the array spiraling inwards.
For example, given 5, produce this array:
0 1 2 3 4
15 16 17 18 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/General_FizzBuzz | General FizzBuzz | Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along with the corresponding word to be ... | #Ruby | Ruby | def general_fizzbuzz(text)
num, *nword = text.split
num = num.to_i
dict = nword.each_slice(2).map{|n,word| [n.to_i,word]}
(1..num).each do |i|
str = dict.map{|n,word| word if i%n==0}.join
puts str.empty? ? i : str
end
end
text = <<EOS
20
3 Fizz
5 Buzz
7 Baxx
EOS
general_fizzbuzz(text) | Give a code snippet in #Ruby
Task
Write a generalized version of FizzBuzz that works for any list of factors, along with their words.
This is basically a "fizzbuzz" implementation where the user supplies the parameters.
The user will enter the max number, then they will enter the factors to be calculated along with... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Read_entire_file | Read entire file | Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incrementally instead
(in which case... | #Go | Go | import "io/ioutil"
data, err := ioutil.ReadFile(filename)
sv := string(data) | Give a code snippet in #Go
Task
Load the entire contents of some text file as a single string variable.
If applicable, discuss: encoding selection, the possibility of memory-mapping.
Of course, in practice one should avoid reading an entire file at once
if the file is large and the task can be accomplished incremen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pseudo-random_numbers/Xorshift_star | Pseudo-random numbers/Xorshift star | Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary bits of value shifted left or ri... | #Lua | Lua | function create()
local g = {
magic = 0x2545F4914F6CDD1D,
state = 0,
seed = function(self, num)
self.state = num
end,
next_int = function(self)
local x = self.state
x = x ~ (x >> 12)
x = x ~ (x << 25)
x = x ~ (x >> 2... | Give a code snippet in #Lua
Some definitions to help in the explanation
Floor operation
https://en.wikipedia.org/wiki/Floor_and_ceiling_functions
Greatest integer less than or equal to a real number.
Bitwise Logical shift operators (c-inspired)
https://en.wikipedia.org/wiki/Bitwise_operation#Bit_shifts
Binary bit... | 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... | #Ezhil | Ezhil |
நிரல்பாகம் fact ( n )
@( n == 0 ) ஆனால்
பின்கொடு 1
இல்லை
பின்கொடு n*fact( n - 1 )
முடி
முடி
பதிப்பி fact ( 10 )
| Give a code snippet in #Ezhil
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 n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Execute_Brain**** | Execute Brain**** | Execute Brain**** is an implementation of Brainf***.
Other implementations of Brainf***.
RCBF is a set of Brainf*** compilers and interpreters written for Rosetta Code in a variety of languages.
Below are links to each of the versions of RCBF.
An implementation need only properly implement the following instructions:... | #PureBasic | PureBasic | [ stack ] is switch.arg ( --> [ )
[ switch.arg put ] is switch ( x --> )
[ switch.arg release ] is otherwise ( --> )
[ switch.arg share != iff ]else[ done
otherwise ]'... | Give a code snippet in #PureBasic
Execute Brain**** is an implementation of Brainf***.
Other implementations of Brainf***.
RCBF is a set of Brainf*** compilers and interpreters written for Rosetta Code in a variety of languages.
Below are links to each of the versions of RCBF.
An implementation need only properly im... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_input/output | File input/output | File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file into a variable
how to write ... | #Perl | Perl | #!/usr/bin/perl
open my $fh_in, '<', 'input.txt' or die "could not open <input.txt> for reading: $!";
open my $fh_out, '>', 'output.txt' or die "could not open <output.txt> for writing: $!";
# '>' overwrites file, '>>' appends to file, just like in the shell
binmode $fh_out; # marks filehandle for binary content on... | Give a code snippet in #Perl
File input/output is part of Short Circuit's Console Program Basics selection.
Task
Create a file called "output.txt", and place in it the contents of the file "input.txt", via an intermediate variable.
In other words, your program will demonstrate:
how to read from a file in... | christopher/rosetta-code | |
http://rosettacode.org/wiki/XML/XPath | XML/XPath | Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store #45x10^3">
<section name="heal... | #XQuery | XQuery | (:
1. Retrieve the first "item" element
Notice the braces around //item. This evaluates first all item elements and then retrieving the first one.
Whithout the braces you get the first item for every section.
:)
let $firstItem := (//item)[1]
(: 2. Perform an action on each "price" element (print it out) :)
l... | Give a code snippet in #XQuery
Perform the following three XPath queries on the XML Document below:
//item[1]: Retrieve the first "item" element
//price/text(): Perform an action on each "price" element (print it out)
//name: Get an array of all the "name" elements
XML Document:
<inventory title="OmniCorp Store ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list | Search a list | Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that has multiple occurrences in ... | #Plain_English | Plain English | To run:
Start up.
Make an example haystack.
Find "b" in the example haystack giving a count.
Destroy the example haystack.
Write "The index of ""b"" is " then the count on the console.
Wait for the escape key.
Shut down.
A needle is a string.
Some hay is some strings.
A bale is a thing with some hay.
A haystack... | Give a code snippet in #Plain_English
Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Validate_International_Securities_Identification_Number | Validate International Securities Identification Number | An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct format, and the embedded c... | #COBOL | COBOL | >>SOURCE FORMAT FREE
*> this is gnucobol 2.0
identification division.
program-id. callISINtest.
data division.
working-storage section.
01 ISINtest-result binary-int.
procedure division.
start-callISINtest.
display 'should be valid ' with no advancing
call 'ISINtest' using 'US0378331005' ISINtest-res... | Give a code snippet in #COBOL
An International Securities Identification Number (ISIN) is a unique international identifier for a financial security such as a stock or bond.
Task
Write a function or program that takes a string as input, and checks whether it is a valid ISIN.
It is only valid if it has the correct... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Binary_search | Binary search | A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret number, and will only tell the p... | #11l | 11l | F binary_search(l, value)
V low = 0
V high = l.len - 1
L low <= high
V mid = (low + high) I/ 2
I l[mid] > value
high = mid - 1
E I l[mid] < value
low = mid + 1
E
R mid
R -1 | Give a code snippet in #11l
A binary search divides a range of values into halves, and continues to narrow down the field of search until the unknown value is found. It is the classic example of a "divide and conquer" algorithm.
As an analogy, consider the children's game "guess a number." The scorer has a secret num... | 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... | #MATLAB_.2F_Octave | MATLAB / Octave | isOdd = logical(bitand(N,1));
isEven = ~logical(bitand(N,1)); | Give a code snippet in #MATLAB_.2F_Octave
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 i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Word_frequency | Word frequency | Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to define what a letter is.
Undersc... | #PureBasic | PureBasic | EnableExplicit
Structure wordcount
wkey$
count.i
EndStructure
Define token.c, word$, idx.i, start.i, arg$
NewMap wordmap.i()
NewList wordlist.wordcount()
If OpenConsole("")
arg$ = ProgramParameter(0)
If arg$ = "" : End 1 : EndIf
start = ElapsedMilliseconds()
If ReadFile(0, arg$, #PB_Ascii)
Whi... | Give a code snippet in #PureBasic
Task
Given a text file and an integer n, print/display the n most
common words in the file (and the number of their occurrences) in decreasing frequency.
For the purposes of this task:
A word is a sequence of one or more contiguous letters.
