17.04. Missing Number

class Solution:
    def missingNumber(self, nums: List[int]) -> int:
        res = 0
        for i, num in enumerate(nums):
            res = res ^ num ^ (i + 1)
        return res

class Solution {
    public int missingNumber(int[] nums) {
        int res = 0;
        for (int i = 0; i < nums.length; ++i) {
            res = res ^ nums[i] ^ (i + 1);
        }
        return res;
    }
}

/**
 * @param {number[]} nums
 * @return {number}
 */
var missingNumber = function (nums) {
    let res;
    for (let i = 0; i < nums.length; i++) {
        res = res ^ nums[i] ^ (i + 1);
    }
    return res;
};

class Solution {
public:
    int missingNumber(vector<int>& nums) {
        int res = 0;
        for (int i = 0; i < nums.size(); ++i) {
            res = res ^ nums[i] ^ (i + 1);
        }
        return res;
    }
};