Java Illuminated, 5th Edition

13.6 Programming Activity 2: The Towers of Hanoi

A well-known problem that lends itself to an elegant recursive formulation is the Towers of Hanoi. Here it is:

• There are three towers, which we can represent as the source tower, the temporary tower, and the destination tower.

• We have a stack of n disks piled on the source tower; all the disks have a different diameter. The largest disk is at the bottom and the smallest disk is at the top.

• The goal is to transfer all the disks, one at a time, to the destination tower using all three towers for help. No larger disk can be placed on top of a smaller one.

The recursive solution to the problem for the general case (n >= 1) is as follows:

1. Transfer the top (n − 1) disks from the source tower to ...