【LeetCode热题100】【哈希】字母异位词分组

输入: strs = ["eat", "tea", "tan", "ate", "nat", "bat"]
输出: [["bat"],["nat","tan"],["ate","eat","tea"]]

输入: strs = [""]
输出: [[""]]

输入: strs = ["a"]
输出: [["a"]]

class Solution {
public:
    vector<vector<string>> groupAnagrams(vector<string>& strs) {
        unordered_map<string,vector<string>>hash;
        for(auto&word:strs){
            string key=word;
            sort(key.begin(),key.end());
            hash[key].push_back(word);
        }
        vector<vector<string>>answer;
        for(auto it=hash.begin();it!=hash.end();it++){
            answer.push_back(it->second);
        }
        return answer;
    }
};