"""
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.

Complexity Analysis

Time Complexity: O(NK \log K)O(NKlogK), where NN is the length of strs, and KK is the maximum length of a string in strs. The outer loop has complexity O(N)O(N) as we iterate through each string. Then, we sort each string in O(K \log K)O(KlogK) time.

Space Complexity: O(NK)O(NK), the total information content stored in ans.
"""
from collections import defaultdict
class Solution(object):
    def groupAnagrams(self, strs):
        """
        :type strs: List[str]
        :rtype: List[List[str]]
        """
        ans = defaultdict(list)
        for s in strs:
            ans[''.join(sorted(s))] += [s]
        return ans.values()
