题解 | #阶乘#

#include<iostream>
#include<vector>
using namespace std;
vector<long long>temp{0,1,2};
void sum_temp(int n){
    if(n<temp.size()){
        return;
    }
    for(int i=temp.size()-1;i<=n;i++){
        temp[i]=temp[i-1]*i;
    }
}
int main(){
    int n;
    while(cin>>n){
        sum_temp(n);
        long long sum1;
        long long sum2;
        for(int i=n;i>0;i--){
            if(i%2 == 0){
                sum2+=temp[i];
            }
            else{
                sum1+=temp[i];
            }
        }
        cout<<sum1<<" "<<sum2<<endl;
    }
    return 0;
}