You are free to defin... | 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 |... | #11l | 11l | V a = Int(input(‘Enter value of a: ’))
V b = Int(input(‘Enter value of b: ’))
I a < b
print(‘a is less than b’)
I a > b
print(‘a is greater than b’)
I a == b
print(‘a is equal to b’) | Give a code snippet in #11l
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
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/File_size | File size | Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| #FBSL | FBSL | #APPTYPE CONSOLE
PRINT FileLen("sync.log")
PRINT FileLen("\sync.log")
PAUSE
| Give a code snippet in #FBSL
Verify the size of a file called input.txt for a file in the current working directory, and another one in the file system root.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Church_numerals | Church numerals | Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied to the second argument at all.
C... | #J | J | chget=: {{(0;1;1;1) {:: y}}
chset=: {{
'A B'=.;y
'C D'=.B
'E F'=.D
<A;<C;<E;<<.x
}}
ch0=: {{
if.0=#y do.y=.;:'>:' end. NB. replace empty gerund with increment
0 chset y`:6^:2`''
}}
apply=: `:6
chNext=: {{(1+chget y) chset y}}
chAdd=: {{(x +&chget y) chset y}}
chSub=: {{(x -&chget y) chset y}}
chMu... | Give a code snippet in #J
Task
In the Church encoding of natural numbers, the number N is encoded by a function that applies its first argument N times to its second argument.
Church zero always returns the identity function, regardless of its first argument. In other words, the first argument is not applied to the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Search_a_list | Search a list | Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle that has multiple occurrences in ... | #Maple | Maple | haystack := ["Zig","Zag","Wally","Ronald","Bush","Krusty","Charlie","Bush","Bozo"]:
occurences := ListTools:-SearchAll(needle,haystack):
try
#first occurence
printf("The first occurence is at index %d\n", occurences[1]);
#last occurence, note that StringTools:-SearchAll()retuns a list of all occurences positions
pr... | Give a code snippet in #Maple
Task[edit]
Find the index of a string (needle) in an indexable, ordered collection of strings (haystack).
Raise an exception if the needle is missing.
If there is more than one occurrence then return the smallest index to the needle.
Extra credit
Return the largest index to a needle th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Keyboard_input/Flush_the_keyboard_buffer | Keyboard input/Flush the keyboard buffer | Flush the keyboard buffer.
This reads characters from the keyboard input and
discards them until there are no more currently buffered,
and then allows the program to continue.
The program must not wait for users to type anything.
| #PicoLisp | PicoLisp | (while (key 10)) | Give a code snippet in #PicoLisp
Flush the keyboard buffer.
This reads characters from the keyboard input and
discards them until there are no more currently buffered,
and then allows the program to continue.
The program must not wait for users to type anything.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #Factor | Factor | ( scratchpad ) { { 1 2 3 } { 4 5 6 } } flip .
{ { 1 4 } { 2 5 } { 3 6 } } | Give a code snippet in #Factor
Transpose an arbitrarily sized rectangular Matrix.
| 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.
| #D | D | import std.stdio, std.bigint;
BigInt sum35(in BigInt n) pure nothrow {
static BigInt sumMul(in BigInt n, in int f) pure nothrow {
immutable n1 = (f==n?n:(n - 1) ) / f;
return f * n1 * (n1 + 1) / 2;
}
return sumMul(n, 3) + sumMul(n, 5) - sumMul(n, 15);
}
void main() {
1.BigInt.sum35... | Give a code snippet in #D
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/Show_the_epoch | Show the epoch | Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scenes by the implementers), b... | #Go | Go | package main
import ("fmt"; "time")
func main() {
fmt.Println(time.Time{})
} | Give a code snippet in #Go
Task
Choose popular date libraries used by your language and show the epoch those libraries use.
A demonstration is preferable (e.g. setting the internal representation of the date to 0 ms/ns/etc., or another way that will still show the epoch even if it is changed behind the scen... | 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 ... | #Io | Io | multiply := method(a,b,a*b) | Give a code snippet in #Io
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 fro... | 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... | #E | E | pragma.enable("accumulator")
def isPerfectNumber(x :int) {
var sum := 0
for d ? (x % d <=> 0) in 1..!x {
sum += d
if (sum > x) { return false }
}
return sum <=> x
} | Give a code snippet in #E
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/Hello_world/Graphical | Hello world/Graphical |
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| #Vala | Vala | #!/usr/local/bin/vala --pkg gtk+-3.0
using Gtk;
void main(string[] args) {
Gtk.init(ref args);
var window = new Window();
window.title = "Goodbye, world!";
window.border_width = 10;
window.window_position = WindowPosition.CENTER;
window.set_default_size(350, 70);
window.destroy.connect(G... | Give a code snippet in #Vala
Task
Display the string Goodbye, World! on a GUI object (alert box, plain window, text area, etc.).
Related task
Hello world/Text
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Cuban_primes | Cuban primes | The name cuban has nothing to do with Cuba (the country), but has to do with the
fact that cubes (3rd powers) play a role in its definition.
Some definitions of cuban primes
primes which are the difference of two consecutive cubes.
primes of the form: (n+1)3 - n3.
primes of the form: n3 - ... | #Bracmat | Bracmat | ( ( cubanprimes
=
. !arg:(?N.?bigN)
& :?cubans
& (0.1.1):(?cube100k.?cube1.?count)
& 0:?i
& whl
' ( 1+!i:?i
& !i+1:?j
& !j^3:?cube2
& !cube2+-1*!cube1:?diff
& ( !diff^1/2:~(!diff^?)
| ( !count:~>!N
& !d... | Give a code snippet in #Bracmat
The name cuban has nothing to do with Cuba (the country), but has to do with the
fact that cubes (3rd powers) play a role in its definition.
Some definitions of cuban primes
primes which are the difference of two consecutive cubes.
primes of the form: (n+1)3 - n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dice_game_probabilities | Dice game probabilities | Two players have a set of dice each. The first player has nine dice with four faces each, with numbers one to four. The second player has six normal dice with six faces each, each face has the usual numbers from one to six.
They roll their dice and sum the totals of the faces. The player with the highest total wins (i... | #Java | Java | import java.util.Random;
public class Dice{
private static int roll(int nDice, int nSides){
int sum = 0;
Random rand = new Random();
for(int i = 0; i < nDice; i++){
sum += rand.nextInt(nSides) + 1;
}
return sum;
}
private static int diceGame(int p1Dice, int p1Sides, int p2Dice, int p2Sides, int roll... | Give a code snippet in #Java
Two players have a set of dice each. The first player has nine dice with four faces each, with numbers one to four. The second player has six normal dice with six faces each, each face has the usual numbers from one to six.
They roll their dice and sum the totals of the faces. The player ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Visualize_a_tree | Visualize a tree | A tree structure (i.e. a rooted, connected acyclic graph) is often used in programming.
It's often helpful to visually examine such a structure.
There are many ways to represent trees to a reader, such as:
indented text (à la unix tree command)
nested HTML tables
hierarchical GUI widgets
2D or ... | #C.23 | C# | using System;
public static class VisualizeTree
{
public static void Main() {
"A".t(
"B0".t(
"C1",
"C2".t(
"D".t("E1", "E2", "E3")),
"C3".t(
"F1",
"F2",
"F3".t("G"),
... | Give a code snippet in #C.23
A tree structure (i.e. a rooted, connected acyclic graph) is often used in programming.
It's often helpful to visually examine such a structure.
