题解 | #数据分类处理#

import java.io.*;
import java.util.Arrays;
public class Main{
    public static void main(String[] args) throws Exception{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String str;
        while((str = br.readLine()) != null){
            String[] I = str.split(" ");
            String[] tmp = br.readLine().split(" ");
            int[] R = new int[Integer.parseInt(tmp[0])];
            for(int i = 0;i < R.length;++i)
                R[i] = Integer.parseInt(tmp[i + 1]);
            R = Arrays.stream(R).distinct().sorted().toArray();
            StringBuilder res = new StringBuilder();
            int cnt = 0;
            for(int i = 0; i < R.length; ++i){
                String Ri = R[i] + "";
                int num = 0;
                StringBuilder idx = new StringBuilder();
                for(int j = 1;j < I.length;++j){
                    if(I[j].indexOf(Ri) != -1){
                        num++;
                        idx.append(" ").append(j - 1).append(" ").append(I[j]);
                    }
                }
                if(num > 0){
                    res.append(" ").append(R[i]).append(" ").append(num).append(idx);
                    cnt += num * 2 + 2;
                }
            }
            System.out.println(cnt + res.toString());
        }
    }
}