题解 | #阶乘# 部分递归，部分使用vector

#include <iostream>
#include <vector>
using namespace std;
int jc(int a) //计算一个数的阶乘，采用递归
{
    if (a == 1) 
    {
      return a;
    }
     return (a * jc(a-1));
}
int main() {
    int a;
    while (cin >> a) 
    { // 注意 while 处理多个 case
         vector<int> ji; //存储奇数子项阶乘
         vector<int> ou; //存储偶数子项阶乘
         int temp = a;
         if(a % 2 == 0)
         {
            temp--;
          while (temp > 0) 
          {
            ji.push_back(jc(temp)); //存入奇数待求和序列
            temp -= 2;
          }
            temp = a;
            while (temp > 0) 
            {
            ou.push_back(jc(temp));//存入偶数待求和序列
            temp -= 2;
            }
         }else
         {
            while(temp > 0)
            {
                ji.push_back(jc(temp));
                temp -= 2;
            }
            temp = a;
            temp --;
            while (temp > 0) 
            {
                ou.push_back(jc(temp));
                temp -= 2;
            }
         }
         temp = 0;
         for (int i = 0; i < ji.size(); i++) 
         {
            temp += ji[i];   //求和并输出
         }
         cout << temp;
         cout << " ";
         temp = 0;
         for (int i = 0; i < ou.size(); i++) 
         {
            temp += ou[i];  //求和并输出
         }
         cout << temp;
         cout << endl;
    }
}
// 64 位输出请用 printf("%lld")