Traversing Tree of Hanoi

[John Chong]

May I know how to write a java program to traverse a binary tree in preorder such that it implement the recursive tower of hanoi?

[Steve Fahlbusch]

John,
Usually the Towers of Hanoi problem is created in such a way as the recursive traversal of the data creates a "binary tree" in code. And usually it is considered in-order.
But given a general binary tree one traverses the orders by
recrusive moves, such as:
for in-order:

   Traverse( type root ) {
      if root == null quit
      Traverse ( root.left )
      Do-Something
      Traverse ( root.right )
   }

for pre-order:

   Traverse( type root ) {
      if root == null quit
      Do-Something
      Traverse ( root.left )
      Traverse ( root.right )
   }

for post-order:

   Traverse( type root ) {
      if root == null quit
      Traverse ( root.left )
      Traverse ( root.right )
      Do-Something
   }

for towers of hanoi, you can create by

   TOH( level, source_post, target_post, spare_post )
      if level < lowestLevel quit
      TOH ( level-1, source_post, spare_post, target_post )
      MoveDisc ( level, source_post, target_post)
      TOH ( level-1, spare_post, target_post, spare_post )
   }

[This message has been edited by Steve Fahlbusch (edited February 14, 2001).]