Problem Description

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.

Examples

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"]]

Constraints:

• 1 <= strs.length <= $10^4$
• 0 <= strs[i].length <= 100
• strs[i] consists of lowercase English letters.

解析

給定一個字串陣列 strs,

定義一個字串 s 的 anagram t 就是把原本的 s 的字元做重新排列產生的字串

字串 t 如果是字串 s 的 anagram 代表

t 與 s 的每個字元出現頻率相同