intersection-of-two-arrays-ii

https://leetcode.com/problems/intersection-of-two-arrays-ii/

class Solution {
public:
    vector<int> intersect(vector<int>& nums1, vector<int>& nums2) {
        multiset<int> ms(nums1.begin(), nums1.end());
        vector<int> result;
        for (vector<int>::iterator itr=nums2.begin();
             itr != nums2.end();
             ++itr) {
            multiset<int>::iterator mitr = ms.find(*itr);
            if (mitr != ms.end()) {
                result.push_back(*itr);
                ms.erase(mitr);
            }
        }
        return result;
    }
};