3.13 Anagrams

Notes: Given an array of strings, return all groups of strings that are anagrams. Note: All inputs will be in lower-case.  Solution: Sort the string to see if they're anagrams. Solution 1 is simpler than 2. */

class Solution {public:    vector<string> anagrams(vector<string> &strs) {        return anagrams_1(strs);    }        // solution 1    vector<string> anagrams_1(vector<string> &strs) {        typedef map<string, vector<int> > MAP;        MAP map;        for (int i = 0; i < strs.size(); ++i)         {            string s = strs[i];            sort(s.begin(), s.end());            map[s].push_back(i);        }        vector<string> res;        MAP::iterator it = map.begin();        for (; it != map.end(); it++)         {            vector<int> &anagrams = it->second;            if (anagrams.size() > 1) {                for (int i = 0; i < anagrams.size(); ++i)                    res.push_back(strs[anagrams[i]]);            }        }        return res;    }        // solution 2    vector<string> anagrams_2(vector<string> &strs) {        typedef unordered_map<string, int > MAP;        vector<string> res;        MAP anagram;        for (int i = 0; i < strs.size(); ++i)        {            string s = strs[i];            sort(s.begin(), s.end());            MAP::iterator it = anagram.find(s);            if (it == anagram.end())             {                anagram[s] = i;            }             else             {                if (it->second >= 0) {                    res.push_back(strs[it->second]);                    it->second = -1;                }                res.push_back(strs[i]);            }        }        return res;    }};