1  import java.util.Arrays;

  2  

  3  /**

  4     A Towers of Hanoi puzzle with three towers.

  5  */

  6  public class TowersOfHanoi

  7  {

  8     private Tower[] towers;

  9  

 10     /**

 11        Constructs a puzzle in which the first tower has a given number of disks.

 12        @param ndisks the number of disks

 13     */

 14     public TowersOfHanoi(int ndisks)

 15     {

 16        towers = new Tower[3];

 17        towers[0] = new Tower(ndisks);

 18        towers[1] = new Tower(0);

 19        towers[2] = new Tower(0);

 20     }

 21  

 22     /**

 23        Moves a pile of disks from one peg to another and displays the movement.

 24        @param disks the number of disks to move

 25        @param from the peg from which to move the disks

 26        @param to the peg to which to move the disks

 27     */

 28     public void move(int disks, int from, int to)

 29     {

 30        if (disks > 0) 

 31        {

 32           int other = 3 - from - to;

 33           move(disks - 1, from, other);      

 34           towers[to].add(towers[from].remove());

 35           System.out.println(Arrays.toString(towers));

 36           move(disks - 1, other, to);

 37        }

 38     }

 39  }

 40