49. Group Anagrams

Medium (Trung bình) Python 🔗 Xem trên LeetCode

📋 Đề Bài

Given an array of strings strs, group the anagrams together. You can return the answer in any order.

An Anagram is a word or phrase formed by rearranging the letters of a different word or phrase, typically using all the original letters exactly once.

 

Example 1:

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

Example 2:

Input: strs = [""]
Output: [[""]]

Example 3:

Input: strs = ["a"]
Output: [["a"]]

 

Constraints:

  • 1 <= strs.length <= 104
  • 0 <= strs[i].length <= 100
  • strs[i] consists of lowercase English letters.

🧠 Thuật Toán & Kỹ Thuật

Hash Table (Bảng băm)Sorting (Sắp xếp)
⏱️ Thời gian O(n log n)
💾 Không gian O(n)

💻 Lời Giải

Python 0049-group-anagrams.py 
class Solution:
    def groupAnagrams(self, strs: List[str]) -> List[List[str]]:
        words = defaultdict(list)
        n = len(strs)
        
        for i in range(n):
            words[tuple(sorted(strs[i]))].append(strs[i])
            
        return list(words.values())