leetcode 只出现一次的数字

 Given a non-empty 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?

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

 

//#include <numeric> 
class Solution {
public:
    int singleNumber(vector<int>& nums) {
        return accumulate(nums.begin(), nums.end(), 0, std::bit_xor<int>());
    }
};