10.2 Group Anagram

Simple string question.

    void groupAnagrams(vector<string>& strs, vector<string>& res) {    unordered_map<string, multiset<string>> mp;    for (string s : strs) {        string t = s;        sort(t.begin(), t.end());        mp[t].insert(s);    }    for (auto m : mp) {        for(string s : m.second){            res.push_back(s);        }    }}