simplifyArray.php

<?php
function gcd($a, $b) {
    $a = abs($a);
    $b = abs($b);
    if ($a < $b) {
        $c = $a;
        $a = $b;
        $b = $c;
    }
    if ($b == 0) {
        return $a;
    }
    $r = $a % $b;
    while ($r > 0) {
        $a = $b;
        $b = $r;
        $r = $a % $b;
    }
    return $b;
}
function simplify($ar) {
    $a = null;
    foreach ($ar as $b) {
        if (is_null($a)) {
            $a = $b;
            continue;
        }
        $a = gcd($a, $b);
        if ($a <= 1) {
            return $ar;
        }
    }
    foreach ($ar as &$val) {
        $val = $val / $a;
    }
    return $ar;
}