task_url stringlengths 30 116 | task_name stringlengths 2 86 | task_description stringlengths 0 14.4k | language_url stringlengths 2 53 | language_name stringlengths 1 52 | code stringlengths 0 61.9k |
|---|---|---|---|---|---|
http://rosettacode.org/wiki/Eban_numbers | Eban numbers |
Definition
An eban number is a number that has no letter e in it when the number is spelled in English.
Or more literally, spelled numbers that contain the letter e are banned.
The American version of spelling numbers will be used here (as opposed to the British).
2,000,000,000 is two billio... | #AWK | AWK |
# syntax: GAWK -f EBAN_NUMBERS.AWK
# converted from FreeBASIC
BEGIN {
main(2,1000,1)
main(1000,4000,1)
main(2,10000,0)
main(2,100000,0)
main(2,1000000,0)
main(2,10000000,0)
main(2,100000000,0)
exit(0)
}
function main(start,stop,printable, b,count,i,m,r,t) {
printf("%d-%d:",start,s... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Factor | Factor | USING: combinators.short-circuit.smart grouping io kernel lists
lists.lazy math math.primes math.primes.factors math.statistics
prettyprint sequences sequences.deep ;
: duffinian? ( n -- ? )
{ [ prime? not ] [ dup divisors sum simple-gcd 1 = ] } && ;
: duffinians ( -- list ) 3 lfrom [ duffinian? ] lfilter ;
:... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Go | Go | package main
import (
"fmt"
"math"
"rcu"
)
func isSquare(n int) bool {
s := int(math.Sqrt(float64(n)))
return s*s == n
}
func main() {
limit := 200000 // say
d := rcu.PrimeSieve(limit-1, true)
d[1] = false
for i := 2; i < limit; i++ {
if !d[i] {
continue
... |
http://rosettacode.org/wiki/Element-wise_operations | Element-wise operations | This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponentiation
Extend the task if ... | #Excel | Excel | EVAL
=LAMBDA(s, EVALUATE(s))
matrix
={1,2,3;4,5,6;7,8,9} |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #BBC_BASIC | BBC BASIC | INPUT "Enter a variable name: " name$
INPUT "Enter a numeric value: " numeric$
dummy% = EVAL("FNassign("+name$+","+numeric$+")")
PRINT "Variable " name$ " now has the value "; EVAL(name$)
END
DEF FNassign(RETURN n, v) : n = v : = 0 |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Bracmat | Bracmat | ( put$"Enter a variable name: "
& get$:?name
& whl
' ( put$"Enter a numeric value: "
& get$:?numeric:~#
)
& !numeric:?!name
& put$(str$("Variable " !name " now has the value " !!name \n))
); |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #C.23 | C# | using System;
using System.Dynamic;
using System.Collections.Generic;
public class Program
{
public static void Main()
{
string varname = Console.ReadLine();
//Let's pretend the user has entered "foo"
dynamic expando = new ExpandoObject();
var map = expando as IDictionary<strin... |
http://rosettacode.org/wiki/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #Common_Lisp | Common Lisp |
(defun egyptian-division (dividend divisor)
(let* ((doublings (reverse (loop for n = divisor then (* 2 n)
until (> n dividend)
collect n)))
(powers-of-two (reverse (loop for n = 1 then (* 2 n)
repeat (length... |
http://rosettacode.org/wiki/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #D | D |
import std.stdio;
version(unittest) {
// empty
} else {
int main(string[] args) {
import std.conv;
if (args.length < 3) {
stderr.writeln("Usage: ", args[0], " dividend divisor");
return 1;
}
ulong dividend = to!ulong(args[1]);
ulong divisor... |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #Factor | Factor | USING: backtrack formatting fry kernel locals make math
math.functions math.ranges sequences ;
IN: rosetta-code.egyptian-fractions
: >improper ( r -- str ) >fraction "%d/%d" sprintf ;
: improper ( x y -- a b ) [ /i ] [ [ rem ] [ nip ] 2bi / ] 2bi ;
:: proper ( x y -- a b )
y x / ceiling :> d1 1 d1 / y neg x r... |
http://rosettacode.org/wiki/Eertree | Eertree | An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for the string "eertree", then outp... | #Ruby | Ruby | class Node
def initialize(length, edges = {}, suffix = 0)
@length = length
@edges = edges
@suffix = suffix
end
attr_reader :length
attr_reader :edges
attr_accessor :suffix
end
EVEN_ROOT = 0
ODD_ROOT = 1
def eertree(s)
tree = [
Node.new(0, {}, ODD_ROOT),
... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Red | Red | Red["Ethiopian multiplication"]
halve: function [n][n >> 1]
double: function [n][n << 1]
;== even? already exists
ethiopian-multiply: function [
"Returns the product of two integers using Ethiopian multiplication"
a [integer!] "The multiplicand"
b [integer!] "The multiplier"
