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sieve of eratosthenes

PHP

<?php
// written by Darren Kirby


$x = $argv[1];
$y = floor(sqrt($x));
$primes = array();
$set = range(2, $x);

while ($set[0] < $y) {
    $primes[] = $set[0];
    $temp =  array_slice($set, 1);
    foreach ($temp as $i) {
        if ($i % $set[0] == 0) {
            unset($set[array_search($i, $set)]);
        }
    }
    array_shift($set); 
} 

foreach ($set as $i)
    $primes[] = $i;

foreach ($primes as $n)
    echo "$n ";

?>

back to Eratosthenes page

stats

It is Saturday May 17, 2008 11:03 am
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This page last modified: April 14, 2008 11:28 am
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