/*

    A simple implementation of a recursive method to list

    the moves to solve a Towers of Hanoi puzzle of size specified

    by the user. This version simply prints each move of a single disk

    to the console screen. It could easily be adapted to count moves.



    Record of revisions:

    Date                Programmer          Description of change

    ====                ==========          =====================

    March 2003          J. Rodger           Original coding from web examples

    May 2003            J. Rodger           I/O conversion to hsa classes

*/

import hsa.*;

public class SimpleHanoi

{

    // move a stack of height h from source to dest, using spare

    public static void moveDisks (int h, char source, char dest, char spare)

    {

	if (h > 0)      // a tower of height 0 is "already moved"

	{

	    // move top h-1 disks from source to spare peg

	    moveDisks (h - 1, source, spare, dest);



	    // move the bottom (biggest) disk to destination

	    Stdout.print ("move Disk " + h);

	    Stdout.println (" from " + source + " to " + dest);



	    // move top h-1 disks from spare peg to destination

	    moveDisks (h - 1, spare, dest, source);

	}

    } // moveDisks





    public static void main (String [] args)

    {

	// prompt user for number of disks in stack

	Stdout.println ("Demonstration of Moves to Solve Towers of Hanoi Puzzle");

	Stdout.print ("\tEnter number of disks (height of stack) to move:");

	int height = Stdin.readInt ();

	Stdout.println ("Tower of Hanoi of height " + height);

	moveDisks (height, 'A', 'C', 'B');

	Stdout.println ("Normal Program Termination");

    } // main

} // SimpleHanoi