1. 题目说明

给定一个字符串数组，将字母异位词组合在一起。字母异位词指字母相同，但排列不同的字符串。

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

2. 解题

<?php
class Solution {

    /**
     * @param String[] $strs
     * @return String[][]
     */
    public function groupAnagrams($strs) {
        if (!$strs) return [];

        $ret = [];
        foreach ($strs as $v) {
            $tmpArr = str_split($v);
            asort($tmpArr);
            $tmpStr = implode('', $tmpArr);
            $ret[$tmpStr][] = $v;
        }
        return array_values($ret);
    }
}
$strs = ["eat", "tea", "tan", "ate", "nat", "bat"];
$cls = new Solution();
$r = $cls->groupAnagrams($strs);
array_walk($r, function (&$v) {
    $v = implode(',', $v);
});
print_r($r);