][
result: 0
while [... |
http://rosettacode.org/wiki/Elementary_cellular_automaton | Elementary cellular automaton | An elementary cellular automaton is a one-dimensional cellular automaton where there are two possible states (labeled 0 and 1) and the rule to determine the state of a cell in the next generation depends only on the current state of the cell and its two immediate neighbors. Those three values can be encoded with three ... | #Haskell | Haskell | import Data.Array (listArray, (!), bounds, elems)
step rule a = listArray (l,r) res
where (l,r) = bounds a
res = [rule (a!r) (a!l) (a!(l+1)) ] ++
[rule (a!(i-1)) (a!i) (a!(i+1)) | i <- [l+1..r-1] ] ++
[rule (a!(r-1)) (a!r) (a!l) ]
runCA rule = iterate (step rule) |
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... | #True_BASIC | True BASIC | DEF FNfactorial(n)
LET f = 1
FOR i = 2 TO n
LET f = f*i
NEXT i
LET FNfactorial = f
END DEF
END |
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... | #x86-64_Assembly | x86-64 Assembly |
evenOdd:
mov rax,1
and rax,rdi
ret
|
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... | #XBS | XBS | #>
Typed XBS
evenOrOdd function
true = even
false = odd
<#
func evenOrOdd(a:number=0){
send a%2==0;
}
set arr:array = [0,1,2,3,4,5,6,7,9,10];
foreach(v of arr){
log(v+" is even? "+evenOrOdd(v))
} |
http://rosettacode.org/wiki/Echo_server | Echo server | Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local... | #Java | Java | import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
public class EchoServer {
p... |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Tiny_BASIC | Tiny BASIC | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Toka | Toka | bye
|
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Trith | Trith | |
http://rosettacode.org/wiki/Eban_numbers | Eban numbers |
Definition
An eban number is a number that has no letter e in it when the number is spelled in English.
Or more literally, spelled numbers that contain the letter e are banned.
The American version of spelling numbers will be used here (as opposed to the British).
2,000,000,000 is two billio... | #C | C | #include "stdio.h"
#include "stdbool.h"
#define ARRAY_LEN(a,T) (sizeof(a) / sizeof(T))
struct Interval {
int start, end;
bool print;
};
int main() {
struct Interval intervals[] = {
{2, 1000, true},
{1000, 4000, true},
{2, 10000, false},
{2, 100000, false},
{2, 1... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #J | J | sigmasum=: >:@#.~/.~&.q:
composite=: 1&< * 0 = 1&p:
duffinian=: composite * 1 = ] +. sigmasum |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Julia | Julia | using Primes
function σ(n)
f = [one(n)]
for (p,e) in factor(n)
f = reduce(vcat, [f*p^j for j in 1:e], init=f)
end
return sum(f)
end
isDuffinian(n) = !isprime(n) && gcd(n, σ(n)) == 1
function testDuffinians()
println("First 50 Duffinian numbers:")
foreach(p -> print(rpad(p[2], 4), p... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Mathematica.2FWolfram_Language | Mathematica/Wolfram Language | ClearAll[DuffianQ]
DuffianQ[n_Integer] := CompositeQ[n] \[And] CoprimeQ[DivisorSigma[1, n], n]
dns = Select[DuffianQ][Range[1000000]];
Take[dns, UpTo[50]]
triplets = ToString[dns[[#]]] <> "\[LongDash]" <> ToString[dns[[# + 2]]] & /@ SequencePosition[Differences[dns], {1, 1}][[All, 1]]
Multicolumn[triplets, {Automatic, ... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Perl | Perl | use strict;
use warnings;
use feature <say state>;
use List::Util 'max';
use ntheory qw<divisor_sum is_prime gcd>;
sub table { my $t = shift() * (my $c = 1 + max map {length} @_); ( sprintf( ('%'.$c.'s')x@_, @_) ) =~ s/.{1,$t}\K/\n/gr }
sub duffinian {
my($n) = @_;
state $c = 1; state @D;
do { push @D, ... |
http://rosettacode.org/wiki/Element-wise_operations | Element-wise operations | This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponentiation
Extend the task if ... | #Factor | Factor | USING: combinators.extras formatting kernel math.functions
math.matrices math.vectors prettyprint sequences ;
: show ( a b words -- )
[
3dup execute( x x -- x ) [ unparse ] dip
"%u %u %s = %u\n" printf
] 2with each ; inline
: m^n ( m n -- m ) [ ^ ] curry matrix-map ;
: m^ ( m m -- m ) [ v^ ... |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Clojure | Clojure | (eval `(def ~(symbol (read)) 42)) |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Common_Lisp | Common Lisp |
(setq var-name (read)) ; reads a name into var-name
(set var-name 1) ; assigns the value 1 to a variable named as entered by the user
|
