---
url: https://sugarat.top/computerBase/offer/p53-2.md
---

# 面试题53 - II. 0～n-1中缺失的数字

## 示例

```js
示例 1:

输入: [0,1,3]
输出: 2
示例 2:

输入: [0,1,2,3,4,5,6,7,9]
输出: 8
```

## JS

```js
/**
 * @param {number[]} nums
 * @return {number}
 */
var missingNumber = function (nums) {
    let left = 0, right = nums.length - 1
    while (left <= right) {
        mid = ~~((left + right) / 2)
        if (nums[mid] !== mid) {
            right = mid - 1
        } else {
            left = mid + 1
        }
    }
    return left
};
```

[题链](https://leetcode-cn.com/problems/que-shi-de-shu-zi-lcof/)