题解 | #查找兄弟单词#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()) {
            String line = sc.nextLine();
            String[] arr = line.split(" ");
            int length = arr.length;
            int num = Integer.parseInt(arr[0]);
            int index = Integer.parseInt(arr[length - 1]);
            String findLetter = arr[length - 2];
            ArrayList<String> list = new ArrayList<>();
            for (int i = 1; i <= num; i++) {
                String s = arr[i];
                if (s.length() != findLetter.length()) {
                    continue;
                }
                if (s.equals(findLetter)) {
                    continue;
                }
                if (!isBrother(s, findLetter)) {
                    continue;
                }
                list.add(s);
            }
            int size = list.size();
            System.out.println(size);
            if (size >= index) {
                Collections.sort(list);
                System.out.println(list.get(index - 1));
            }
        }
        sc.close();
    }

    private static boolean isBrother(String s, String findLetter) {
        char[] sChars = s.toCharArray();
        char[] fChars = findLetter.toCharArray();
        Arrays.sort(sChars);
        Arrays.sort(fChars);
        return Arrays.equals(sChars, fChars);
    }
}