LeetCode || Single Number

class Solution {public:    //主要思想：    //    异或满足交换律，a1 ^ a2 ^ .... ^ an ^ a1 ^ .... ^ an-1 = (a1^a1)^(a2 ^a2) ^(....) ^(an-1 ^ an-1) ^ an    //    a ^ a = 0;    //    a ^ 0 = a;    int singleNumber(vector<int>& nums) {        if(nums.size()==0)             return 0;        int result = nums[0];        for(int i = 1;i<nums.size();i++)        {            result = result ^ nums[i];        }        return result;    }};