49. Group Anagrams

Given an array of strings, group anagrams together.

Example:

Input: ["eat", "tea", "tan", "ate", "nat", "bat"],
Output:
[
  ["ate","eat","tea"],
  ["nat","tan"],
  ["bat"]
]

Note:

• All inputs will be in lowercase.
• The order of your output does not matter.

 

AC code:

class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        unordered_map<string, vector<string>> mp;
        vector<vector<string>> res;
        for (auto str : strs) {
            string tage = str;
            sort(tage.begin(), tage.end());
            mp[tage].push_back(str);
        }
        for (auto m : mp) {
            sort(m.second.begin(), m.second.end());
            res.push_back(m.second);
        }
        return res;
    }
};

Runtime: 36 ms, faster than 37.09% of C++ online submissions for Group Anagrams.