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;
}
};