#49 Group Anagrams——Top 100 Liked Questions-蒲公英云

#49 Group Anagrams——Top 100 Liked Questions

Given an array of strings, group anagrams together.

Example:

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

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第一次：参考官方答案，使用collections包，可直接转成如下格式：

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class Solution(object):
    def groupAnagrams(self, strs):
        """
        :type strs: List[str]
        :rtype: List[List[str]]
        """
        ans = []
        d = collections.defaultdict(list)
        for s in strs:
            d[tuple(sorted(s))].append(s)
        return d.values()
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Runtime: 84 ms, faster than 98.57% of Python online submissions for Group Anagrams.

Memory Usage: 16.3 MB, less than 31.44% of Python online submissions for Group Anagrams.

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第二次：更好理解：建立字典，key是排序后的单词，value是与排序后单词相等的原单词

“””
class Solution(object):
    def groupAnagrams(self, strs):
        """
        :type strs: List[str]
        :rtype: List[List[str]]
        """
        """
        建立字典，key是排序后的单词，value是与排序后单词相等的原单词
        """
        res = {}
        for s in strs:
            if ''.join(sorted(s)) not in res:
                res[''.join(sorted(s))] = [s]
            else:
                res[''.join(sorted(s))].append(s)
        return res.values()
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Runtime: 100 ms, faster than 81.66% of Python online submissions for Group Anagrams.

Memory Usage: 15.4 MB, less than 90.72% of Python online submissions for Group Anagrams.

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