http://rosettacode.org/wiki/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #Delphi | Delphi |
program Egyptian_division;
{$APPTYPE CONSOLE}
uses
System.SysUtils,
System.Math,
System.Console; //https://github.com/JensBorrisholt/DelphiConsole
type
TIntegerDynArray = TArray<Integer>;
TIntegerDynArrayHelper = record helper for TIntegerDynArray
public
procedure Add(value: Integer);
end;
... |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #FreeBASIC | FreeBASIC | ' version 16-01-2017
' compile with: fbc -s console
#Define max 30
#Include Once "gmp.bi"
Dim Shared As Mpz_ptr num(max), den(max)
Function Egyptian_fraction(fraction As String, ByRef whole As Integer, range As Integer = 0) As Integer
If InStr(fraction,"/") = 0 Then
Print "Not a fraction, program ... |
http://rosettacode.org/wiki/Eertree | Eertree | An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for the string "eertree", then outp... | #Visual_Basic_.NET | Visual Basic .NET | Module Module1
Class Node
Public Sub New(Len As Integer)
Length = Len
Edges = New Dictionary(Of Char, Integer)
End Sub
Public Sub New(len As Integer, edg As Dictionary(Of Char, Integer), suf As Integer)
Length = len
Edges = If(IsNothing(edg... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Relation | Relation |
function half(x)
set result = floor(x/2)
end function
function double(x)
set result = 2*x
end function
function even(x)
set result = (x/2 > floor(x/2))
end function
program ethiopian_mul(a,b)
relation first, second
while a >= 1
insert a, b
set a = half(a)
set b = double(b)
end while
extend third = even(first) *... |
http://rosettacode.org/wiki/Elementary_cellular_automaton | Elementary cellular automaton | An elementary cellular automaton is a one-dimensional cellular automaton where there are two possible states (labeled 0 and 1) and the rule to determine the state of a cell in the next generation depends only on the current state of the cell and its two immediate neighbors. Those three values can be encoded with three ... | #J | J | next=: ((8$2) #: [) {~ 2 #. 1 - [: |: |.~"1 0&_1 0 1@]
' *'{~90 next^:(i.9) 0 0 0 0 0 0 1 0 0 0 0 0
*
* *
* *
* * * *
* *
* * * *
* *
* * * *
* * |
http://rosettacode.org/wiki/Elementary_cellular_automaton | Elementary cellular automaton | An elementary cellular automaton is a one-dimensional cellular automaton where there are two possible states (labeled 0 and 1) and the rule to determine the state of a cell in the next generation depends only on the current state of the cell and its two immediate neighbors. Those three values can be encoded with three ... | #Java | Java | import java.awt.*;
import java.awt.event.ActionEvent;
import javax.swing.*;
import javax.swing.Timer;
public class WolframCA extends JPanel {
final int[] ruleSet = {30, 45, 50, 57, 62, 70, 73, 75, 86, 89, 90, 99,
101, 105, 109, 110, 124, 129, 133, 135, 137, 139, 141, 164,170, 232};
byte[][] cells;
... |
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... | #TUSCRIPT | TUSCRIPT | $$ MODE TUSCRIPT
LOOP num=-1,12
IF (num==0,1) THEN
f=1
ELSEIF (num<0) THEN
PRINT num," is negative number"
CYCLE
ELSE
f=VALUE(num)
LOOP n=#num,2,-1
f=f*(n-1)
ENDLOOP
ENDIF
formatnum=CENTER(num,+2," ")
PRINT "factorial of ",formatnum," = ",f
ENDLOOP |
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... | #xEec | xEec |
>100 p i# jz-1 o# t h#1 ms jz2003 p >0110 h#2 r ms t h#1 ms p
jz1002 h? jz2003 p jn0110 h#10 o$ p jn100 >2003 p p h#0 h#10
h$d h$d h$o h#32 h$s h$i h#32 jn0000 >1002 p p h#0 h#10
h$n h$e h$v h$e h#32 h$s h$i h#32 >0000 o$ p jn0000 jz100
|
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... | #XLISP | XLISP | (defun my-evenp (x)
(= (logand x 1) 0) )
(defun my-oddp (x)
(/= (logand x 1) 0) ) |
http://rosettacode.org/wiki/Echo_server | Echo server | Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local... | #JavaScript | JavaScript | const net = require('net');
function handleClient(conn) {
console.log('Connection from ' + conn.remoteAddress + ' on port ' + conn.remotePort);
conn.setEncoding('utf-8');
let buffer = '';
function handleData(data) {
for (let i = 0; i < data.length; i++) {
const char = data.ch... |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #True_BASIC | True BASIC | END |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #TUSCRIPT | TUSCRIPT | $$ MODE TUSCRIPT |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #UNIX_Shell | UNIX Shell | #!/bin/sh |
http://rosettacode.org/wiki/Eban_numbers | Eban numbers |
Definition
An eban number is a number that has no letter e in it when the number is spelled in English.
