题解 | #称砝码#

// 值得mark一下

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);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextLine()) { // 注意 while 处理多个 case
            int n = Integer.valueOf(in.nextLine());
            String[] ws = in.nextLine().split(" ");
            String[] ns = in.nextLine().split(" ");
            int[] weight = new int[n];
            int[] num = new int[n];
            for (int i = 0; i < n; i++) {
                weight[i] = Integer.valueOf(ws[i]);
                num[i] = Integer.valueOf(ns[i]);
            }

            Set<Integer> ansSet = new HashSet<>();
            ansSet.add(0);
            for (int i = 0; i < n; i++) {
                List<Integer> oldAns = new ArrayList<>(ansSet);
                for (int j = 0; j <= num[i]; j++) {
                    for (int x : oldAns) {
                        ansSet.add(x + j * weight[i]);
                    }
                }
            }

            System.out.println(ansSet.size());
        }
    }
}