public class Factorial
{
  public static void main(String[] args)
  {
    System.out.println( "Factorial of 18 is " + factorial(18) );
  }

  // Extensive use of variables
  public static long factorialOld( int x )
  {
    long f = 1;

    for ( int i = 1 ; i <= x ; i++ ) {
      f *= i;
    }

    return f;
  }
  
  // Reduction of variable use via recursion
  public static long factorial( int x )
  {
    System.out.println( "In factorial() method with x=" + x );

    if ( x == 1 ) {
      return 1;
    } else {
      return x * factorial( x - 1 );
    }
  }
}