From cube-lovers-errors@mc.lcs.mit.edu Thu Nov 20 13:47:50 1997 Return-Path: Received: from sun30.aic.nrl.navy.mil by mc.lcs.mit.edu (8.8.1/mc) with SMTP id NAA19685; Thu, 20 Nov 1997 13:47:48 -0500 (EST) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Mail-from: From cube-lovers-request@life.ai.mit.edu Wed Nov 19 08:55:52 1997 Message-Id: In-Reply-To: <19971118.204255.7126.1.tenie1@juno.com> Date: Wed, 19 Nov 1997 08:56:30 -0500 To: Tenie Remmel , Cube-Lovers@ai.mit.edu From: Nichael Lynn Cramer Subject: Re: Rubiks Revenge moves Tenie Remmel wrote: >Is there an easy way to cycle three adjacent top edges on the >Rubiks Revenge? I can't find one shorter than 62 moves, but if >there was a short one I could simplify my solution greatly. > >. b c . . a b . >a . . . => c . . . >. . . . . . . . >. . . . . . . . > >Hopefully it won't mess up the corners, but it's ok if it does. The way I approach this is to begin with the following simple 3-cycle for edge cubies (note that this cycles only the cubies and leave the rest of the cube unaltered): 1] Imagine the involved cubies in the following configuration: Top face : . . c . Left face: . . . . . . . . a . . . . . . . . . . . . b . . . . . . 2] Perform the following sequence: - Rotate Front Face by 1/4 turn clockwise. - Rotate the slice just below the Top Layer by 180 dgs. - Rotate the Front Face by 1/4 turn counter-clockwise. - Rotate the Top Face by 180 dg. - Rotate Front Face by 1/4 turn clockwise. - Rotate the slice just below the Top Layer by 180 dgs. - Rotate the Front Face by 1/4 turn counter-clockwise. - Rotate the Top Face by 180 dg. This will result in: Top face : . . b . Left face: . . . . . . . . c . . . . . . . . . . . . a . . . . . . with all other cubies in their original locations. 3] Once this step is mastered, it is now only a question of moving the cubies that you want to swap into the approriate location for this operator to do its work. For example, in your example above this can be accomplished by (this assumes that the figure you have drawn above is your Top Face): - Rotating the Left-most two slices 1/4 turn clockwise (i.e. towards you) - Rotating the Top Face 1/4 turn counter-clockwise. If you now rotate the entire cube by 90dgs clockwise, you will see your three cubies are now in the proper location to use the above operator. (When you're done with the operator, repeat the steps just above in the reverse order to finish.) >I'd also like to see some short moves for the following 3-cycles: > >. * * . . . * . . . . . . . * . >. . . . * . . * * . . * . . . * >* . . . . . . . . . . * * . . . >. . . . . . . . . . . . . . . . These are just variations on the above. They will be left an exercise for the reader. ;-) Hope this helps. Nichael Nichael nichael@sover.net deep autumn my neighbor what does she do http://www.sover.net/~nichael/ --Basho