字母异位词分组

1class Solution {
2public:
3    vector<vector<string>> groupAnagrams(vector<string>& strs) {
4        vector<vector<string>> result;
5        unordered_map <string,vector<string> > umap;
6        
7        for (int i = 0; i < strs.size(); i++) {
8            string tmp = strs[i];
9            sort(tmp.begin(), tmp.end());
10            umap[tmp].push_back(strs[i]);
11        }
12        
13        for (auto& collection : umap) {
14            result.push_back(collection.second);
15        }
16        return result;
17    }
18};