题解 | #数据分类处理#

import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        while (in.hasNext()) { 
            String[] a = in.nextLine().split(" ");
            String[] b = in.nextLine().split(" ");
            LinkedList<String> I = new LinkedList<>(Arrays.asList(a));
            LinkedList<String> R = new LinkedList<>(Arrays.asList(b));
            LinkedList<String> res = new LinkedList<>();
            // 去头
            I.removeFirst();
            R.removeFirst();
            // R排序并去重
            for(int i=0;i<R.size()-1;i++){
                for(int j=i+1;j<R.size();j++){
                    if(Integer.parseInt(R.get(i))>Integer.parseInt(R.get(j))){
                        String temp = R.get(j);
                        R.set(j,R.get(i));
                        R.set(i,temp);
                    }
                }
            }
            for(int i=0;i<R.size()-1;){
                if(R.get(i).equals(R.get(i+1))){
                    R.remove(i);
                    continue;
                }else i++;
            }
            // 查询
            for(int i=0;i<R.size();i++){
                LinkedList<String> list = new LinkedList<>();
                int count=0;
                for(int j=0;j<I.size();j++){
                    if(I.get(j).indexOf(R.get(i)) != -1){
                        count++;
                        list.add(j+"");
                        list.add(I.get(j));
                    }
                }
                if(count>0){
                    list.addFirst(count+"");
                    list.addFirst(R.get(i));
                    res.addAll(list);
                }
            }
            int count = res.size();
            res.addFirst(count+"");
            for(String i : res){
                System.out.print(i+" ");
            }
        }
    }
}