Group Anagrams

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

LeetCode: Group Anagrams

Example:

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

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

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

Hints

Hint 1

Anagrams will have the same characters when sorted. Can you use the sorted string as a key?

Hint 2

Use a hash map where the key is the "signature" of the anagram group (like sorted string), and the value is the list of words.

Hint 3

Alternatively, you could use character counts as the key instead of sorted strings. Which is more efficient?