540. Single Element in a Sorted Array（LeetCode）

Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element that appears only once.

Example 1:

Input: [1,1,2,3,3,4,4,8,8]
Output: 2

Example 2:

Input: [3,3,7,7,10,11,11]
Output: 10

Note: Your solution should run in O(log n) time and O(1) space.

class Solution {
public:
    int singleNonDuplicate(vector<int>& nums) {
        int len = nums.size();
        int sum = 0;
        for (int i = 0; i < len; i++)
        {
            sum ^= nums[i];
        }
        return sum;
    }
};