实现字符串分组 [“ate”,”att”,”test”,”ttes”,”tae”] 分组结果是 [[“ate”,”tae”],[“test”,”ttes],[“att”]]

package com.company;
import java.lang.reflect.Array;
import java.util.*;
public class Test2 {
    public static void main(String[] args) {
        String[] s = {"ate","att","test","ttes","tae"};
        System.out.println(new Test2().stringGroup(s));
    }
    public List<List<String>> stringGroup(String[] strs){
        if(strs == null || strs.length == 0){
            return new ArrayList<>();
        }
        Arrays.sort(strs);
        Map<String,List<String>> map = new HashMap<>();
        for(String str : strs){
            char[] c = str.toCharArray();
            Arrays.sort(c);
            String sortedStr = String.valueOf(c);
            if(!map.containsKey(sortedStr))
                map.put(sortedStr,new ArrayList<>());
            map.get(sortedStr).add(str);
        }
        return new ArrayList<>(map.values());
    }
}

结果显示为下图：