0268_Missing_Number.cpp

#pragma GCC optimize("Ofast","inline","ffast-math","unroll-loops","no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native","f16c")
class Solution {
public:
    int missingNumber(vector<int>& nums) {
        ios_base::sync_with_stdio(0), cin.tie(0), cout.tie(0);
        int sum1=nums.size();
        for(int i=0; i<nums.size(); i++){
            sum1^=(i^nums[i]);
        }
        return sum1;
    }
};