#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
//计算n的阶乘for循环实现
int Sub(int n)
{
  int sum = 1;
  for (int i = n; i >= 1; i--)
  {
    sum = sum*i;
  }
  return sum;
}
int main(){
  int b = 0;
  printf("请输入一个数，并计算它的阶乘\n");
  scanf("%d", &b);
  int a = Sub(b);
  printf("阶乘为%d\n",a);
  return 0;
}

#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
//n的阶乘累加的实现
int Sub1(int n)
{
  int sum = 1;
  for (int i = n; i >= 1; i--)
  {
    sum = sum*i;
  }
  return sum;
}
int LeiJia(int n)
{
  int ret = 0;
  for (int i = n; i >= 1; i--)
  {
    ret = ret + Sub1(i);
    continue;
  }
  return ret;
}
int main(){
  int a = 0;
  scanf("%d",&a);
  int b = LeiJia(a);
  printf("阶乘的累加为%d", b);
  return 0;
}