题解 | #称砝码#C++

#include <iostream>
using namespace std;
#define WEIGHT 2000 * 10 * 15
int dp[WEIGHT];
int main() {
    int n;
    cin >> n;
    int w[n + 1];
    int nums[n + 1];
    for (int i = 1; i <= n; i++)
        cin >> w[i];
    int max_weight = 1;
    for (int i = 1; i <= n; i++) {
        cin >> nums[i];
        max_weight += nums[i] * w[i];
    }
    // cout << max_weight;
    int cur[11];
    dp[0] = 1;
    for (int i = 1; i <= n; i++) {
        for (int k = max_weight - 1; k >= 1; k--) {
            for (int j = nums[i]; j >= 1; j--) {
                cur[j] = w[i] * j;
                if(k >= cur[j])
                    dp[k] |= dp[k - cur[j]];
            }
        }
        // for(int i = 0; i < max_weight; i++)
        //     cout << dp[i] << " ";
        // cout << endl;
    }
    int res = 0;
    for(int i = 0; i < max_weight; i++)
        res += dp[i];
    cout << res << endl;
}
// 64 位输出请用 printf("%lld")

纯纯背包