Single Number III

class Solution {
public:
    vector<int> singleNumber(vector<int>& nums) {
        vector<int> result;
        int a = 0;
        int b = 0;
        for(int i = 0; i < nums.size(); i++) {
            a ^= nums[i];
        }
        int index = a & ~(a - 1);
        for(int i = 0; i < nums.size(); i++) {
            if(index & nums[i]) {
                b ^= nums[i];
            }
        }
        a = a ^ b;
        result.push_back(a);
        result.push_back(b);
        return result;
    }
};