Or more literally, spelled numbers that contain the letter e are banned.
The American version of spelling numbers will be used here (as opposed to the British).
2,000,000,000 is two billio... | #C.23 | C# | using System;
namespace EbanNumbers {
struct Interval {
public int start, end;
public bool print;
public Interval(int start, int end, bool print) {
this.start = start;
this.end = end;
this.print = print;
}
}
class Program {
st... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Phix | Phix | with javascript_semantics
sequence duffinian = {false}
integer n = 2, count = 0, triplet = 0, triple_count = 0
while triple_count<50 do
bool bDuff = not is_prime(n) and gcd(n,sum(factors(n,1)))=1
duffinian &= bDuff
if bDuff then
count += 1
if count=50 then
sequence s50 = apply(tr... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Raku | Raku | use Prime::Factor;
my @duffinians = lazy (3..*).hyper.grep: { !.is-prime && $_ gcd .&divisors.sum == 1 };
put "First 50 Duffinian numbers:\n" ~
@duffinians[^50].batch(10)».fmt("%3d").join: "\n";
put "\nFirst 40 Duffinian triplets:\n" ~
((^∞).grep: -> $n { (@duffinians[$n] + 1 == @duffinians[$n + 1]) && (@duff... |
http://rosettacode.org/wiki/Element-wise_operations | Element-wise operations | This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponentiation
Extend the task if ... | #Fortran | Fortran |
program element_operations
implicit none
real(kind=4), dimension(3,3) :: a,b
integer :: i
a=reshape([(i,i=1,9)],shape(a))
print*,'addition'
b=a+a
call print_arr(b)
print*,'multiplication'
b=a*a
call print_arr(b)
print*,'division'
b=a/b
call print_arr(b)
print*,'exponentiation'
... |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #D.C3.A9j.C3.A0_Vu | Déjà Vu | local :var-name !run-blob !compile-string dup concat( ":" !prompt "Enter a variable name: " )
local var-name 42
#Assuming the user types THISISWEIRD, otherwise this'll error
!. THISISWEIRD |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #E | E | def makeNounExpr := <elang:evm.makeNounExpr>
def dynVarName(name) {
def variable := makeNounExpr(null, name, null)
return e`{
def a := 1
def b := 2
def c := 3
{
def $variable := "BOO!"
[a, b, c]
}
}`.eval(safeScope)
}
? dynVarName("... |
http://rosettacode.org/wiki/Draw_a_pixel | Draw a pixel | Task
Create a window and draw a pixel in it, subject to the following:
the window is 320 x 240
the color of the pixel must be red (255,0,0)
the position of the pixel is x = 100, y = 100 | #Action.21 | Action! | PROC Main()
BYTE
CH=$02FC, ;Internal hardware value for last key pressed
PALNTSC=$D014 ;To check if PAL or NTSC system is used
Graphics(8+16) ;Graphics 320x192 with 2 luminances
IF PALNTSC=15 THEN
SetColor(1,4,6) ;Red color for NTSC
SetColor(2,4,15)
ELSE
SetColor(1,2,6) ;Red color for PAL
... |
http://rosettacode.org/wiki/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #Erlang | Erlang | -module(egypt).
-export([ediv/2]).
ediv(A, B) ->
{Twos, Ds} = genpowers(A, [1], [B]),
{Quot, C} = accumulate(A, Twos, Ds),
{Quot, abs(C - A)}.
genpowers(A, [_|Ts], [D|Ds]) when D > A -> {Ts, Ds};
genpowers(A, [T|_] = Twos, [D|_] = Ds) -> genpowers(A, [2*T|Twos], [D*2|Ds]).
accumulate(N, Twos, Ds) ->... |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #Frink | Frink |
frac[p, q] :=
{
a = makeArray[[0]]
if p > q
{
a.push[floor[p / q]]
p = p mod q
}
while p > 1
{
d = ceil[q / p]
a.push[1/d]
[p, q] = [-q mod p, d q]
}
if p == 1
a.push[1/q]
a
}
showApproximations[false]
egypt[p, q] := join[" + ", f... |
http://rosettacode.org/wiki/Eertree | Eertree | An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for the string "eertree", then outp... | #Wren | Wren | class Node {
construct new() {
_edges = {} // edges (or forward links)
_link = null // suffix link (backward links)
_len = 0 // the length of the node
}
edges { _edges }
link { _link }
link=(l) { _link = l }
len { _len }
len=(l) { _len = l }
... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #REXX | REXX | /*REXX program multiplies two integers by the Ethiopian (or Russian peasant) method. */
numeric digits 3000 /*handle some gihugeic integers. */
parse arg a b . /*get two numbers from the command line*/
say 'a=' a ... |
http://rosettacode.org/wiki/Elementary_cellular_automaton | Elementary cellular automaton | An elementary cellular automaton is a one-dimensional cellular automaton where there are two possible states (labeled 0 and 1) and the rule to determine the state of a cell in the next generation depends only on the current state of the cell and its two immediate neighbors. Those three values can be encoded with three ... | #JavaScript | JavaScript | const alive = '#';
const dead = '.';
// ------------------------------------------------------------[ Bit banging ]--
const setBitAt = (val, idx) => BigInt(val) | (1n << BigInt(idx));
const clearBitAt = (val, idx) => BigInt(val) & ~(1n << BigInt(idx));
const getBitAt = val => idx => (BigInt(val) >> BigInt(idx)) & 1n;... |
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... | #TXR | TXR | $ txr -p '(n-perm-k 10 10)'
3628800 |
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... | #Xojo | Xojo |
For num As Integer = 1 To 5
If num Mod 2 = 0 Then
MsgBox(Str(num) + " is even.")
