PHP 二分查找算法实现：在指定区间内查找数字

= $low) { $mid = floor(($low + $high) / 2); if ($arr[$mid] == $x) return $mid; if ($arr[$mid] > $x) return binarySearch($arr, $low, $mid - 1, $x); return binarySearch($arr, $mid + 1, $high, $x); } return -1; } $arr = array(2, 3, 4, 10, 40); $n = count($arr); $x = 10; $result = binarySearch($arr, 0, $n - 1, $x); if ($result == -1) echo 'Element is not present in array'; else echo 'Element is present at index ', $result; ?>