There are many ways to represent trees to a reader, such as:
indented text (à la unix tree command)
nested HTML tables
hierar... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Add_a_variable_to_a_class_instance_at_runtime | Add a variable to a class instance at runtime | Demonstrate how to dynamically add variables to an object (a class instance) at runtime.
This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metaprogramming with Ruby. This is re... | #Forth | Forth | include FMS-SI.f
include FMS-SILib.f
\ We can add any number of variables at runtime by adding
\ objects of any type to an instance at run time. The added
\ objects are then accessible via an index number.
:class foo
object-list inst-objects \ a dynamically growable object container
:m init: inst-objects i... | Give a code snippet in #Forth
Demonstrate how to dynamically add variables to an object (a class instance) at runtime.
This is useful when the methods/variables of an instance are based on a data file that isn't available until runtime. Hal Fulton gives an example of creating an OO CSV parser at An Exercise in Metapr... | 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... | #ooRexx | ooRexx |
/* REXX Compute bunch permutations of things elements */
Parse Arg bunch things
If bunch='?' Then
Call help
If bunch=='' Then bunch=3
If datatype(bunch)<>'NUM' Then Call help 'bunch ('bunch') must be numeric'
thing.=''
Select
When things='' Then things=bunch
When datatype(things)='NUM' Then Nop
Otherwise Do
... | Give a code snippet in #ooRexx
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/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 |... | #Common_Lisp | Common Lisp | (defmacro prependf (s &rest strs)
"Prepend the given string variable with additional strings. The string variable is modified in-place."
`(setf ,s (concatenate 'string ,@strs ,s)))
(defvar *str* "foo")
(prependf *str* "bar")
(format T "~a~%" *str*) | Give a code snippet in #Common_Lisp
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/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... | #Transact-SQL | Transact-SQL |
DECLARE @i INT = 1024;
WHILE @i >0
BEGIN
PRINT @i;
SET @i = @i / 2;
END;
| Give a code snippet in #Transact-SQL
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/... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Continued_fraction/Arithmetic/Construct_from_rational_number | Continued fraction/Arithmetic/Construct from rational number | Continued fraction arithmetic
The purpose of this task is to write a function
r
2
c
f
(
i
n
t
{\displaystyle {\mathit {r2cf}}(\mathrm {int} }
N
1
,
i
n
t
{\displaystyle N_{1},\mathrm {int} }
N
2
)
{\displaystyle N_{2})}
, or
r
2
c
f
(
F
r
a
c
t
i
o
n
{\displaystyle {\m... | #Clojure | Clojure | (defn r2cf [n d]
(if-not (= d 0) (cons (quot n d) (lazy-seq (r2cf d (rem n d))))))
; Example usage
(def demo '((1 2)
(3 1)
(23 8)
(13 11)
(22 7)
(-151 77)
(14142 10000)
(141421 100000)
(1414214 1000000)
(1414... | Give a code snippet in #Clojure
Continued fraction arithmetic
The purpose of this task is to write a function
r
2
c
f
(
i
n
t
{\displaystyle {\mathit {r2cf}}(\mathrm {int} }
N
1
,
i
n
t
{\displaystyle N_{1},\mathrm {int} }
N
2
)
{\displaystyle N_{2})}
, or
r
2
c
f
(
F
r
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitmap/Flood_fill | Bitmap/Flood fill | Implement a flood fill.
A flood fill is a way of filling an area using color banks to define the contained area or a target color which "determines" the area (the valley that can be flooded; Wikipedia uses the term target color). It works almost like a water flooding from a point towards the banks (or: inside the vall... | #Nim | Nim | import bitmap
proc floodFill*(img: Image; initPoint: Point; targetColor, replaceColor: Color) =
var stack: seq[Point]
let width = img.w
let height = img.h
if img[initPoint.x, initPoint.y] != targetColor:
return
stack.add(initPoint)
while stack.len > 0:
var w, e: Point
let pt = stack.po... | Give a code snippet in #Nim
Implement a flood fill.
A flood fill is a way of filling an area using color banks to define the contained area or a target color which "determines" the area (the valley that can be flooded; Wikipedia uses the term target color). It works almost like a water flooding from a point towards t... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Prime_decomposition | Prime decomposition | The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the prime decomposition of a given ... | #Simula | Simula |
EXTERNAL CLASS BIGNUM;
BIGNUM
BEGIN
CLASS TEXTLIST;
BEGIN
CLASS TEXTARRAY(N); INTEGER N;
BEGIN
TEXT ARRAY DATA(1:N);
END TEXTARRAY;
PROCEDURE EXPAND(N); INTEGER N;
BEGIN
REF(TEXTARRAY) NEWARR;
INTEGER I;
NEWARR :- NEW TE... | Give a code snippet in #Simula
The prime decomposition of a number is defined as a list of prime numbers
which when all multiplied together, are equal to that number.
Example
12 = 2 × 2 × 3, so its prime decomposition is {2, 2, 3}
Task
Write a function which returns an array or collection which contains the... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arrays | Arrays | This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and retrieve an element (if available,... | #SNOBOL4 | SNOBOL4 | ar = ARRAY("3,2") ;* 3 rows, 2 columns
fill i = LT(i, 3) i + 1 :F(display)
ar<i,1> = i
ar<i,2> = i "-count" :(fill)
display ;* fail on end of array
j = j + 1
OUTPUT = "Row " ar<j,1> ": " ar<j,2>
+ :S(display)
END | Give a code snippet in #SNOBOL4
This task is about arrays.
For hashes or associative arrays, please see Creating an Associative Array.
For a definition and in-depth discussion of what an array is, see Array.
Task
Show basic array syntax in your language.
Basically, create an array, assign a value to it, and ret... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Morse_code | Morse code | Morse code
It has been in use for more than 175 years — longer than any other electronic encoding system.
Task
Send a string as audible Morse code to an audio device (e.g., the PC speaker).
As the standard Morse code does not contain all possible characters,
you may either ignore unknown characters in the file... | #Clojure | Clojure | (import [javax.sound.sampled AudioFormat AudioSystem SourceDataLine])
(defn play [sample-rate bs]
(let [af (AudioFormat. sample-rate 8 1 true true)]
(doto (AudioSystem/getSourceDataLine af)
(.open af sample-rate)
.start
(.write bs 0 (count bs))
.drain
.close)))
(defn note [hz sam... | Give a code snippet in #Clojure
Morse code
It has been in use for more than 175 years — longer than any other electronic encoding system.
Task
Send a string as audible Morse code to an audio device (e.g., the PC speaker).
As the standard Morse code does not contain all possible characters,
you may either igno... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #Aime | Aime | real
dp(list a, list b)
{
real p, v;
integer i;
p = 0;
for (i, v in a) {
p += v * b[i];
}
p;
}
integer
main(void)
{
o_(dp(list(1r, 3r, -5r), list(4r, -2r, -1r)), "\n");
0;
} | Give a code snippet in #Aime
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Monty_Hall_problem | Monty Hall problem |
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for the time being.
The game show hos... | #PL.2FI | PL/I | *process source attributes xref;
ziegen: Proc Options(main);
/* REXX ***************************************************************
* 30.08.2013 Walter Pachl derived from Java
**********************************************************************/
Dcl (switchWins,stayWins) Bin Fixed(31) Init(0);
Dcl doors(3) Bin... | Give a code snippet in #PL.2FI
Suppose you're on a game show and you're given the choice of three doors.
Behind one door is a car; behind the others, goats.
The car and the goats were placed randomly behind the doors before the show.
