Leetcode 49. Group Anagrams
==
### Description
(medium)
Given an array of strings strs, group the anagrams together. You can return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

#### example 1:
Input: strs = ["eat","tea","tan","ate","nat","bat"]
Output: [["bat"],["nat","tan"],["ate","eat","tea"]]
#### example 2:
Input: strs = [""]
Output: [[""]]
#### example 3:
Input: strs = ["a"]
Output: [["a"]]
### 想法
碰到這種一樣字母的又需要裝不只一個value的就可以使用dict，先存一個sorted_str作為比較，判斷使用的字母是否一樣，然後存進去dict中，若是dict中沒有這個key，就創造一個key並帶一個空list，若是有就append進去
照著這樣做就會得到一個dict:

str_dic={aet:[eat, tea, ate], ant:[tan, nat], abt:[bat]}

### 程式碼
#### python:

class Solution:
    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
        str_dic={}
        for i in strs:
            sorted_i = Solution.tostr(i)
            if sorted_i not in str_dic:
                str_dic[sorted_i]=[]
            str_dic[sorted_i].append(i)
        ans=[]
        for value in str_dic.values():
            ans.append(value)

        return ans
    def tostr(strs):
        return "".join(sorted(strs))

Runtime: 135 ms
Memory Usage: 17.2 MB
Your runtime beats 71.72 % of python3 submissions.