题解 | #数据分类处理#

import java.util.*;

// 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);
        //获取I数据
        int nI = in.nextInt();
        int first = in.nextInt();
        String[] arrI = in.nextLine().split(" ");
        arrI[0] = String.valueOf(first);
       // System.out.println(Arrays.toString(arrI));

        //获取R数据
        int nR = in.nextInt();
        int[] arrR = new int[nR];
        int i = 0;
        while (in.hasNextInt()) {
            arrR[i] = in.nextInt();
            i++;
        }
        //排序
        Arrays.sort(arrR);
        //去重
        int slow = 0;
        for (int fast = 1; fast < nR; fast++) {
            while (fast < nR  && arrR[fast] == arrR[slow]) {
                fast++;
            }
            if (fast < nR) {
                slow++;
                arrR[slow] = arrR[fast];
            }
        }

        //去重后长度为slow + 1
        //设置二维数组，记录满足条件的i的index
        int[][] result = new int[slow + 1][nI + 1];
        for (int j = 0; j <= slow; j++) {
            int count = 0;
            for (int k = 0; k < nI; k++) {
                if (arrI[k].contains(String.valueOf(arrR[j]))) {
                    result[j][k] = 1;
                    count++;
                }
            }
            result[j][nI] = count;
        }
      
        //总共有多少个数
        int sum = 0;
        for (int j = 0; j <= slow; j++) {
            if (result[j][nI] > 0) {
                sum += result[j][nI] * 2 + 2;
            }
        }

        //输出结果
        System.out.print(sum + " ");
        for (int j = 0; j <= slow; j++) {
            if (result[j][nI] > 0) {
                System.out.print(arrR[j] + " ");
                System.out.print(result[j][nI] + " ");
                //循环输出index和对应值
                for (int k = 0; k < nI; k++) {
                    if (result[j][k] == 1) {
                        System.out.print(k + " " + arrI[k] + " ");
                    }
                }
            }
        }
    }
}