[LeetCode] Group Anagrams

문제

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.

예제

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"]]

조건

• 1 <= strs.length <= $10^4$
• 0 <= strs[i].length <= 100
• strs[i] consists of lower-case English letters.

답

풀이 1

정렬했을 때 같은 값을 갖게 되도록 해야한다. 따라서 정렬 후, join을 사용해서 나온 값을 key로 하고 해당 word를 value로 한다.

class Solution:
    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
        anagrams = collections.defaultdict(list)
        
        for word in strs:
            anagrams[''.join(sorted(word))].append(word)
            
        answer = []
        return list(anagrams.values())