260. Single Number III

class Solution {
public:
vector<int> singleNumber(vector<int>& nums) {
int res = 0;
for(auto i : nums){
res ^= i;
}
int dif = ((res - 1) & res) ^ res;
int a = 0, b = 0;
for(auto i : nums){
if(i & dif)
a ^= i;
else
b ^= i;
}
vector<int> ans;
ans.push_back(a);
ans.push_back(b);
return ans;
}
};