C语言 阶乘数列

解题思路:

注意事项:

参考代码:

#include <stdio.h>

int main()

{

         double factorial( int n);

         double Sn = 0;

         for (int i = 1; i <= 30; i++)

         Sn = Sn + factorial(i);

         printf("%.2e\n", Sn);

         return 0;

}

double factorial( int n)

{

         double num = 1;

         while (n != 0)

         {

                 num = num * n;

                 n--;

         }

            return num;

}