题解 | #查找兄弟单词#

import java.util.*;
/**
 * 输入：
 * 6 cab ad abcd cba abc bca abc 1
 * 输出：
 * 3
 * bca
 * 说明：
 * abc的兄弟单词有cab cba bca，所以输出3
 * 经字典序排列后，变为bca cab cba，所以第1个字典序兄弟单词为bca
 */
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNextLine()) {
            String str = in.nextLine();
            // 解析输入的字符串
            String[] split = str.split(" ");
            int length = split.length;
            List<String> list = new ArrayList<>();
            List<String> brotherList = new ArrayList<>();
            int inTotal = Integer.parseInt(split[0]);
            int count = 0;
            for (String s : split) {
                if (count > 0 && count <= inTotal) {
                    list.add(s);
                }
                count++;
            }
            String letter = split[length - 2]; // 目标单词
            int order = Integer.parseInt(split[length - 1]); // 目标顺序

            // 收集兄弟单词
            for (String s : list) {
                if (isBrother(s, letter)) {
                    brotherList.add(s);
                }
            }

            System.out.println(brotherList.size()); //输出兄弟单词的数量

            // 对兄弟单词排序
            Collections.sort(brotherList);
            if (brotherList.size() >= order) {
                System.out.println(brotherList.get(order - 1));
            }

        }
    }

    /**
     * 是否是兄弟单词
     */
    private static boolean isBrother(String s, String letter) {
        if (s.equals(letter)) {
            return false;
        }
        char[] chars = s.toCharArray();
        char[] chars1 = letter.toCharArray();
        Arrays.sort(chars);
        Arrays.sort(chars1);
        return new String(chars).equals(new String(chars1));
    }

}