49. Group Anagrams

49. Group Anagrams

0. 参考文献

序号	文献
1	[LeetCode] Group Anagrams 群组错位词

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.

2. 思路

题目的要求是把错位词都分到一类里面。错位词的定义是，比如eat是aet的错位词。就是字母一样，但是排列组合的方式不一样。解法也很简单，把，每次字符出现的频率当做key计算。相同的key就分类到同一个数组里面。

3. 实现

class Solution(object):
    def groupAnagrams(self, strs):
        """
        :type strs: List[str]
        :rtype: List[List[str]]
        """
        # 思路，每个单词的每个字符计算ascii码，如果是错位词，则ascii码的值相加肯定一样。用ascii的值做key保存结果
        ret = []
        r_map = {}
        
        for e in strs:
            tmp1 = [0]*128
            for v in e :
                tmp1[ ord(v) ] = tmp1[ ord(v) ] + 1 
            
            tmp2=""
            for e1 in tmp1:
                tmp2 = tmp2+str(e1)
            
            if  r_map.has_key(tmp2):
                r_map[tmp2].append(e)
            else:
                r_map[tmp2] = [e]
        
        for v in r_map.values():
            ret.append(v)
        return ret