Swapping Two Edges and Two Corners on the 3^4

[Nicholas Frieler]

Does anybody know of an algorithm that is able to swap two edges and two corners on the 3^4? Preferably like a T-perm on the 3^3 so that all swapped pieces are on the top side of the 3^4, but any algorithm that swaps the pieces will do.

[Raymond Zhao]

Hi Nicholas,

You can always try doing the RKT version of the T-perm c:

I wrote an article on the general technique here

https://www.rayzz.me/articles/hypercubing/rkt.html

Raymond

Le mar. 16 févr. 2021 09 h 32, Nicholas Frieler <nmfr...@gmail.com> a écrit :

Does anybody know of an algorithm that is able to swap two edges and two corners on the 3^4? Preferably like a T-perm on the 3^3 so that all swapped pieces are on the top side of the 3^4, but any algorithm that swaps the pieces will do.

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[Nicholas Frieler]

Thanks! I had spent lots of time screwing around with the 3^4 and many of the 3^3 algs I know, but I never was able to figure how to undo the affected pieces not on the Top side.

[Nicholas Frieler]

So, I tried applying RKT to 2 different T perms, and neither of them worked, at least not completely. They both swapped the correct pieces but there was an extra rotation as you can see in the image. Have you run into this before, and, if so, do you know how to fix it?

On Tuesday, February 16, 2021 at 1:08:05 PM UTC-5 thermo...@gmail.com wrote:

[Alvin Yang]

Hey Nicholas, 

If you can somehow make sure you use the alg 2 or 4 times (or a multiple), then there would be a way out. 

If you just use it once, it would be 90 degrees misaligned. If you use it twice, it would be 180 degrees off, which there is a parity alg to fix. Check this page http://wiki.superliminal.com/wiki/3%5E4 for the alg. 

If you could use it 4 times, then it'll just align itself again.

Unfortunately, I'm not sure if it's possible to fix just a 90 degree alignment. 

Earlier on we had another guy who was doing a 4x4x4x4 and there was a similar issue. They had to use an alg that gave them a 90 degree misalignment on one of the inner layers. Unfortunately, if I remember correctly, they had to redo their solve and hopefully avoid the situation. 

Alvin 

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[Nicholas Frieler]

Unfortunately, what I want to use this for won't allow for the extra rotations.

[Raymond Zhao]

Oh wow

See I forgot the rotation at the end of the alg is a possibility. Like Alvin mentioned, the wiki lists the alg for the 180 degree "parity error" which is basically an RKT 180 degree supercube center rotation. However, just like how on a 3x3x3 supercube, one cannot rotate a single center by 90 degrees, I hypothesize it's a similar situation on the 3x3x3x3 with your attempt at finding a "pure" RKT T Perm. 

For the 4x4x4x4, I imagine that 90 degrees off case is caused by a parity error and that it cannot be replicated on a 3x3x3x3, though I've no proof. 

Raymond 

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[Nicholas Frieler]

Quite unfortunate. But now that I think about it, it might just be easier for me to stick with a 3 swap for each piece type. Doing setup moves with a pure RTK T Perm that doesn't mess up what I already have solved sounds like much more of a pain than I had originally thought.