https://leetcode.com/problems/group-anagrams/

Source

    vector<vector<string>> groupAnagrams(vector<string>& strs)
        unordered_map<string, vstr> umapKeyAnas;

        for (int i=0; i<strs.size(); ++i) {
            /*/
            string strKey = strs[i];
            sort(begin(strKey), end(strKey));
            /*/
            map<char, int> code;
            for (auto c : strs[i]) {
                code[c]++;
            }
            string strKey;
            for (auto it=begin(code); it!=end(code); ++it) {
                strKey.push_back(it->first);
                strKey.push_back(('0'+it->second));
            }
            //*/

            if (umapKeyAnas.find(strKey) == end(umapKeyAnas)) {
                vstr vstrAnas;
                vstrAnas.push_back(strs[i]);
                umapKeyAnas.emplace(strKey, vstrAnas);
            }
            else {
                umapKeyAnas[strKey].push_back(strs[i]);
            }
        }

        vvstr vvstrAns(umapKeyAnas.size());
        int cnt = 0;
        for (auto it = begin(umapKeyAnas); it!=end(umapKeyAnas); ++it) {
            for (string strVal : it->second) {
                vvstrAns[cnt].push_back(strVal);
            }
            cnt++;
        }
        return vvstrAns;
    }

GitHub

• GroupAnagrams