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From: edb@HQ.Ileaf.COM (Ed Blachman x4420)
Newsgroups: comp.text
Subject: Re: Wanted: Tower of Hanoi Solution
Message-ID: <1991Feb28.233931.2615@HQ.Ileaf.COM>
Date: 28 Feb 91 23:39:31 GMT
References: <8564@exodus.Eng.Sun.COM>
Reply-To: edb@HQ.Ileaf.COM (Ed Blachman)
Organization: Interleaf, Inc.
Lines: 42

In article <8564@exodus.Eng.Sun.COM> tut@cairo.Eng.Sun.COM (Bill "Bill" Tuthill) writes (tongue-in-cheek, I assume):
> We have converted most of our documents from troff to FrameMaker,
> but I am unable to convert this Tower of Hanoi program written
> in troff.  Could anyone supply the equivalent for FrameMaker or
> Interleaf?  Thanks in advance.
> 
> ================
> .de T
> .nr d \\$1-1
> .if \\nd .T \\nd \\$2 \\$4 \\$3
>  Transfer ring \\$1 from tower \\$2 to tower \\$3.
> .nr d \\$1-1
> .if \\nd .T \\nd \\$4 \\$3 \\$2
> ..
> Initial state:  \nR rings all on tower A; #1 on top.
> .T \nR A B C
>  Done!

Here is a way to do this with Interleaf 5:

(defun tower (depth a b c)
  (if (/= 0 (dec depth)) (tower depth a c b))
  (format t " Transfer ring ~D from tower ~C to tower ~C.~%" (1+ depth) a b)
  (if (/= 0 depth) (tower depth c b a)))

(defun do-tower (depth)
  (format t "~%Initial state: ~D rings all on tower A; #1 on top.~%" depth)
  (tower depth #\A #\B #\C)
  (format t " Done!"))
  
(do-tower 4)

The animated version, in which you see little rings lift themselves off of
 one pole and drop themselves onto another, is doable, if (we hope you'd
 agree) understandably not quite as terse.

We hope this was what you were looking for.... ;^)

-- ed

Ed Blachman	edb@ileaf.com
Paul English	pme@ileaf.com