Rules of the game
After you have chosen a door, the door remains closed for th... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Thiele%27s_interpolation_formula | Thiele's interpolation formula |
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Thiele's interpolation formula is an interpolation ... | #Phix | Phix | constant N = 32,
N2 = (N * (N - 1) / 2),
STEP = 0.05
constant inf = 1e300*1e300,
nan = -(inf/inf)
sequence {xval, t_sin, t_cos, t_tan} = repeat(repeat(0,N),4)
for i=1 to N do
xval[i] = (i-1) * STEP
t_sin[i] = sin(xval[i])
t_cos[i] = cos(xval[i])
t_tan[i] = t_sin[i] / t_c... | Give a code snippet in #Phix
This page uses content from Wikipedia. The original article was at Thiele's interpolation formula. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Thiele's interpolatio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Averages/Mean_time_of_day | Averages/Mean time of day | Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the ideas of Averages/Mean angle
compute ... | #Python | Python | from cmath import rect, phase
from math import radians, degrees
def mean_angle(deg):
return degrees(phase(sum(rect(1, radians(d)) for d in deg)/len(deg)))
def mean_time(times):
t = (time.split(':') for time in times)
seconds = ((float(s) + int(m) * 60 + int(h) * 3600)
for h, m, s in t)... | Give a code snippet in #Python
Task[edit]
A particular activity of bats occurs at these times of the day:
23:00:17, 23:40:20, 00:12:45, 00:17:19
Using the idea that there are twenty-four hours in a day,
which is analogous to there being 360 degrees in a circle,
map times of day to and from angles;
and using the ideas... | 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
| #CLU | CLU | % Functions can be passed to other functions using the 'proctype'
% type generator. The same works for iterators, using 'itertype'
% Here are two functions
square = proc (n: int) returns (int) return (n*n) end square
cube = proc (n: int) returns (int) return (n*n*n) end cube
% Here is a function that takes another ... | Give a code snippet in #CLU
Task
Pass a function as an argument to another function.
Related task
First-class functions
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Dutch_national_flag_problem | Dutch national flag problem |
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the colours in the Dutch national fla... | #BaCon | BaCon | DECLARE color$[] = { "red", "white", "blue" }
DOTIMES 16
ball$ = APPEND$(ball$, 0, color$[RANDOM(3)] )
DONE
PRINT "Unsorted: ", ball$
PRINT " Sorted: ", REPLACE$(SORT$(REPLACE$(ball$, "blue", "z")), "z", "blue") | Give a code snippet in #BaCon
The Dutch national flag is composed of three coloured bands in the order:
red (top)
then white, and
lastly blue (at the bottom).
The problem posed by Edsger Dijkstra is:
Given a number of red, blue and white balls in random order, arrange them in the order of the co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Address_of_a_variable | Address of a variable |
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 |... | #Kotlin | Kotlin | // Kotlin Native v0.5
import kotlinx.cinterop.*
fun main(args: Array<String>) {
val intVar = nativeHeap.alloc<IntVar>()
intVar.value = 42
with(intVar) { println("Value is $value, address is $rawPtr") }
nativeHeap.free(intVar)
} | Give a code snippet in #Kotlin
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitcoin/public_point_to_address | Bitcoin/public point to address | Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in order to have a 64 byte-longed st... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
include "bytedata.s7i";
include "msgdigest.s7i";
include "encoding.s7i";
const func string: publicPointToAddress (in string: x, in string: y) is func
result
var string: address is "";
begin
address := "\4;" & hex2Bytes(x) & hex2Bytes(y);
address := "\0;" & ripemd160(sha... | Give a code snippet in #Seed7
Bitcoin uses a specific encoding format to encode the digest of an elliptic curve public point into a short ASCII string. The purpose of this task is to perform such a conversion.
The encoding steps are:
take the X and Y coordinates of the given public point, and concatenate them in or... | christopher/rosetta-code | |
http://rosettacode.org/wiki/FizzBuzz | FizzBuzz | Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBuzz (instead of the number)
... | #Nemerle | Nemerle | using System;
using System.Console;
module FizzBuzz
{
FizzBuzz(x : int) : string
{
|x when x % 15 == 0 => "FizzBuzz"
|x when x % 5 == 0 => "Buzz"
|x when x % 3 == 0 => "Fizz"
|_ => $"$x"
}
Main() : void
{
foreach (i in [1 .. 100])
... | Give a code snippet in #Nemerle
Task
Write a program that prints the integers from 1 to 100 (inclusive).
But:
for multiples of three, print Fizz (instead of the number)
for multiples of five, print Buzz (instead of the number)
for multiples of both three and five, print FizzBu... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Harmonic_series | Harmonic series |
This page uses content from Wikipedia. The original article was at Harmonic number. 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)
In mathematics, the n-th harmonic number is the sum of the recipr... | #Wren | Wren | import "/big" for BigRat
import "/fmt" for Fmt
var harmonic = Fn.new { |n| (1..n).reduce(BigRat.zero) { |sum, i| sum + BigRat.one/i } }
BigRat.showAsInt = true
System.print("The first 20 harmonic numbers and the 100th, expressed in rational form, are:")
var numbers = (1..20).toList
numbers.add(100)
for (i in number... | Give a code snippet in #Wren
This page uses content from Wikipedia. The original article was at Harmonic number. 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)
In mathematics, the n-th harmonic n... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sockets | Sockets | For this exercise a program is open a socket to localhost on port 256 and send the message "hello socket world" before closing the socket.
Catching any exceptions or errors is not required.
| #Julia | Julia |
socket = connect("localhost",256)
write(socket, "hello socket world")
close(socket)
| Give a code snippet in #Julia
For this exercise a program is open a socket to localhost on port 256 and send the message "hello socket world" before closing the socket.
Catching any exceptions or errors is not required.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Statistics/Basic | Statistics/Basic | Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ,n\,\!}
, the mean is
x
¯... | #Haskell | Haskell | import Data.Foldable (foldl') --'
import System.Random (randomRs, newStdGen)
import Control.Monad (zipWithM_)
import System.Environment (getArgs)
intervals :: [(Double, Double)]
intervals = map conv [0 .. 9]
where
xs = [0.0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0]
conv s =
let [h, l] = take ... | Give a code snippet in #Haskell
Statistics is all about large groups of numbers.
When talking about a set of sampled data, most frequently used is their mean value and standard deviation (stddev).
If you have set of data
x
i
{\displaystyle x_{i}}
where
i
=
1
,
2
,
…
,
n
{\displaystyle i=1,2,\ldots ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Recursively | Walk a directory/Recursively | Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a directory/Non-recursively ... | #PHP | PHP | function findFiles($dir = '.', $pattern = '/./'){
$prefix = $dir . '/';
$dir = dir($dir);
while (false !== ($file = $dir->read())){
if ($file === '.' || $file === '..') continue;
$file = $prefix . $file;
if (is_dir($file)) findFiles($file, $pattern);
if (preg_match($pattern, $file)){
echo $f... | Give a code snippet in #PHP
Task
Walk a given directory tree and print files matching a given pattern.
Note: This task is for recursive methods. These tasks should read an entire directory tree, not a single directory.
Note: Please be careful when running any code examples found here.
