leetcode_find_all_numbers_disappeared_in_an_array

class Solution {
public:
    vector<int> findDisappearedNumbers(vector<int>& nums) {
        int maximum = nums.size();
        vector<int> ret (maximum,0);
        for(int i = 0; i < nums.size();i++)
        {
            ret[nums[i]-1] = 1;
        }
        for(int i = 0; i < maximum; i++)
        {
            if(ret[i] == 0)
                ret.push_back(i+1);
        }
        ret.erase(ret.begin(),ret.begin()+maximum);
        return ret;
    }
};