题解 | 称砝码

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);
        int n = in.nextInt();
        int[] m = new int[n];
        int[] x = new int[n];
        for (int i = 0; i < n; i++) m[i] = in.nextInt();
        for (int i = 0; i < n; i++) x[i] = in.nextInt();
        ArrayList<Integer> list = new ArrayList<>(200000);
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < x[i]; j++) {
                list.add(m[i]);
            }
        }
        HashSet<Integer> res = new HashSet<>();
        HashSet<Integer> temp = new HashSet<>();
        res.add(0);
        for (int curM : list) {
            for (int r : res) {
                temp.add(r + curM);
            }
            res.addAll(temp);
        }
        System.out.println(res.size());
    }
}