comment {

    The Towers Of Hanoi
    Rebol
    Copyright (C) Amit Singh 2003. All Rights Reserved.
    http://hanoi.kernelthread.com

    Last tested under Rebol 042.
    http://www.rebol.com

    Usage: hanoi n
}

REBOL [
    Title:  "Hanoi"
    Date:   21-Mar-2003
    Author: "Amit Singh"
]

movedisk: func [f t] [
    prin f
    prin " --> "
    print t
]

H: func [n f u t] [
    either equal? n 1 [
        movedisk f t
    ][
        H do [n - 1] f t u
        movedisk f t
        H do [n - 1] u f t
    ]
]

hanoi: func [n] [
    either lesser? n 1 [
        print "usage: hanoi n, where n > 0"
    ][
        H n 1 2 3
    ]
]