php二分法查找

//二分查找（数组里查找某个元素） function bin_sch($array, $low, $high, $k){ ???if ($low <= $high) { ???????$mid = intval(($low + $high) / 2); ???????if ($array[$mid] == $k) { ???????????return $mid; ???????} elseif ($k < $array[$mid]) { ???????????return bin_sch($array, $low, $mid - 1, $k); ???????} else { ???????????return bin_sch($array, $mid + 1, $high, $k); ???????} ???} ???return -1;}