Single Number

Posted 2020-10-29 jiadyang

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?

利用异或的性质：

 1 class Solution {
 2 public:
 3     int singleNumber(vector<int>& nums) 
 4     {
 5         int n = nums.size();
 6         int res = 0;
 7         for (int i = 0; i < n; ++i)
 8         {
 9             res ^= nums[i];
10         }
11         return res;
12     }
13 };