Related task
Walk a... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Horizontal_sundial_calculations | Horizontal sundial calculations | Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, aka Ernest Legouve Reef), wit... | #Nim | Nim | import rdstdin, strutils, math, strformat
let lat = parseFloat readLineFromStdin "Enter latitude => "
let lng = parseFloat readLineFromStdin "Enter longitude => "
let med = parseFloat readLineFromStdin "Enter legal meridian => "
echo ""
let slat = sin lat.degToRad
echo &" sine of latitude: {slat:.3f... | Give a code snippet in #Nim
Task
Create a program that calculates the hour, sun hour angle, dial hour line angle from 6am to 6pm for an operator entered location.
For example, the user is prompted for a location and inputs the latitude and longitude 4°57′S 150°30′W (4.95°S 150.5°W of Jules Verne's Lincoln Island, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Display_a_linear_combination | Display a linear combination | Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
,
creates a string representing t... | #Kotlin | Kotlin | // version 1.1.2
fun linearCombo(c: IntArray): String {
val sb = StringBuilder()
for ((i, n) in c.withIndex()) {
if (n == 0) continue
val op = when {
n < 0 && sb.isEmpty() -> "-"
n < 0 -> " - "
n > 0 && sb.isEmpty() -> ""
else ... | Give a code snippet in #Kotlin
Task
Display a finite linear combination in an infinite vector basis
(
e
1
,
e
2
,
…
)
{\displaystyle (e_{1},e_{2},\ldots )}
.
Write a function that, when given a finite list of scalars
(
α
1
,
α
2
,
…
)
{\displaystyle (\alpha ^{1},\alpha ^{2},\ldots )}
, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Vigen%C3%A8re_cipher | Vigenère cipher | Task
Implement a Vigenère cypher, both encryption and decryption.
The program should handle keys and text of unequal length,
and should capitalize everything and discard non-alphabetic characters.
(If your program handles non-alphabetic characters in another way,
make a note of it.)
Related tasks
Caesar ... | #C.2B.2B | C++ | #include <iostream>
#include <string>
using namespace std;
class Vigenere
{
public:
string key;
Vigenere(string key)
{
for(int i = 0; i < key.size(); ++i)
{
if(key[i] >= 'A' && key[i] <= 'Z')
this->key += key[i];
else if(key[i] >= 'a' && key[i] <= 'z')
this->key += key[i] +... | Give a code snippet in #C.2B.2B
Task
Implement a Vigenère cypher, both encryption and decryption.
The program should handle keys and text of unequal length,
and should capitalize everything and discard non-alphabetic characters.
(If your program handles non-alphabetic characters in another way,
make a note of ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Base64_decode_data | Base64 decode data | See Base64 encode data.
Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file.
When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output with incorrect padding. Obviously... | #QB64 | QB64 | Option _Explicit
Dim As String udata, decoded
udata = "VG8gZXJyIGlzIGh1bWFuLCBidXQgdG8gcmVhbGx5IGZvdWwgdGhpbmdzIHVwIHlvdSBuZWVkIGEgY29tcHV0ZXIuCiAgICAtLVBhdWwgUi5FaHJsaWNo"
decoded = decode(udata)
Print udata
Print decoded
Function findIndex& (value As _Unsigned _Byte)
If Asc("A") <= value And value <= Asc(... | Give a code snippet in #QB64
See Base64 encode data.
Now write a program that takes the output of the Base64 encode data task as input and regenerate the original file.
When working on the VBA implementation I found several 'solutions' on the net, including one from the software maker himself, that showed output wit... | 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... | #Mathematica_.2F_Wolfram_Language | Mathematica / Wolfram Language | print "Hello World!" | Give a code snippet in #Mathematica_.2F_Wolfram_Language
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 lan... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Total_circles_area | Total circles area | Total circles area
You are encouraged to solve this task according to the task description, using any language you may know.
Example circles
Example circles filtered
Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (or a little more) decimal dig... | #zkl | zkl | circles:=File("circles.txt").pump(List,'wrap(line){
line.split().apply("toFloat") // L(x,y,r)
});
# compute the bounding box of the circles
x_min:=(0.0).min(circles.apply(fcn([(x,y,r)]){ x - r })); // (0) not used, just the list of numbers
x_max:=(0.0).max(circles.apply(fcn([(x,y,r)]){ x + r }));
y_min:=(0.0).m... | Give a code snippet in #zkl
Total circles area
You are encouraged to solve this task according to the task description, using any language you may know.
Example circles
Example circles filtered
Given some partially overlapping circles on the plane, compute and show the total area covered by them, with four or six (... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Grayscale_image | Grayscale image | Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To get luminance of a color u... | #R | R | # Conversion from Grey to RGB uses the following code
setAs("pixmapGrey", "pixmapRGB",
function(from, to){
z = new(to, as(from, "pixmap"))
z@red = from@grey
z@green = from@grey
z@blue = from@grey
z@channels = c("red", "green", "blue")
z
})
# Conversion from RGB to grey uses built-in coefficien... | Give a code snippet in #R
Many image processing algorithms are defined for grayscale (or else monochromatic) images.
Task
Extend the data storage type defined on this page to support grayscale images.
Define two operations, one to convert a color image to a grayscale image and one for the backward conversion.
To... | 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 ... | #StreamIt | StreamIt | void->int feedbackloop Fib {
join roundrobin(0,1);
body in->int filter {
work pop 1 push 1 peek 2 { push(peek(0) + peek(1)); pop(); }
};
loop Identity<int>;
split duplicate;
enqueue(0);
enqueue(1);
} | Give a code snippet in #StreamIt
The Fibonacci sequence is a sequence Fn of natural numbers defined recursively:
F0 = 0
F1 = 1
Fn = Fn-1 + Fn-2, if n>1
Task
Write a function to generate the nth Fibonacci number.
Solutions can be iterative or recursive (though recursive solutions ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Numbers_with_equal_rises_and_falls | Numbers with equal rises and falls | When a number is written in base 10, adjacent digits may "rise" or "fall" as the number is read (usually from left to right).
Definition
Given the decimal digits of the number are written as a series d:
A rise is an index i such that d(i) < d(i+1)
A fall is an index i such that ... | #CLU | CLU | % Find how many rises and falls a number has
rises_falls = proc (n: int) returns (int,int)
rises: int := 0
falls: int := 0
while n >= 10 do
dl: int := n//10
n := n / 10
dh: int := n//10
if dh < dl then rises := rises + 1
elseif dl < dh then falls := falls + 1
... | Give a code snippet in #CLU
When a number is written in base 10, adjacent digits may "rise" or "fall" as the number is read (usually from left to right).
Definition
Given the decimal digits of the number are written as a series d:
A rise is an index i such that d(i) < d(i+1)
A fall i... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Loops/Nested | Loops/Nested | Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is met.
Specifically, this task als... | #Kotlin | Kotlin | import java.util.Random
fun main(args: Array<String>) {
val r = Random()
val a = Array(10) { IntArray(10) { r.nextInt(20) + 1 } }
println("array:")
for (i in a.indices) println("row $i: " + a[i].asList())
println("search:")
Outer@ for (i in a.indices) {
print("row $i: ")
for ... | Give a code snippet in #Kotlin
Show a nested loop which searches a two-dimensional array filled with random numbers uniformly distributed over
[
1
,
…
,
20
]
{\displaystyle [1,\ldots ,20]}
.
