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LeetCode 49 Group Anagrams - Medium

Given an array of strings, group anagrams together.

·1 min read·#LeetCode#Medium#Python

49. Group Anagrams — Medium

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Problem

Given an array of strings, group anagrams together.

Example:

Input: ["eat", "tea", "tan", "ate", "nat", "bat"], Output: [ ["ate","eat","tea"], ["nat","tan"], ["bat"] ] Note:

All inputs will be in lowercase. The order of your output does not matter.

Solution

class Solution:
    def groupAnagrams(self, strs):
        
    ### Solutioin 1
        ans = collections.defaultdict(list)
        for s in strs:
            ans[tuple(sorted(s))].append(s)
        return ans.values()
    
            
    ### Solution 2
#         ans = collections.defaultdict(list)
#         for s in strs:
#             count = [0] * 26
#             for c in s:
#                 count[ord(c) - ord('a')] += 1
#             ans[tuple(count)].append(s)
#         return ans.values()
 
 
### 此题的一大亮点是利用 tuple 当 hash 的 key， 或者是利用 ord 来组成对字母count的tuple 来当作 key。

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