/*
 * Given an array of strings, group anagrams together.
 *
 * Example: 
 * Input: ["eat", "tea", "tan", "ate", "nat", "bat"],
 * Output: [
 *    ["ate","eat","tea"],
 *    ["nat","tan"],
 *    ["bat"]
 * ]
 * 
 * Note: 
 * All inputs will be in lowercase.
 * The order of your output does not matter.
 *
*/
const { assert }  = require('../../util/js'); 

/**
 * @param {string[]} strs
 * @return {string[][]}
 */
const groupAnagrams = (strs) => {
    const map = {};
    strs.forEach(str => {
       const key = str.split('').sort().join('');
       if (!map[key]) {
           map[key] = [str];
       } else {
           map[key].push(str);
       }
    });
    
    return Object.values(map);
};

/* Test Case 1
 * Input: ["eat", "tea", "tan", "ate", "nat", "bat"],
 * Output: [
 *    ["ate","eat","tea"],
 *    ["nat","tan"],
 *    ["bat"]
 * ]
 */
x = [ 'eat', 'tea', 'tan', 'ate', 'nat', 'bat'];
sol = [['eat', 'tea', 'ate'], ['tan', 'nat'], ['bat']];
assert(JSON.stringify(groupAnagrams(x)) === JSON.stringify(sol), `Output: ${JSON.stringify(sol)}`);