The loops iterate rows and columns of the array printing the elements until the value
20
{\displaystyle 20}
is m... | 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
... | #Sidef | Sidef | func print_topo_sort (deps) {
var ba = Hash.new;
deps.each { |before, afters|
afters.each { |after|
if (before != after) {
ba{before}{after} = 1;
};
ba{after} \\= Hash.new;
}
};
loop {
var afters = ba.keys.grep {|k| ba{k}.valu... | 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/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... | #Red | Red | fac: function [n][r: 1 repeat i n [r: r * i] r]
fac: function [n][repeat i also n n: 1 [n: n * i] n] | Give a code snippet in #Red
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 num... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Bitwise_operations | Bitwise operations |
Basic Data Operation
This is a basic data operation. It represents a fundamental action on a basic data type.
You may see other such operations in the Basic Data Operations category, or:
Integer Operations
Arithmetic |
Comparison
Boolean Operations
Bitwise |
Logical
String Operations
Concatenation |
Interpolation |... | #Red | Red | Red [Source: https://github.com/vazub/rosetta-red]
a: 10
b: 2
print [
pad "a =" 10 a newline
pad "b =" 10 b newline
pad "a AND b:" 10 a and b newline
pad "a OR b:" 10 a or b newline
pad "a XOR b:" 10 a xor b newline
pad "NOT a:" 10 complement a newline
pad "a >>> b:" 10 a >>> b newline
pad "a >> b:" 10 a >>... | Give a code snippet in #Red
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
Co... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Dot_product | Dot product | Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, -1]
If implementing the dot ... | #ALGOL_W | ALGOL W | begin
% computes the dot product of two equal length integer vectors %
% (single dimension arrays ) the length of the vectors must be specified %
% in length. %
integer procedure integerDotProduct( integer array a ( * )
... | Give a code snippet in #ALGOL_W
Task
Create a function/use an in-built function, to compute the dot product, also known as the scalar product of two vectors.
If possible, make the vectors of arbitrary length.
As an example, compute the dot product of the vectors:
[1, 3, -5] and
[4, -2, ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Comments | Comments | Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| #PureBasic | PureBasic | ;comments come after an unquoted semicolon and last until the end of the line
foo = 5 ;This is a comment
c$ = ";This is not a comment" ;This is also a comment | Give a code snippet in #PureBasic
Task
Show all ways to include text in a language source file
that's completely ignored by the compiler or interpreter.
Related tasks
Documentation
Here_document
See also
Wikipedia
xkcd (Humor: hand gesture denoting // for "commenting out" people.)
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Bulls_and_cows | Bulls and cows | Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the guess is the same as the random... | #Forth | Forth | include random.fs
create hidden 4 allot
: ok? ( str -- ? )
dup 4 <> if 2drop false exit then
1 9 lshift 1- -rot
bounds do
i c@ '1 -
dup 0 9 within 0= if 2drop false leave then
1 swap lshift over and
dup 0= if nip leave then
xor
loop 0<> ;
: init
begin
hidden 4 bounds do 9 random ... | Give a code snippet in #Forth
Bulls and Cows
Task
Create a four digit random number from the digits 1 to 9, without duplication.
The program should:
ask for guesses to this number
reject guesses that are malformed
print the score for the guess
The score is computed as:
The player wins if the ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Solve_a_Hidato_puzzle | Solve a Hidato puzzle | The task is to write a program which solves Hidato (aka Hidoku) puzzles.
The rules are:
You are given a grid with some numbers placed in it. The other squares in the grid will be blank.
The grid is not necessarily rectangular.
The grid may have holes in it.
The grid is always connected.
The number “1” is always ... | #D | D | import std.stdio, std.array, std.conv, std.algorithm, std.string;
int[][] board;
int[] given, start;
void setup(string s) {
auto lines = s.splitLines;
auto cols = lines[0].split.length;
auto rows = lines.length;
given.length = 0;
board = new int[][](rows + 2, cols + 2);
foreach (row; board... | Give a code snippet in #D
The task is to write a program which solves Hidato (aka Hidoku) puzzles.
The rules are:
You are given a grid with some numbers placed in it. The other squares in the grid will be blank.
The grid is not necessarily rectangular.
The grid may have holes in it.
The grid is always connected.... | 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... | #J | J | removeLines=: 4 :0
'count start'=. x
file=. boxxopen y
lines=. <;.2 fread file
(;lines {~ <<< (start-1)+i.count) fwrite file
) | Give a code snippet in #J
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 ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Luhn_test_of_credit_card_numbers | Luhn test of credit card numbers | The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of the digits in the number.
Tak... | #COBOL | COBOL | IDENTIFICATION DIVISION.
PROGRAM-ID. LUHNTEST.
ENVIRONMENT DIVISION.
INPUT-OUTPUT SECTION.
data division.
WORKING-STORAGE SECTION.
01 inp-card.
03 inp-card-ch pic x(01) occurs 20 times.
01 ws-result pic 9(01).
88 pass-luhn-test... | Give a code snippet in #COBOL
The Luhn test is used by some credit card companies to distinguish valid credit card numbers from what could be a random selection of digits.
Those companies using credit card numbers that can be validated by the Luhn test have numbers that pass the following test:
Reverse the order of... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Cheryl%27s_birthday | Cheryl's birthday | Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then tells Albert the month of birth, ... | #Ada | Ada | with Ada.Text_IO; use Ada.Text_IO;
procedure Main is
type Months is
(January, February, March, April, May, June, July, August, September,
November, December);
type day_num is range 1 .. 31;
type birthdate is record
Month : Months;
Day : day_num;
Active : Boolean;
end recor... | Give a code snippet in #Ada
Albert and Bernard just became friends with Cheryl, and they want to know when her birthday is.
Cheryl gave them a list of ten possible dates:
May 15, May 16, May 19
June 17, June 18
July 14, July 16
August 14, August 15, August 17
Cheryl then tells Al... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Terminal_control/Clear_the_screen | Terminal control/Clear the screen | Task
Clear the terminal window.
| #jq | jq | "\u001B[2J" | Give a code snippet in #jq
Task
Clear the terminal window.
| 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... | #TUSCRIPT | TUSCRIPT |
$$ MODE TUSCRIPT
text="In olden times when wishing still helped one, there lived a king whose daughters were all beautiful, but the youngest was so beautiful that the sun itself, which has seen so much, was astonished whenever it shone in her face. Close by the king's castle lay a great dark forest, and under an old... | Give a code snippet in #TUSCRIPT
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 p... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Special_characters | Special characters | Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it to be used as a normal charact... | #Seed7 | Seed7 | audible alert BEL \a backslash (\) \\
backspace BS \b apostrophe (') \'
escape ESC \e double quote (") \"
formfeed FF \f
newline NL (LF) \n control-A \A
carriage return CR \r ...
horizo... | Give a code snippet in #Seed7
Special characters are symbols (single characters or sequences of characters) that have a "special" built-in meaning in the language and typically cannot be used in identifiers.
Escape sequences are methods that the language uses to remove the special meaning from the symbol, enabling it... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Walk_a_directory/Non-recursively | Walk a directory/Non-recursively | Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory, not an entire directory tree.
... | #Rascal | Rascal | import IO;
public void Walk(loc a, str pattern){
for (entry <- listEntries(a))
endsWith(entry, pattern) ? println(entry);
} | Give a code snippet in #Rascal
Task
Walk a given directory and print the names of files matching a given pattern.
(How is "pattern" defined? substring match? DOS pattern? BASH pattern? ZSH pattern? Perl regular expression?)
Note: This task is for non-recursive methods. These tasks should read a single directory,... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Y_combinator | Y combinator | In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state of a variable and this variable's stat... | #CoffeeScript | CoffeeScript | Y = (f) -> g = f( (t...) -> g(t...) ) | Give a code snippet in #CoffeeScript
In strict functional programming and the lambda calculus, functions (lambda expressions) don't have state and are only allowed to refer to arguments of enclosing functions.