Else
MsgBox(Str(num) + " is odd.")
End If
Next
|
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... | #XPL0 | XPL0 | include c:\cxpl\codes;
int I;
[for I:= -4 to +3 do
[IntOut(0, I);
Text(0, if I&1 then " is odd " else " is even ");
Text(0, if rem(I/2)#0 then "odd" else "even");
CrLf(0);
];
] |
http://rosettacode.org/wiki/Echo_server | Echo server | Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local... | #Julia | Julia |
using Sockets # for version 1.0
println("Echo server on port 12321")
try
server = listen(12321)
instance = 0
while true
sock = accept(server)
instance += 1
socklabel = "$(getsockname(sock)) number $instance"
@async begin
println("Server connected to socket $soc... |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Unlambda | Unlambda | i
|
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Ursa | Ursa | |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Vala | Vala | void main() {} |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #VAX_Assembly | VAX Assembly | 0000 0000 1 .entry main,0 ;register save mask
04 0002 2 ret ;return from main procedure
0003 3 .end main ;start address for linker |
http://rosettacode.org/wiki/Eban_numbers | Eban numbers |
Definition
An eban number is a number that has no letter e in it when the number is spelled in English.
Or more literally, spelled numbers that contain the letter e are banned.
The American version of spelling numbers will be used here (as opposed to the British).
2,000,000,000 is two billio... | #C.2B.2B | C++ | #include <iostream>
struct Interval {
int start, end;
bool print;
};
int main() {
Interval intervals[] = {
{2, 1000, true},
{1000, 4000, true},
{2, 10000, false},
{2, 100000, false},
{2, 1000000, false},
{2, 10000000, false},
{2, 100000000, false},... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Sidef | Sidef | func is_duffinian(n) {
n.is_composite && n.is_coprime(n.sigma)
}
say "First 50 Duffinian numbers:"
say 50.by(is_duffinian)
say "\nFirst 15 Duffinian triplets:"
15.by{|n| ^3 -> all {|k| is_duffinian(n+k) } }.each {|n|
printf("(%s, %s, %s)\n", n, n+1, n+2)
} |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #Wren | Wren | import "./math" for Int, Nums
import "./seq" for Lst
import "./fmt" for Fmt
var limit = 200000 // say
var d = Int.primeSieve(limit-1, false)
d[1] = false
for (i in 2...limit) {
if (!d[i]) continue
if (i % 2 == 0 && !Int.isSquare(i) && !Int.isSquare(i/2)) {
d[i] = false
continue
}
var ... |
http://rosettacode.org/wiki/Element-wise_operations | Element-wise operations | This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponentiation
Extend the task if ... | #FreeBASIC | FreeBASIC | Dim Shared As Double a(1,2) = {{7, 8, 7}, {4, 0, 9}}
Dim Shared As Double b(1,2) = {{4, 5, 1}, {6, 2, 1}}
Dim Shared As Double c(1,2)
Dim Shared As Double fila, columna
Dim Shared As String p
Sub list(a() As Double)
p = "["
For fila = 0 To Ubound(a,1)
p &= "["
For columna = 0 To Ubound(b,2)
... |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Delphi | Delphi | import system'dynamic;
import extensions;
class TestClass
{
object theVariables;
constructor()
{
theVariables := new DynamicStruct()
}
function()
{
auto prop := new MessageName(console.write:"Enter the variable name:".readLine());
(prop.setPropertyMessage())(theVari... |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Elena | Elena | import system'dynamic;
import extensions;
class TestClass
{
object theVariables;
constructor()
{
theVariables := new DynamicStruct()
}
function()
{
auto prop := new MessageName(console.write:"Enter the variable name:".readLine());
(prop.setPropertyMessage())(theVari... |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Emacs_Lisp | Emacs Lisp | (set (intern (read-string "Enter variable name: ")) 123) |
http://rosettacode.org/wiki/Draw_a_pixel | Draw a pixel | Task
Create a window and draw a pixel in it, subject to the following:
the window is 320 x 240
the color of the pixel must be red (255,0,0)
the position of the pixel is x = 100, y = 100 | #Ada | Ada | with SDL.Video.Windows.Makers;
with SDL.Video.Renderers.Makers;
with SDL.Events.Events;
procedure Draw_A_Pixel is
Width : constant := 320;
Height : constant := 200;
Window : SDL.Video.Windows.Window;
Renderer : SDL.Video.Renderers.Renderer;
procedure Wait is
use type SDL.Events.Event_T... |
