268. Missing Number

Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.

For example,
Given nums = [0, 1, 3] return 2.

Note:
Your algorithm should run in linear runtime complexity. Could you implement it using only constant extra space complexity?

 

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