/**
 * This class contains a number of examples of recursive methods.
 *
 * @author Franck van Breugel
 */
public class Print
{
    /**
     * Prints the given number of *'s.
     *
     *  @param n an integer.
     *  @pre. n >= 0.
     */
    public static void stars(int n)
    {
	if (n == 0)
	{
	    // do nothing
	}
	else
	{
	    System.out.print('*');
	    Print.stars(n - 1);
	}
    }

    /**
     * Prints the given number of *'s followed by the given number
     * of +'s.
     * 
     * @param n an integer.
     * @pre. n >= 0.
     */
    public static void starsAndPlusses(int n)
    {
	if (n == 0)
	{
	    // do nothing
	}
	else
	{
	    System.out.print('*');
	    Print.starsAndPlusses(n - 1);
	    System.out.print('+');
	}
    }

    /**
     * Prints done.
     *
     * @param n an integer.
     *  @pre. n >= 1.
     */
    public static void done(int n)
    {
	if (n == 1)
	{
	    System.out.println("done");
	}
	else
	{
	    if (n % 2 == 0)
	    {
		Print.done(n / 2);
	    }
	    else
	    {
		Print.done(3 * n + 1);
	    }
	}
    }
}