[7.8] Factorial

1. Implementation

Be aware that with factorials the calculated value grows large extremely quickly, which is why this

method returns a long. You could even make a case for returning a BigInteger instance here.

BigInteger objects have no upper bound; they allow for numerical integer values of any size.

// An iterative implementation of a factorial
public static long factorial (int n)
{
      if (n < 1)
         throw new IllegalArgumentExcpetion("n must be greater than zero");


      long res =1;
      for (int i =1; i < =n ; i++)
         res*=i;
    

      return res;




}