题解 | #称砝码#

import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt(); //砝码种数
        int[] m = new int[n]; //砝码重量
        int[] x = new int[n]; //砝码数量
        for (int i = 0; i < n; i++) {
            m[i] = in.nextInt();
        }
        for (int i = 0; i < n; i++) {
            x[i] = in.nextInt();
        }
        //set(dp[i]):加入砝码i后的重量数，dp[i] = dp[i-1]依次加上k个砝码i
        Set<Integer> set = new HashSet<Integer>();
        set.add(0);
        for (int i = 0; i < n; i++) {
            int weight = m[i];
            for (int j = 0; j < x[i]; j++) {
                Object[] setNums = set.toArray();
                for (int k = 0; k < setNums.length; k++) {
                    set.add((Integer)setNums[k] + weight);
                }
            }
        }
        System.out.print(set.size());
    }
}