groupAnagrams.js

/*
49. Group Anagrams

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"]]
*/

/**
 * @param {string[]} strs
 * @return {string[][]}
 */
var groupAnagrams = function (strs) {
    const anagrams = new Map()
    for (const str of strs) {
        const sortedStr = str.split("").sort().join("")
        if (anagrams.has(sortedStr)) {
            anagrams.get(sortedStr).push(str)
        } else {
            anagrams.set(sortedStr, [str])
        }
    }
    return Array.from(anagrams.values())
}