LeetCode-E-Single Number

題目

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?

解法

異或

實現

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