Programming Faktorial in C++

#include
#include
void main()
{
int i,n;
long int p=1; // or long double p=1; for exponential result which I

cout<<"Enter No. ";
cin>>n;
if(n==0)
{
cout<<"1" ;
}
else
{
for(i=n;i>=1;i--)
{
p=p*i ;
}
}
cout<<"Factorial = "<
}