Group Anagrams

Write a function that groups all 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.

How to Solve

Use a hash map where the key is a sorted version of each string (or a character frequency signature), and the value is an array of anagrams. Iterate through the input array, sort each string to create a key, and add the original string to the corresponding group.

Code

const groupAnagrams = (strs: string[]): string[][] => {
  // Your implementation here
};

Test Cases

Input 1

const strs1 = ["eat", "tea", "tan", "ate", "nat", "bat"];

Expected Output: [["bat"], ["nat", "tan"], ["ate", "eat", "tea"]] (or any order of groups)

Input 2

const strs2 = [""];

Expected Output: [[""]]

Input 3

const strs3 = ["a"];

Expected Output: [["a"]]

Complexity

Time Complexity: O(n * k log k) - Where n is the number of strings and k is the average length. We sort each string (k log k) and iterate through n strings.

Space Complexity: O(n * k) - We store all strings in the hash map, which requires space for n strings of average length k.