http://rosettacode.org/wiki/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #F.23 | F# | // A function to perform Egyptian Division: Nigel Galloway August 11th., 2017
let egyptianDivision N G =
let rec fn n g = seq{yield (n,g); yield! fn (n+n) (g+g)}
Seq.foldBack (fun (n,i) (g,e)->if (i<=g) then ((g-i),(e+n)) else (g,e)) (fn 1 G |> Seq.takeWhile(fun (_,g)->g<=N)) (N,0)
|
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #F.C5.8Drmul.C3.A6 | Fōrmulæ | package main
import (
"fmt"
"math/big"
"strings"
)
var zero = new(big.Int)
var one = big.NewInt(1)
func toEgyptianRecursive(br *big.Rat, fracs []*big.Rat) []*big.Rat {
if br.Num().Cmp(zero) == 0 {
return fracs
}
iquo := new(big.Int)
irem := new(big.Int)
iquo.QuoRem(br.Denom... |
http://rosettacode.org/wiki/Eertree | Eertree | An eertree is a data structure designed for efficient processing of certain palindrome tasks, for instance counting the number of sub-palindromes in an input string.
The data structure has commonalities to both tries and suffix trees.
See links below.
Task
Construct an eertree for the string "eertree", then outp... | #zkl | zkl | class Node{
fcn init(length){
var edges=Dictionary(), # edges (or forward links). (char:Node)
link=Void, # suffix link (backward links)
sz =length; # node length.
}
}
class Eertree{
fcn init(string=Void){
var nodes=List(),
# two initial root nodes
rto=Node(-1), # odd length r... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Ring | Ring |
x = 17
y = 34
p = 0
while x != 0
if not even(x)
p += y
see "" + x + " " + " " + y + nl
else
see "" + x + " ---" + nl ok
x = halve(x)
y = double(y)
end
see " " + " ===" + nl
see " " + p
func double n return (n * 2)
func halve n return floor(n / 2)
func ... |
http://rosettacode.org/wiki/Elementary_cellular_automaton | Elementary cellular automaton | An elementary cellular automaton is a one-dimensional cellular automaton where there are two possible states (labeled 0 and 1) and the rule to determine the state of a cell in the next generation depends only on the current state of the cell and its two immediate neighbors. Those three values can be encoded with three ... | #jq | jq | # The ordinal value of the relevant states:
def states:
{"111": 1, "110": 2, "101": 3, "100": 4, "011": 5, "010": 6, "001": 7, "000": 8};
# Compute the next "state"
# input: a state ("111" or "110" ...)
# rule: the rule represented as a string of 0s and 1s
# output: the next state "0" or "1" depending on the rule
... |
http://rosettacode.org/wiki/Elementary_cellular_automaton | Elementary cellular automaton | An elementary cellular automaton is a one-dimensional cellular automaton where there are two possible states (labeled 0 and 1) and the rule to determine the state of a cell in the next generation depends only on the current state of the cell and its two immediate neighbors. Those three values can be encoded with three ... | #Julia | Julia |
const lines = 10
const start = ".........#........."
const rules = [90, 30, 14]
rule2poss(rule) = [rule & (1 << (i - 1)) != 0 for i in 1:8]
cells2bools(cells) = [cells[i] == '#' for i in 1:length(cells)]
bools2cells(bset) = prod([bset[i] ? "#" : "." for i in 1:length(bset)])
function transform(bset, ruleposs)... |
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... | #UNIX_Shell | UNIX Shell | factorial() {
set -- "$1" 1
until test "$1" -lt 2; do
set -- "`expr "$1" - 1`" "`expr "$2" \* "$1"`"
done
echo "$2"
} |
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... | #Yabasic | Yabasic | for i = -5 to 5
print i, and(i,1), mod(i,2)
next
|
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... | #Z80_Assembly | Z80 Assembly | rrca
jp nc,isEven |
http://rosettacode.org/wiki/Echo_server | Echo server | Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local... | #Kotlin | Kotlin | import java.net.ServerSocket
import java.net.Socket
fun main() {
fun handleClient(conn: Socket) {
conn.use {
val input = conn.inputStream.bufferedReader()
val output = conn.outputStream.bufferedWriter()
input.forEachLine { line ->
output.write(line)
... |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #VBA | VBA | Sub Demo()
End Sub |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #VBScript | VBScript | ' |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Verbexx | Verbexx | |
http://rosettacode.org/wiki/Eban_numbers | Eban numbers |
Definition
An eban number is a number that has no letter e in it when the number is spelled in English.
