49_group_anagrams.cpp

auto init = []() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    return 0;
}();

class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        unordered_map<string, vector<string>> groups;
        for (auto& str : strs) {
            string key = str;
            sort(key.begin(), key.end());
            groups[key].push_back(str);
        }
        vector<vector<string>> result;
        for (auto& pair : groups)
            result.push_back(pair.second);
        return result;
    }
};