题解 | #称砝码#

#include <iostream>
#include <unordered_set>
#include <vector>
using namespace std;

int main() {
    int n;
    while (cin >> n) { // 注意 while 处理多个 case
        vector<int> weight(n);
        vector<int> amount(n);
        for(int i=0;i<n;i++){
            cin>>weight[i];
        }
        for(int i=0;i<n;i++){
            cin>>amount[i];
        }
        vector<int> Weight;
        for(int i=0;i<n;i++){
            for(int j=0;j<amount[i];j++){
                Weight.push_back(weight[i]);
            }
        }
        int sum=0;
        for(auto & i:Weight){
            sum+=i;
        }
        int len=Weight.size();
        vector<vector<bool>> dp(len+1,vector<bool>(sum+1,false));
        for(int i=0;i<len+1;i++){
            dp[i][0]=true;
        }
        unordered_set<int> output;
        for(int i=1;i<len+1;i++){
            for(int j=1;j<sum+1;j++){
                if (j<Weight[i-1]) {
                    dp[i][j] = dp[i-1][j];
                }else {
                    dp[i][j] = dp[i-1][j] || dp[i-1][j-Weight[i-1]];
                }
                if(dp[i][j]){
                    output.insert(j);
                }
            }
        }
        cout<<output.size()+1<<endl;
    }
}
// 64 位输出请用 printf("%lld")