LeetCode OJ：Group Anagrams（同字符字符群）

Given an array of strings, group anagrams together.

For example, given: ["eat", "tea", "tan", "ate", "nat", "bat"], 
Return:

[
  ["ate", "eat","tea"],
  ["nat","tan"],
  ["bat"]
]

找出同字母的字符群，比较简单的方法就是用map实现，将每个字符排下序作为key就可以了，代码如下：

class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        vector<vector<string>> ret;
        map<string, vector<string>> res;
        string tmp;
        for(int i = 0; i < strs.size(); ++i){
            tmp = strs[i];  //这里是关键
            sort(tmp.begin(), tmp.end());
            res[tmp].push_back(strs[i]);
        }
        vector<string> tmpVec;
        for(typename map<string, vector<string>>::iterator it = res.begin(); it != res.end(); ++it){
            sort(it->second.begin(), it->second.end());
        }
        for(typename map<string, vector<string>>::iterator it = res.begin(); it != res.end(); ++it){
            tmpVec.clear();
            if(it->second.size() >= 1)
                for(int i = 0; i < it->second.size(); i++){
                    tmpVec.push_back(it->second[i]);
                }
            ret.push_back(tmpVec);
        }
        return ret;
    }
};

还有很多种实现方法实际上，以后再来一一实现