LeetCode 136: Single Number

Single Number

Given an array of integers, every element appears twice except for one. Find that single one.

Note:
Your algorithm should have a linear runtime complexity. Could you implement it without using extra memory?

解题思路

class Solution {public:    int singleNumber(vector<int>& nums) {        if (nums.size() == 0) return 0;        int ans = nums[0];        for (int i = 1; i < nums.size(); ++i) {            ans ^= nums[i];        }        return ans;    }};