Given an array of strings, group anagrams together.

Example:

Input: ["eat", "tea", "tan", "ate", "nat", "bat"],Output:[  ["ate","eat","tea"],  ["nat","tan"],  ["bat"]] 用一个hash表来存储字典序同分词，后面用一个容器接原词； 例如 ate eat tea ，字典序都是aet，后面的second为一个vector容器，承接 ate eat tea code will talk