题解 | #神奇的口袋#

#include <iostream>
using namespace std;
int res = 0,n;
void func(int weight[],int nowIndex,int totalWeight){
    if(totalWeight<0)return;
    if(totalWeight==0)res++;
    else{
        for(int i=nowIndex;i<n;i++){
            func(weight,i+1,totalWeight-weight[i]);
        }
    }
}
int main() {
    cin>>n;
    int weight[n];
    for(int i =0;i<n;i++)
        cin>>weight[i];
    func(weight,0,40);
    cout<<res<<endl;
}
// 64 位输出请用 printf("%lld")

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