题解 | #称砝码#

import java.util.HashSet;
import java.util.List;
import java.util.Scanner;
import java.util.Set;
import java.util.stream.Collectors;


public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        // 有多少种砝码
        int n = sc.nextInt();
        sc.nextLine();
        // 每种砝码的重量
        String line2 = sc.nextLine();
        List<Integer> mList = Arrays.asList(line2.split(" ")).stream().map(Integer::valueOf).collect(Collectors.toList());
        // 每种砝码的数量
        String line3 = sc.nextLine();
        List<Integer> xList = Arrays.asList(line3.split(" ")).stream().map(Integer::valueOf).collect(Collectors.toList());

        System.out.println(chengfama(n, mList, xList));
    }

    private static int chengfama(int n, List<Integer> mList, List<Integer> xList) {
        Set<Integer> rSet = new HashSet<Integer>();
        rSet.add(0);
        for (int i = 0; i < n; i++) {
            int m = mList.get(i);
            int x = xList.get(i);
            for (int j = 0; j < x; j++) {
                Set<Integer> tempSet = new HashSet<>(rSet);
                for (Integer w : tempSet) {
                    rSet.add(w + m);
                }
            }
        }
        return rSet.size();
    }
}