268-MissingNumber.md

class Solution 
{
public:
    int missingNumber(vector<int>& nums) 
    {
        sort(nums.begin(), nums.end());
        for (int i = 0; i < nums.size(); i++)
        {
            if (nums[i] != i)
            {
                return i;
            }
        }
        return (int)nums.size();
    }
};