Leetcode题库——49.字母异位词分组【##】

---

@author: ZZQ
@software: PyCharm
@file: leetcode49_groupAnagrams.py
@time: 2018/11/19 13:18
要求：给定一个字符串数组，将字母异位词组合在一起。字母异位词指字母相同，但排列不同的字符串。
示例:
输入: ["eat", "tea", "tan", "ate", "nat", "bat"],
输出:
[
["ate","eat","tea"],
["nat","tan"],
["bat"]
]
说明：
所有输入均为小写字母。
不考虑答案输出的顺序。
思路：ans用一个字典来表示，字典的键值是由26个字母组成的数组，来存储当前单词的哈希映射，值则是对应的这个单词。
最终的输出是ans的值。
例如：

     对于ate,其键值为【1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0】
     则在ans中，
     ans = {【1,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0】：【"ate","eat","tea"】
                【1,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,0】：【"nat","tan"】
                【1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0,0】：【"bat"】
                }

import collections


class Solution():
    def __init__(self):
        pass

    def groupAnagrams(self, strs):
        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()