Or more literally, spelled numbers that contain the letter e are banned.
The American version of spelling numbers will be used here (as opposed to the British).
2,000,000,000 is two billio... | #CLU | CLU | eban = cluster is numbers
rep = null
% Next valid E-ban number in the range [0..999]
next = proc (n: int) returns (int) signals (no_more)
if n>=66 then signal no_more end
if n<0 then return(0) end
% advance low digit (two four six)
if (n//10=0) then n := (n/10)*10 + 2... |
http://rosettacode.org/wiki/Eban_numbers | Eban numbers |
Definition
An eban number is a number that has no letter e in it when the number is spelled in English.
Or more literally, spelled numbers that contain the letter e are banned.
The American version of spelling numbers will be used here (as opposed to the British).
2,000,000,000 is two billio... | #D | D | import std.stdio;
struct Interval {
int start, end;
bool print;
}
void main() {
Interval[] intervals = [
{2, 1_000, true},
{1_000, 4_000, true},
{2, 10_000, false},
{2, 100_000, false},
{2, 1_000_000, false},
{2, 10_000_000, false},
{2, 100_000_000... |
http://rosettacode.org/wiki/Duffinian_numbers | Duffinian numbers | A Duffinian number is a composite number k that is relatively prime to its sigma sum σ.
The sigma sum of k is the sum of the divisors of k.
E.G.
161 is a Duffinian number.
It is composite. (7 × 23)
The sigma sum 192 (1 + 7 + 23 + 161) is relatively prime to 161.
Duffinian numbers are very common.
It is not u... | #XPL0 | XPL0 | func IsPrime(N); \Return 'true' if N is prime
int N, I;
[if N <= 2 then return N = 2;
if (N&1) = 0 then \even >2\ return false;
for I:= 3 to sqrt(N) do
[if rem(N/I) = 0 then return false;
I:= I+1;
];
return true;
];
func SumDiv(Num); \Return sum of proper divisors of Num
int Num, Div, Su... |
http://rosettacode.org/wiki/Element-wise_operations | Element-wise operations | This task is similar to:
Matrix multiplication
Matrix transposition
Task
Implement basic element-wise matrix-matrix and scalar-matrix operations, which can be referred to in other, higher-order tasks.
Implement:
addition
subtraction
multiplication
division
exponentiation
Extend the task if ... | #Go | Go | package element
import (
"fmt"
"math"
)
type Matrix struct {
ele []float64
stride int
}
func MatrixFromRows(rows [][]float64) Matrix {
if len(rows) == 0 {
return Matrix{nil, 0}
}
m := Matrix{make([]float64, len(rows)*len(rows[0])), len(rows[0])}
for rx, row := range rows... |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Epoxy | Epoxy | --Add user-defined variable to the stack
const VarName: io.prompt("Input Variable Name: "),
VarValue: io.prompt("Input Variable Value: ")
debug.newvar(VarName,VarValue)
--Outputting the results
log(debug.getvar(VarName)) |
http://rosettacode.org/wiki/Dynamic_variable_names | Dynamic variable names | Task
Create a variable with a user-defined name.
The variable name should not be written in the program text, but should be taken from the user dynamically.
See also
Eval in environment is a similar task.
| #Erlang | Erlang |
-module( dynamic_variable_names ).
-export( [task/0] ).
task() ->
{ok,[Variable_name]} = io:fread( "Variable name? ", "~a" ),
Form = runtime_evaluation:form_from_string( erlang:atom_to_list(Variable_name) ++ "." ),
io:fwrite( "~p has value ~p~n", [Variable_name, runtime_evaluation:evaluate_form(Form, ... |
http://rosettacode.org/wiki/Draw_a_pixel | Draw a pixel | Task
Create a window and draw a pixel in it, subject to the following:
the window is 320 x 240
the color of the pixel must be red (255,0,0)
the position of the pixel is x = 100, y = 100 | #ARM_Assembly | ARM Assembly |
/* ARM assembly Raspberry PI */
/* program dpixel.s */
/* compile with as */
/* link with gcc and options -lX11 -L/usr/lpp/X11/lib */
/********************************************/
/*Constantes */
/********************************************/
.equ STDOUT, ... |
http://rosettacode.org/wiki/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #Factor | Factor | USING: assocs combinators formatting kernel make math sequences ;
IN: rosetta-code.egyptian-division
: table ( dividend divisor -- table )
[ [ 2dup >= ] [ dup , 2 * ] while ] { } make 2nip
dup length <iota> [ 2^ ] map zip <reversed> ;
: accum ( a b dividend -- c )
[ 2dup [ first ] bi@ + ] dip < [ [ + ] ... |
http://rosettacode.org/wiki/Egyptian_division | Egyptian division | Egyptian division is a method of dividing integers using addition and
doubling that is similar to the algorithm of Ethiopian multiplication
Algorithm:
Given two numbers where the dividend is to be divided by the divisor:
Start the construction of a table of two columns: powers_of_2, and doublings; by a first row of... | #Forth | Forth |
variable tab-end
: build ( m n -- )
pad tab-end !
swap >r 1 swap \ dividend on ret stack
begin dup r@ <= while
2dup tab-end @ 2!
