题解 | #查找兄弟单词#

import java.util.*;
import java.util.stream.Stream;

// 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 scanner = new Scanner(System.in);
        scanner.useDelimiter("\n");

        while (scanner.hasNext()) {
            String next = scanner.next();
            String[] S = next.split(" ");
            int num = Integer.parseInt(S[0]);
            int k = Integer.parseInt(S[S.length-1]);
            String target = S[S.length-2];

            ArrayList<String> arrayList = new ArrayList<>();
            for (int i = 1; i < S.length-2; i++) {
                if (S[i].length() != target.length() || target.equals(S[i])) {
                    continue;
                }

                if (is(target, S[i])) {
                    arrayList.add(S[i]);
                }
            }
            System.out.println(arrayList.size());
            Stream<String> sorted = arrayList.stream().sorted(new Comparator<String>() {
                @Override
                public int compare(String o1, String o2) {
                    return o1.compareTo(o2);
                }
            });
            Object[] objects = sorted.toArray();
            System.out.println(k<=arrayList.size()?objects[k-1]:"");
        }
    }

    public static boolean is(String S1, String S2) {
        char[] chars1 = S1.toCharArray();

        for (int i = 0; i < chars1.length; i++) {
            if (S2.contains(chars1[i] + "")) {
                S2 = S2.replaceFirst(chars1[i] + "", "");
            } else {
                return false;
            }
        }
        return true;
    }
}