题解 | #查找兄弟单词#

import java.util.*;

// 题意太难懂了，做了好久，思路错了好多次
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) { 
            String s = in.nextLine();
            String[] split = s.split(" ");
            int n = Integer.parseInt(split[0]);
            String[] dict = new String[n];
            for (int i = 0; i < n; i++) {
                dict[i] = split[i + 1];
            }
            String t = split[n + 1];
            int k = Integer.parseInt(split[n + 2]);
            String[] out = find(dict, t, k);
            if (null == out[1]) {
                System.out.println(out[0]);
            } else {
                System.out.println(out[0]);
                System.out.println(out[1]);
            }
        }
    }

    public static String[] find(String[] dict, String t, int k) {
        int n = dict.length;
        String[] res = new String[2];
        int[] dict1 = new int[26];
        for (int i = 0; i < t.length(); i++) {
            dict1[t.charAt(i) - 'a']++;
        }
        List<String> list = new ArrayList<>();
        for (int i = 0; i < n; i++) {
            if (!dict[i].equals(t) && t.length() == dict[i].length() && isBrother(dict1, dict[i])) {
                list.add(dict[i]);
            }
        }
        res[0] = list.size() + "";
        if (k > list.size()) {
            return res;
        }
        Collections.sort(list, (a, b) -> a.compareTo(b));
        res[1] = list.get(k - 1);
        return res;
    }

    public static boolean isBrother(int[] dict1, String b) {
        int[] dict2 = new int[26];
        for (int i = 0; i < b.length(); i++) {
            dict2[b.charAt(i) - 'a']++;
        }
        return Arrays.equals(dict1, dict2);
    }
}