[ 2 cells ] literal tab-end +!
swap dup +
swap dup +
repeat 2drop rdrop ;
: e/mod ( m n -- q r )
over >r build
0 r> \ initial ... |
http://rosettacode.org/wiki/Egyptian_fractions | Egyptian fractions | An Egyptian fraction is the sum of distinct unit fractions such as:
1
2
+
1
3
+
1
16
(
=
43
48
)
{\displaystyle {\tfrac {1}{2}}+{\tfrac {1}{3}}+{\tfrac {1}{16}}\,(={\tfrac {43}{48}})}
Each fraction in the expression has a numerator equal to 1 (unity) and a denominator that... | #Go | Go | package main
import (
"fmt"
"math/big"
"strings"
)
var zero = new(big.Int)
var one = big.NewInt(1)
func toEgyptianRecursive(br *big.Rat, fracs []*big.Rat) []*big.Rat {
if br.Num().Cmp(zero) == 0 {
return fracs
}
iquo := new(big.Int)
irem := new(big.Int)
iquo.QuoRem(br.Denom... |
http://rosettacode.org/wiki/Ethiopian_multiplication | Ethiopian multiplication | Ethiopian multiplication is a method of multiplying integers using only addition, doubling, and halving.
Method:
Take two numbers to be multiplied and write them down at the top of two columns.
In the left-hand column repeatedly halve the last number, discarding any remainders, and write the result below the last ... | #Ruby | Ruby | def halve(x) x/2 end
def double(x) x*2 end
# iterative
def ethiopian_multiply(a, b)
product = 0
while a >= 1
p [a, b, a.even? ? "STRIKE" : "KEEP"] if $DEBUG
product += b unless a.even?
a = halve(a)
b = double(b)
end
product
end
# recursive
def rec_ethiopian_multiply(a, b)
return 0 if... |
http://rosettacode.org/wiki/Elementary_cellular_automaton | Elementary cellular automaton | An elementary cellular automaton is a one-dimensional cellular automaton where there are two possible states (labeled 0 and 1) and the rule to determine the state of a cell in the next generation depends only on the current state of the cell and its two immediate neighbors. Those three values can be encoded with three ... | #Kotlin | Kotlin | // version 1.1.51
import java.util.BitSet
const val SIZE = 32
const val LINES = SIZE / 2
const val RULE = 90
fun ruleTest(x: Int) = (RULE and (1 shl (7 and x))) != 0
infix fun Boolean.shl(bitCount: Int) = (if (this) 1 else 0) shl bitCount
fun Boolean.toInt() = if (this) 1 else 0
fun evolve(s: BitSet) {
... |
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... | #Ursa | Ursa | def factorial (int n)
decl int result
set result 1
decl int i
for (set i 1) (< i (+ n 1)) (inc i)
set result (* result i)
end
return result
end
|
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... | #zkl | zkl | [-3..4].pump(fcn(n){ println(n," is ",n.isEven and "even" or "odd") }) |
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... | #Zoea | Zoea |
program: even_or_odd
case: 1
input: 2
output: even
case: 2
input: 4
output: even
case: 3
input: 1
output: odd
case: 4
input: 7
output: odd
|
http://rosettacode.org/wiki/Echo_server | Echo server | Create a network service that sits on TCP port 12321, which accepts connections on that port, and which echoes complete lines (using a carriage-return/line-feed sequence as line separator) back to clients. No error handling is required. For the purposes of testing, it is only necessary to support connections from local... | #LFE | LFE |
(defun start ()
(spawn (lambda ()
(let ((`#(ok ,socket) (gen_tcp:listen 12321 `(#(packet line)))))
(echo-loop socket)))))
(defun echo-loop (socket)
(let* ((`#(ok ,conn) (gen_tcp:accept socket))
(handler (spawn (lambda () (handle conn)))))
(lfe_io:format "Got connection: ~p~n... |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #Verilog | Verilog | module main;
endmodule |
http://rosettacode.org/wiki/Empty_program | Empty program | Task
Create the simplest possible program that is still considered "correct."
| #VHDL | VHDL | entity dummy is
end;
architecture empty of dummy is
begin
end; |
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