260. Single Number III

 1 class Solution {
 2 public:
 3     vector<int> singleNumber(vector<int>& nums) {
 4         int num = 0;
 5         for (const auto& item : nums) {
 6             num ^= item;
 7         }
 8         int cmp = 1, count = 0;
 9         while (!(num & cmp)) {
10             cmp <<= 1; ++count;
11         }
12         int num1 = 0;
13         for (const auto& item : nums) {
14             if (item & cmp) num1 ^= item;
15         }
16         int num2 = num ^ num1;
17         return vector<int> {num1, num2};
18     }
19 };