Group Anagrams

Problem Statement

Given an array of strings strs, group all anagrams together into sublists. You may return the output in any order.

An anagram is a string that contains the exact same characters as another string, but the order of the characters can be different.

Examples

Example 1

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

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

Example 2

Input: strs = [""]

Output: [[""]]

Example 3

Input: strs = ["a"]

Output: [["a"]]

Constraints

• 1 <= strs.length <= 10^4
• 0 <= strs[i].length <= 1000
• All strings consist of lowercase English letters.

Hints

1. Count the frequency of letters in each string and use it as a key in a hash map.
2. Sort the letters in each string to use as a key in a hash map.

Notes

• All inputs will be in lowercase.
• The order of your output groups does not matter.
• If a string has all unique characters, it will be in its own group.