题解 | 查找兄弟单词

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

// 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
            // int a = in.nextInt();
            // int b = in.nextInt();
            // System.out.println(a + b);
            int n = in.nextInt();
            String[] arr = new String[n];
            for (int i = 0; i < n; i++) {
                arr[i] = in.next();
            }
            String x = in.next();
            int k = in.nextInt();
            HashMap<Character, Integer> xMap = getCharMap(x);

            ArrayList<String> broList = new ArrayList<>();
            for (String s : arr) {
                if (isBro(s, x, xMap)) {
                    broList.add(s);
                }
            }

            System.out.println(broList.size());
            if (broList.size() >= k) {
                broList.sort((s1, s2) -> {
                    for (int i = 0; i < s1.length(); i++) {
                        if (s1.charAt(i) != s2.charAt(i)) {
                            return s1.charAt(i) - s2.charAt(i);
                        }
                    }
                    return 0;
                });
                
                System.out.println(broList.get(k - 1));
            }
        }
    }

    private static boolean isBro(String s, String x,
                                 HashMap<Character, Integer> xMap) {
        if (x.length() != s.length()) {
            return false;
        }
        if (x.equals(s)) {
            return false;
        }

        HashMap<Character, Integer> sMap = getCharMap(s);
        for (char k : xMap.keySet()) {
            if (!xMap.get(k).equals(sMap.get(k))) {
                return false;
            }
        }

        return true;
    }

    private static HashMap<Character, Integer> getCharMap(String s) {
        HashMap<Character, Integer> map = new HashMap<>();
        for (char c : s.toCharArray()) {
            map.put(c, map.getOrDefault(c, 0) + 1);
        }
        return map;
    }
}