Anagrams

 1 class Solution {
 2 public:
 3     vector<string> anagrams(vector<string> &strs) {
 4         map<string,vector<int> > hashmap; // apply hashmap (BST)
 5         for(int i = 0; i < strs.size(); i++) {
 6             string s = strs[i];
 7             sort(s.begin(), s.end());
 8             hashmap[s].push_back(i);
 9         }
10         
11         vector<string> res;
12         for(map<string,vector<int> >::iterator it = hashmap.begin(); it != hashmap.end(); it++) {
13             vector<int>& tmp = it->second;
14             for(int i = 0; i < tmp.size(); i++) {
15                 if(tmp.size() > 1) {
16                     res.push_back(strs[tmp[i]]);
17                 }
18             }
19         }
20         return res;
21     }
22 };