349. intersection of two arrays

class Solution {
public:
    vector<int> intersection(vector<int>& nums1, vector<int>& nums2) {
        map<int,int> mapNums;
        vector<int> nums;
        for (int i = 0; i < nums1.size(); i++) {
            mapNums.insert(make_pair(nums1[i],0));
        }
        
        for (int i = 0; i < nums2.size(); i++) {
            map<int,int>::iterator it = mapNums.find(nums2[i]);
            if (it != mapNums.end())
                it->second++;
        }
        
        for (map<int,int>::iterator it = mapNums.begin(); it != mapNums.end();it++) {
            if (it->second > 0)
                nums.push_back(it->first);
        }
        return nums;
    }
};