php 二分查找算法

二分查找算法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;}