Factor

#include <iostream>

using namespace std;

int main()
{
setlocale(LC_ALL, "rus");

unsigned long n, i = 2, j = 1;
cout<<"Введите N!(0<N<34) -> ";
cin>>n;
for (; i <= n; i++)
j *= i;
cout<<n<<"! = "<<j<<'\n';
system("pause");
return 0;
}