题解 | #查找兄弟单词#

引入HashMap 判断是否也是兄弟字符串

import java.util.Scanner;
import java.util.Map;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;
import java.util.Comparator;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNext()) { // 注意 while 处理多个 case
            String[] strArray = in.nextLine().split(" ");
            int count = Integer.parseInt(strArray[0]);
            String[] brotherWord = new String[count];
            for (int i = 1; i < count + 1; i++) {
                brotherWord [i - 1] = strArray[i];
            }
            String word = strArray[count + 1];
            int index = Integer.parseInt(strArray[count + 2]);
            findBrotherWord(brotherWord, word, index);
        }
    }
    public static void findBrotherWord(String[] brotherWord, String word, int index) {
        List<String> list = new ArrayList<>();
        Map<Character, Integer> map = new HashMap<>();
        for (int i = 0; i < word.length(); i++) {
            map.put(word.charAt(i), map.getOrDefault(word.charAt(i), 0) + 1);
        }
        for (String tt : brotherWord) {
            if (isBrother(tt, word, map)) list.add(tt);
        }
        list.sort(new Comparator<String>() {
            @Override
            public int compare(String o1, String o2) {
                return o1.compareTo(o2);
            }
        });
        System.out.println(list.size());
        if (list.size() >= index) {
            System.out.println(list.get(index - 1));
        }
    }
    public static boolean isBrother(String str1, String str2, Map<Character, Integer> map) {
        if (str1.length() != str2.length())return false;
        if (str1.equals(str2)) return false;
        Map<Character, Integer> str1Map = new HashMap<>();
        for (int i = 0; i < str1.length(); i++) {
            str1Map.put(str1.charAt(i), str1Map.getOrDefault(str1.charAt(i), 0) + 1);
        }
        for (int i = 0; i < str1.length(); i++) {
            if (map.get(str1.charAt(i)) != str1Map.get(str1.charAt(i))) return false;
        }
        return true;
    }
}