LeetCode 136. Single Number C++

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?

Example 1:

Input: [2,2,1]
Output: 1

Example 2:

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





巧用位操作
0 ^ n = n
n ^ n = 0
因为题目说明只有一个数出现一次,其余都出现两次,出现两次的数异或以后为0,0与出现一次的数n异或为n
class Solution {
public:
    int singleNumber(vector<int>& nums) {
        int s = 0;
        for(int c : nums)
            s  ^= c;
        return s;
        
    }
};

 



posted @ 2019-09-23 11:17  3/8  阅读(105)  评论(0编辑  收藏  举报