题解 | #数据分类处理#

import java.util.*;
import java.util.function.*;

// 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.hasNextLine()) { // 注意 while 处理多个 case
            String ri = in.nextLine();
            String r = in.nextLine();
            String[] rs = r.split(" ");
            String[] ris = ri.split(" ");
            Set<Integer> treeSet = new TreeSet();
            for (int i = 1; i < rs.length; i++) {
                treeSet.add(Integer.parseInt(rs[i]));
            }
            StringBuilder sb = new StringBuilder();

            int count = 0;
            String tempStr = "";
            for (Integer o : treeSet) {
                for (int i = 1; i < ris.length; i++) {
                    if (ris[i].contains(o + "")) {
                        count++;
                        tempStr = tempStr + (i - 1) + " " + ris[i] + " ";
                    }
                }

                if (count > 0) {
                    tempStr = o + " " + count + " " + tempStr;
                }
                sb.append(tempStr);
                count = 0;//复位，重新统计
                tempStr = "";
            }
            int len = sb.toString().split(" ").length;
            System.out.println(len + " " + sb.toString());
        }
    }
}