剑指 Offer 53 - II. 0～n-1中缺失的数字

力扣

```java
class Solution {
    public int missingNumber(int[] nums) {
        int left = 0;
        int right = nums.length - 1;
        while (left <= right) {
            int mid = left + (right - left)/2;
            if (nums[mid] < mid) {
                left = mid + 1;
            } else if (nums[mid] > mid) {
                right = mid - 1;
            } else if (nums[mid] == mid) {
                left = mid + 1;
            }
        }
        return left;
    }
}

/*
[0,1,3]

1

mid + 1
*/
```ja