This rules out the usual definition of a recursive function wherein a function is associated with the state ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Variables | Variables | Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| #Phix | Phix | <-------- object --------->
| |
+-atom +-sequence
| |
+-integer +-string
| Give a code snippet in #Phix
Task
Demonstrate a language's methods of:
variable declaration
initialization
assignment
datatypes
scope
referencing, and
other variable related facilities
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Memory_allocation | Memory allocation | Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| #360_Assembly | 360 Assembly |
* Request to Get Storage Managed by "GETMAIN" Supervisor Call (SVC 4)
LA 1,PLIST Point Reg 1 to GETMAIN/FREEMAIN Parm List
SVC 4 Issue GETMAIN SVC
LTR 15,15 Register 15 = 0?
BZ GOTSTG Yes: Got Storage
* [...] No: Handle ... | Give a code snippet in #360_Assembly
Task
Show how to explicitly allocate and deallocate blocks of memory in your language.
Show access to different types of memory (i.e., heap, stack, shared, foreign) if applicable.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Strip_comments_from_a_string | Strip comments from a string | Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.
Whitespace debacle: There is s... | #Action.21 | Action! | PROC Strip(CHAR ARRAY text,chars,result)
BYTE i,j,pos,found
pos=text(0)
FOR i=1 TO text(0)
DO
found=0
FOR j=1 TO chars(0)
DO
IF text(i)=chars(j) THEN
found=1 EXIT
FI
OD
IF found THEN
pos=i-1 EXIT
FI
OD
WHILE pos>0 AND text(pos)='
DO
pos==-1
OD
S... | Give a code snippet in #Action.21
Strip comments from a string
You are encouraged to solve this task according to the task description, using any language you may know.
The task is to remove text that follow any of a set of comment markers, (in these examples either a hash or a semicolon) from a string or input line.... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Shell_one-liner | Shell one-liner | Task
Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length.
Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementations which have different comman... | #zkl | zkl | echo 'println("Hello World ",5+6)' | zkl | Give a code snippet in #zkl
Task
Show how to specify and execute a short program in the language from a command shell, where the input to the command shell is only one line in length.
Avoid depending on the particular shell or operating system used as much as is reasonable; if the language has notable implementation... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Fork | Fork | Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| #Tcl | Tcl | package require Expect
# or
package require Tclx
for {set i 0} {$i < 100} {incr i} {
set pid [fork]
switch $pid {
-1 {
puts "Fork attempt #$i failed."
}
0 {
puts "I am child process #$i."
exit
}
default {
puts "The parent ... | Give a code snippet in #Tcl
Task
Spawn a new process which can run simultaneously with, and independently of, the original parent process.
| 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... | #Groovy | Groovy | static def removeLines(String filename, int startingLine, int lineCount) {
def sourceFile = new File(filename).getAbsoluteFile()
def outputFile = File.createTempFile("remove", ".tmp", sourceFile.getParentFile())
outputFile.withPrintWriter { outputWriter ->
sourceFile.eachLine { line, lineNumber ->... | Give a code snippet in #Groovy
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 re... | 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... | #S-lang | S-lang | require("chksum");
print(sha1sum("Rosetta Code")); | Give a code snippet in #S-lang
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 id... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Matrix_transposition | Matrix transposition | Transpose an arbitrarily sized rectangular Matrix.
| #Go | Go | package main
import (
"fmt"
"gonum.org/v1/gonum/mat"
)
func main() {
m := mat.NewDense(2, 3, []float64{
1, 2, 3,
4, 5, 6,
})
fmt.Println(mat.Formatted(m))
fmt.Println()
fmt.Println(mat.Formatted(m.T()))
} | Give a code snippet in #Go
Transpose an arbitrarily sized rectangular Matrix.
| christopher/rosetta-code | |
http://rosettacode.org/wiki/Determine_if_a_string_has_all_unique_characters | Determine if a string has all unique characters | Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are unique
indicate if or which character is duplicated and where
display each string and its length (as the strings are being ... | #zkl | zkl | fcn stringUniqueness(str){ // Does not handle Unicode
sz,unique,uz,counts := str.len(), str.unique(), unique.len(), str.counts();
println("Length %d: \"%s\"".fmt(sz,str));
if(sz==uz or uz==1) println("\tAll characters are unique");
else // counts is (char,count, char,count, ...)
println("\tDuplicate... | Give a code snippet in #zkl
Task
Given a character string (which may be empty, or have a length of zero characters):
create a function/procedure/routine to:
determine if all the characters in the string are unique
indicate if or which character is duplicated and where
display each string and its length... | 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... | #DWScript | DWScript | type
Animal = class(TObject)
private
// private functions/variables
public
// public functions/variables
end;
type Dog = class(Animal) end;
type Cat = class(Animal) end;
type Collie = class(Dog) end;
type Lab = class(Dog) end; | Give a code snippet in #DWScript
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 ty... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sorting_algorithms/Insertion_sort | Sorting algorithms/Insertion 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
... | #C.23 | C# | namespace Sort {
using System;
static class InsertionSort<T> where T : IComparable {
public static void Sort(T[] entries) {
Sort(entries, 0, entries.Length - 1);
}
public static void Sort(T[] entries, Int32 first, Int32 last) {
for (var i = first + 1; i <= last; i++) {
var entry ... | Give a code snippet in #C.23
Sorting Algorithm
This is a sorting algorithm. It may be applied to a set of data in order to sort it.
For comparing various sorts, see compare sorts.
For other sorting algorithms, see sorting algorithms, or:
O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sor... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sequence_of_non-squares | Sequence of non-squares | Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A000037 in the OEIS database.
| #Eiffel | Eiffel |
class
APPLICATION
create
make
feature
make
do
sequence_of_non_squares (22)
io.new_line
sequence_of_non_squares (1000000)
end
sequence_of_non_squares (n: INTEGER)
-- Sequence of non-squares up to the n'th member.
require
n_positive: n >= 1
local
non_sq, part: ... | Give a code snippet in #Eiffel
Task
Show that the following remarkable formula gives the sequence of non-square natural numbers:
n + floor(1/2 + sqrt(n))
Print out the values for n in the range 1 to 22
Show that no squares occur for n less than one million
This is sequence A0000... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Percolation/Bond_percolation | Percolation/Bond percolation |
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean cluster density
Given an
M
×
N... | #Python | Python | from collections import namedtuple
from random import random
from pprint import pprint as pp
Grid = namedtuple('Grid', 'cell, hwall, vwall')
M, N, t = 10, 10, 100
class PercolatedException(Exception): pass
HVF = [(' .', ' _'), (':', '|'), (' ', '#')] # Horiz, vert, fill chars
def newgrid(p):
hwall = [[in... | Give a code snippet in #Python
Percolation Simulation
This is a simulation of aspects of mathematical percolation theory.
For other percolation simulations, see Category:Percolation Simulations, or:
1D finite grid simulation
Mean run density
2D finite grid simulations
Site percolation | Bond percolation | Mean clu... | 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... | #Vlang | Vlang | fn print_all(values []int) {
for i, x in values {
println("Item $i = $x")
}
} | Give a code snippet in #Vlang
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Rock-paper-scissors | Rock-paper-scissors | Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winner is decided by a set of rules:
... | #Erlang | Erlang |
-module(rps).
