Group Anagrams using Javascript

Given an array of strings strs, group the anagrams together.

Anagram: 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.

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

Note: All inputs will be in lower-case.

Using hashmap

To solve this we will use Hash Table , where each key is sorted string and each value is the list of strings from the initial input that when sorted, are equal to key.

Time Complexity Analysis

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

Space Complexity: O(N*K), the total information content stored in ans

Solution using Javascript:

const groupAnagrams = function (strs) {
  const hash = {};
 
  for (let i = 0; i < strs.length; i += 1) {
    const str = strs[i];
    const key = sortStr(str);
    console.log(key);
    hash[key] = hash[key] || [];
    hash[key].push(str);
  }
  let result = [];
  for (const i in hash) {
    result.push(hash[i]);
  }
 
  return result;
};
 
 

const sortStr = (str) => {
    const arr = str.split('');
    arr.sort((a,b) => a > b ? 1 : -1);
    return arr.join('');
}