【一天一大 lee】字母异位词分组 (难度:中等) - Day20201214

输入: ["eat", "tea", "tan", "ate", "nat", "bat"]
输出:
[
  ["ate","eat","tea"],
  ["nat","tan"],
  ["bat"]
]

/**
 * @param {string[]} strs
 * @return {string[][]}
 */
var groupAnagrams = function(strs) {
    let map = new Map(),
        len = strs.length,
        index = 0;
    // 字符排序：字母异位词输出相同字符
    function helper(A) {
        return Array.from(A).sort().join('')
    }
    // 遍历strs，收集字母异位词
    for (let i = 0; i < len; i++) {
        const item = helper(strs[i])
        if (map.has(item)) {
            map.get(item).push(strs[i])
        }else{
             map.set(item,[strs[i]])
        }
    }
    return [...map.values()]
}