OJ Board

I have an idea. What if you try recursivity? Just like in math, when we use recurrent functions, we can apply the formulas also here:
We' ll use n!=(n-1)!*n, for any natural number n >=1.

#include <iostream.h>
int factorial(n)
{
if(n==1)
return 1;
else return factorial(n-1) * n;
}
main()
{
cout<<"n ...