-compile(export_all).
play() ->
loop([1,1,1]).
loop([R,P,S]=Odds) ->
case io:fread("What is your move? (R,P,S,Q) ","~c") of
{ok,["Q"]} -> io:fwrite("Good bye!~n");
{ok,[[Human]]} when Human == $R; Human == $P; Human == $S ->
io:fwrite("Your move is ~s.~n",
... | Give a code snippet in #Erlang
Task
Implement the classic children's game Rock-paper-scissors, as well as a simple predictive AI (artificial intelligence) player.
Rock Paper Scissors is a two player game.
Each player chooses one of rock, paper or scissors, without knowing the other player's choice.
The winne... | 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
⋮
⋮
⋮
⋱
... | #Seed7 | Seed7 | $ include "seed7_05.s7i";
const type: matrix is array array integer;
const func matrix: identity (in integer: size) is func
result
var matrix: identity is matrix.value;
local
var integer: index is 0;
begin
identity := size times size times 0;
for index range 1 to size do
identity[index][... | Give a code snippet in #Seed7
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... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Short-circuit_evaluation | Short-circuit evaluation | Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable resources without side effects, an... | #OCaml | OCaml | let a r = print_endline " > function a called"; r
let b r = print_endline " > function b called"; r
let test_and b1 b2 =
Printf.printf "# testing (%b && %b)\n" b1 b2;
ignore (a b1 && b b2)
let test_or b1 b2 =
Printf.printf "# testing (%b || %b)\n" b1 b2;
ignore (a b1 || b b2)
let test_this test =
test t... | Give a code snippet in #OCaml
Control Structures
These are examples of control structures. You may also be interested in:
Conditional structures
Exceptions
Flow-control structures
Loops
Assume functions a and b return boolean values, and further, the execution of function b takes considerable res... | 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... | #Oz | Oz | declare
fun {RLEncode Xs}
for G in {Group Xs} collect:C do
{C {Length G}#G.1}
end
end
fun {RLDecode Xs}
for C#Y in Xs append:Ap do
{Ap {Replicate Y C}}
end
end
%% Helpers
%% e.g. "1122" -> ["11" "22"]
fun {Group Xs}
case Xs of nil then nil
[] X|Xr then
Ys Zs
{L... | Give a code snippet in #Oz
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 functio... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Find_the_missing_permutation | Find the missing permutation | ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
CDBA
... | #K | K | split:{1_'(&x=y)_ x:y,x}
g: ("ABCD CABD ACDB DACB BCDA ACBD ADCB CDAB DABC BCAD CADB")
g,:(" CDBA CBAD ABDC ADBC BDCA DCBA BACD BADC BDAC CBDA DBCA DCAB")
p: split[g;" "];
/ All permutations of "ABCD"
perm:{:[1<x;,/(>:'(x,x)#1,x#0)[;0,'1+_f x-1];,!x]}
p2:a@(perm(#a:"ABCD"));
/ Which permut... | Give a code snippet in #K
ABCD
CABD
ACDB
DACB
BCDA
ACBD
ADCB
CDAB
DABC
BCAD
CADB
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_subsequential_sum | Greatest subsequential sum | Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elements are negative, the result must be th... | #CoffeeScript | CoffeeScript |
max_sum_seq = (sequence) ->
# This runs in linear time.
[sum_start, sum, max_sum, max_start, max_end] = [0, 0, 0, 0, 0]
for n, i in sequence
sum += n
if sum > max_sum
max_sum = sum
max_start = sum_start
max_end = i + 1
if sum < 0 # start new sequence
sum = 0
sum_start =... | Give a code snippet in #CoffeeScript
Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elemen... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Sierpinski_carpet | Sierpinski carpet | Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ## # # ## # # #
### ###### ... | #Excel | Excel | SHOWBLOCKS
=LAMBDA(xs,
IF(0 <> xs, "█", " ")
)
SIERPCARPET
=LAMBDA(n,
APPLYN(n)(
SIERPWEAVE
)(1)
)
SIERPWEAVE
=LAMBDA(xs,
LET(
triple, REPLICATECOLS(3)(xs),
gap, LAMBDA(x, IF(x, 0, 0))(xs),
middle, APPENDCOLS(
APPENDCOLS(xs)(gap)
)(xs),
... | Give a code snippet in #Excel
Task
Produce a graphical or ASCII-art representation of a Sierpinski carpet of order N.
For example, the Sierpinski carpet of order 3 should look like this:
###########################
# ## ## ## ## ## ## ## ## #
###########################
### ###### ###### ###
# # # ##... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Interactive_programming_(repl) | Interactive programming (repl) | Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
Task
Show how to start this... | #Ring | Ring |
r = "Rosetta"
c = "Code"
s = ":"
see r+s+s+c
| Give a code snippet in #Ring
Many language implementations come with an interactive mode.
This is a command-line interpreter that reads lines from the user and evaluates these lines as statements or expressions.
An interactive mode may also be known as a command mode, a read-eval-print loop (REPL), or a shell.
... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Pernicious_numbers | Pernicious numbers | A pernicious number is a positive integer whose population count is a prime.
The population count is the number of ones in the binary representation of a non-negative integer.
Example
22 (which is 10110 in binary) has a population count of 3, which is prime, and therefore
22 is a pe... | #EchoLisp | EchoLisp |
(lib 'sequences)
(define (pernicious? n) (prime? (bit-count n)))
(define pernicious (filter pernicious? [1 .. ]))
(take pernicious 25)
→ (3 5 6 7 9 10 11 12 13 14 17 18 19 20 21 22 24 25 26 28 31 33 34 35 36)
(take (filter pernicious? [888888877 .. 888888889]) #:all)
→ (888888877 888888878 888888880 888... | Give a code snippet in #EchoLisp
A pernicious number is a positive integer whose population count is a prime.
The population count is the number of ones in the binary representation of a non-negative integer.
Example
22 (which is 10110 in binary) has a population count of 3, which is pr... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Arithmetic-geometric_mean | Arithmetic-geometric mean |
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Write a function to compute the arithmetic-geomet... | #PL.2FI | PL/I |
arithmetic_geometric_mean: /* 31 August 2012 */
procedure options (main);
declare (a, g, t) float (18);
a = 1; g = 1/sqrt(2.0q0);
put skip list ('The arithmetic-geometric mean of ' || a || ' and ' || g || ':');
do until (abs(a-g) < 1e-15*a);
t = (a + g)/2; g = sqrt(a*g);
a = t;
... | Give a code snippet in #PL.2FI
This page uses content from Wikipedia. The original article was at Arithmetic-geometric mean. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance)
Task
Write a function ... | christopher/rosetta-code | |
http://rosettacode.org/wiki/Greatest_subsequential_sum | Greatest subsequential sum | Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elements are negative, the result must be th... | #Lua | Lua | function sumt(t, start, last) return start <= last and t[start] + sumt(t, start+1, last) or 0 end
function maxsub(ary, idx)
local idx = idx or 1
if not ary[idx] then return {} end
local maxsum, last = 0, idx
for i = idx, #ary do
if sumt(ary, idx, i) > maxsum then maxsum, last = sumt(ary, idx, i), i end
en... | Give a code snippet in #Lua
Task
Given a sequence of integers, find a continuous subsequence which maximizes the sum of its elements, that is, the elements of no other single subsequence add up to a value larger than this one.
An empty subsequence is considered to have the sum of 0; thus if all elements are ne... | christopher/rosetta-code |
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