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.

来源：力扣（LeetCode）
链接：https://leetcode-cn.com/problems/group-anagrams
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因为map会自动排序，所以一切都自动调整好了

把字符串sort后放入对应map，自动就排好了、，最后pushback。。

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

};