计算1！+2！+......+n!

#include<stdlib.h>
int main()
{
 int i = 0;
 int sum = 0;
 int n = 0;
 int p = 0;
 int j = 0;
 scanf("%d", &n);
 for ( j= 1;  j<=n ; j++)
 {
  p = 1;
  for ( i= 1;  i<=j ; i++)
  {
   p = p*i;
  }
  sum = sum + p;
 }
 printf("sum = %d\n", sum);
 system("pause");
 return 0;
}