题解 | #称砝码#

set：加入当前数量的砝码之前能产生的重量种类

import java.util.HashSet;
import java.util.Scanner;

// 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.hasNextInt()) { // 注意 while 处理多个 case
            int n = in.nextInt();
            int[] m = new int[n];
            for (int i = 0; i < n; i++) {
                m[i] = in.nextInt();
            }
            int[] x = new int[n];
            for (int i = 0; i < n; i++) {
                x[i] = in.nextInt();
            }
            HashSet<Integer> set = new HashSet<>();
            set.add(0);
            for (int i = 0; i < n; i++) {
                Integer[] array = set.toArray(new Integer[0]);
                for (int j = 0; j <= x[i]; j++) {
                    for (Integer integer : array) {
                        set.add(integer + m[i] * j);
                    }
                }
            }
            System.out.println(set.size());
        }
    }
}