class Solution {
public:
    vector<int> findDuplicates(vector<int>& nums) {
        unordered_map<int,int> op;
        vector<int> result;
        for(auto c : nums)
        {
            if(op[c]<1)
            {
                op[c]++;
            }
            else if(op[c]>0)
            {
                result.push_back(c);
            }

        }
        return result;


    }
};