function MinDistance(&$arr, $number1, $number2) {
$size = count($arr);
$min_distance = PHP_INT_MAX;
for ($i = 0; $i < $size; $i++) {
for ($j = $i + 1; $j < $size; $j++) {
if ($arr[$i] == $number1 && $arr[$j] == $number2 ||
$arr[$i] == $number2 && $arr[$j] == $number1) {
$min_distance = min($min_distance, abs($i - $j));
}
}
}
return $min_distance;
}
$arr = array(2, 3, 7, 3, 3, 4, 8, 8, 8, 11, 9, 1, 3);
echo MinDistance($arr, 3, 8);
/*
run:
2
*/