From xirion!jandr@relay.nl.net Mon Jan 3 08:17:10 1994 Return-Path: Received: from sun4nl.NL.net by life.ai.mit.edu (4.1/AI-4.10) for /com/archive/cube-lovers id AA26254; Mon, 3 Jan 94 08:17:10 EST Received: from xirion by sun4nl.NL.net via EUnet id AA06106 (5.65b/CWI-3.3); Mon, 3 Jan 1994 14:17:08 +0100 Received: by xirion.xirion.nl id AA22788 (5.61/UK-2.1); Mon, 3 Jan 94 14:16:52 +0100 From: Jan de Ruiter Date: Mon, 3 Jan 94 14:16:52 +0100 Message-Id: <22788.9401031316@xirion.xirion.nl> X-Organization: Xirion Unix Software & Consultancy bv Burgemeester Verderlaan 15 X 3454 PE De Meern The Netherlands X-Phone: +31 3406 61990 X-Fax: +31 3406 61981 To: cube-lovers@ai.mit.edu To: Don.Woods@Eng.Sun.COM Subject: Re: 10x10 Tangle >Incidentally, I would be interested in seeing your program. (And am >willing to send you mine.) I'm always willing to learn something about >how to make combinatorial searches more efficient. Will be sent separately (and yes, I would like to see yours too!) >It's a shame, really. I'll bet that it would be possible to come up with >four Tangles that (a) really are different instead of being simple color >permutations of each other, (b) each have a unique solution (not counting >rotations) instead of two, and (c) can be combined to form a 10x10 that has >a unique solution. Well, strike the "unique" from (c) and I'd make the bet; >but with the "unique" I certainly wouldn't bet against it! When you limit yourself to 4 ropes with 4 colours, you always get 24 pieces, and when you want to build a puzzle of 25 pieces, you will have to duplicate one, which causes (a). Using 5 colours instead, creates a set of 120 pieces, from which you could probably pick 25 pieces (without duplication) which would satisfy both (a) and (b), and probably 4 such sets could be found to satisfy (c) as well, but such a puzzle would be less attractive, because the choice of 25 from 120 is somewhat arbitrary, and a puzzler would probably be more inclined to use all 120 pieces... Of course it is all a matter of taste. -- Jan