From cube-lovers-errors@curry.epilogue.com Sun Jun 9 00:34:46 1996 Return-Path: cube-lovers-errors@curry.epilogue.com Received: from curry.epilogue.com (localhost [127.0.0.1]) by curry.epilogue.com (8.6.12/8.6.12) with SMTP id AAA17663 for ; Sun, 9 Jun 1996 00:34:45 -0400 Precedence: bulk Errors-To: cube-lovers-errors@curry.epilogue.com Date: Sat, 8 Jun 1996 20:48:40 -0400 From: der Mouse Message-Id: <199606090048.UAA04049@Collatz.McRCIM.McGill.EDU> To: CUBE-LOVERS@ai.mit.edu Subject: Re: verifying correctness of a cube > So, I was recently given a cube, which once again sparked my interest > in the whole thing, however it appears that the stickers have been > pulled off and re-arranged at some point. (The faces don't match any > I've seen mentioned in the archives or the various web pages.) Which doesn't necessarily mean it was attacked by a mad sticker-moving artist; it could just be an off brand. :-) > What would be the right way to put it back together to get a > "working" cube? Well, first I'd try solving it and see if I end up with something like two edge cubies colored the same, or a corner having colors that belong to opposite center cubies. If no such problem is found but a parity constraint is violated (eg, a single edge cubie flipped), it was just taken apart, so I'd take it apart and put it back together solved. If I _do_ find an "impossible" cubie, then I'd just take the stickers off and put them back on such that every face is a solid color. (I'd probably try to mostly-solve it first, so's to minimize the number of stickers that need moving, but that's a frill.) If you take all the stickers off, all states are the same; there is no mechanical state you have to match when putting the stickers back on. der Mouse mouse@collatz.mcrcim.mcgill.edu