leetcode hot 06

合集 - leetcode hot100(25)

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收起

解题思路：需要使用hashmap，定义是（<String,List()>）遍历数组内每一个字符串，转为字符数组后用Arrays.sort()排序，如果hashmap.containsKey没有对应的key，就将排序后的字符数组转回字符串(new String(arr))，以（s_new,new List()）的形式put进入hashmap,然后将原来的字符串add如字符列表中，然后下一轮遍历。直到最后所有都放进去再用list.addAll(hashmap.values())的方式返回list。

import java.util.Arrays;
class Solution {
    public List<List<String>> groupAnagrams(String[] strs) {
        List<List<String>> list = new ArrayList<>();
        Map<String,List<String>> hashmap = new HashMap<>();
        for(String str:strs){
            char[] arr = str.toCharArray();
            Arrays.sort(arr);
            String s = new String(arr);
            if(!hashmap.containsKey(s)){
                hashmap.put(s,new ArrayList<String>());
            }
            hashmap.get(s).add(str);
        }
        list.addAll(hashmap.values());
        return list;
    }
}