题解 | #阶乘#

#include <iostream>
using namespace std;


int main() {
    int a;
    while (cin >> a) { // 注意 while 处理多个 case
        long long int y1=0,y2=0,y=1;
        bool flag=1;
        for(int i=1;i<=a;++i){
            if(flag){
                y *=i;
                y1+=y;
                flag = 0;
            }
            else{
                y *=i;
                y2+=y;
                flag = 1;
            }
        }
        cout<<y1<<' '<<y2<<endl;
    }
}