Euclidean algorithm - Find the greatest common divisor of two integers

greatest-common-divisor.php

<?php
/**
 * Returns the greatest common divisor of two integers using the Euclidean algorithm.
 *
 * @param $a
 * @param $b
 *
 * @return int
 */
function get_greatest_common_divisor( $a, $b ) {
	$large = $a > $b ? $a: $b;
	$small = $a > $b ? $b: $a;
	$remainder = $large % $small;
	return 0 == $remainder ? $small : get_greatest_common_divisor( $small, $remainder );
}