top145-#268

[LionCoder4ever]

• n ^ 1 ^ 1 = n

class Solution {
public:
    int missingNumber(vector<int>& nums) {
        int n = nums.size();
        int ans = n;
        for(int i=0;i<n;i++) {
            ans ^= nums[i] ^ i;
        }
        return ans;
    }
};