Mid-Atlantic Developer Conference


Example #1 Factorial function using GMP

function fact($x
$return 1;
    for (
$i=2$i <= $x$i++) {
$return gmp_mul($return$i);

gmp_strval(fact(1000)) . "\n";

This will calculate factorial of 1000 (pretty big number) very fast.

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User Contributed Notes 2 notes

fe at e dot com
1 year ago
If you ever need to use this, please see http://php.net/manual/en/function.gmp-fact.php
Juliano Barreto
3 years ago
I forgot to mention. You need (obviously) to remove the gmp function for a usual one. Like this:

function fact($num)
    $res = 1;
    for ($n = $num; $n >= 1; $n--)
        $res = $res*$n;
    return $res;
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