Message #4094

From: Andy F <legomany3448@gmail.com>
Subject: Re: [MC4D] 2x2x2x2: List of useful algorithms (please add yours)
Date: Wed, 01 Aug 2018 00:59:53 -0400

Hello!

Though I’ve just sent an email with my own solution
<https://docs.google.com/document/d/1vNc6bs3fl-XJ50Q96wOvy-grfpBVy_wmv9Ed_CLUqt0/edit#>,
but for the sake of completeness I’ll include my "double twist" algorithms
here. The rest are trivial or simply 4D use of 3D methods. These algorithms
preserve I/O orientation for the other seven pieces, but do not preserve
orientation on other axes or permutation at all.

Twist *OFRU* clockwise (relative to I/O): *[ R[ U’ R’ U2 ]: Iy Ix ]*
Twist *OBRU* counterclockwise (relative to I/O): *[ R[ U R U2 ]: Iy’ Ix’ ]*

The *Iy Ix* and *Iy’ Ix’* moves can be executed by moving the right and
left endcaps around the inner face, as can be seen in my solution video
<https://youtu.be/Fd9NUaO5AYo?t=5m58s>.

On Tue, Jul 31, 2018 at 3:28 PM, Jay Berkenbilt ejb@ql.org [4D_Cubing] <
4D_Cubing@yahoogroups.com> wrote:

>
>
> I’ll add my algorithms to this thread too.
>
> I don’t use very many algorithms per se: really only three (monoflip,
> gyro, and generalized isolate/manipulate/reverse). I do use an "algorithm"
> for corner orientation on the 2^3, but everyone has one of those.
> Otherwise, my approach is to solve in a certain sequence and use ad hoc
> moves. I’ll repeat the links to my main algorithms from my intro email. By
> the way, I don’t know where I came up with gyroscopic as an
> anti-abbreviation of gyro. Maybe I was trying to keep everyone on balance
> or something. Or maybe I hit M-/ and dynamically expanded it. (Sorry, emacs
> reference….parts of my brain are written in emacs lisp.)
>
> - 9:19 gyro <https://youtu.be/50Cjqwy2oj8>. My gyro rotation
> - 6:00 corner monoflip demo <https://youtu.be/eu14WmUzmnI>
> - 10: 2:30 pair swap demo <https://youtu.be/zscALET96LY> – this is
> just a special case of the isolate/manipulate/reverse pattern.. I use this
> pattern all over the place in different variants. Looking at the video,
> it’s possible that some intermediate states may be useful and may enable me
> to shorten this. I went for clarity over brevity.
>
> I haven’t translated these into any notation.
>
> For what it’s worth, I’ve avoided IY and OY moves (using Marc’s rotation)
> as well as the temptation to go with mod 2 = 0 instead of mod 4 = 0 (given
> that I can produce a fairly easy albeit lengthy series of moves to solve
> from a 180 twist on a half slice) and have taken a more purist position of
> adhering to canonical twists plus half twists with a cumulative mod 4 = 0.
>
>
> On Tue, Jul 31, 2018 at 3:19 PM Luna Harran scarecrowfish@gmail.com
> [4D_Cubing] <4D_Cubing@yahoogroups.com> wrote:
>
>>
>>
>> It really means Orient Last Cell, but that works too 😁😁
>>
>> And the algorithms solve that state, rather than generating it. The
>> reverse of the algorithm should generate it. Some of the algorithms might
>> be wrong though, I haven’t touched it in a while. Try inverting some of the
>> moves and see if that works.
>>
>> Macro files will have to wait a while, we’re about to go on holiday and I
>> won’t have access to MC4D, sorry. I think the notation is pretty standard
>> though.
>>
>> ~Luna
>>
>> On Tue, 31 Jul 2018, 18:32 Marc Ringuette ringuette@solarmirror.com
>> [4D_Cubing], <4D_Cubing@yahoogroups.com> wrote:
>>
>> Thanks, Luna! OLC seems to mean Orient Last Corners. That sounds
>>> useful. :)
>>>
>>> I need some help, though, I can’t make them work. Do you have a macro
>>> file you could attach?
>>>
>>> Trying to perform them on MC4D, I was able to make "One twist" do the
>>> right thing, but the 7 others I tried (Arm, Half Arm, Twist a, Twist b,
>>> Thumb a, Thumb b, Tick a) all did odd things that did not match the photos
>>> or the desired result. I wonder if our notations are subtly different?
>>> But that would make it unlikely that "One twist" would’ve worked for me, so
>>> probably not. Hmm.
>>>
>>> –Marc
>>>
>>> On 7/31/2018 9:03 AM, Luna Harran scarecrowfish@gmail.com [4D_Cubing]
>>> wrote:
>>>
>> Here’s my (still massively incomplete) set of algs for 2^4 OLC. They’re
>>> designed for the virtual puzzle, but some can be used easily on the
>>> physical puzzle.
>>>
>>> http://wiki.superliminal..com/wiki/2%5E4_algs
>>> <http://wiki..superliminal.com/wiki/2%5E4_algs>
>>>
>>>
>>> Feel free to add your own algs or cases, just try to keep to the system
>>> already there.
>>>
>>> ~Luna
>>>
>>>
>>> Or
>>>
>>>
>

–

"Engineers like to solve problems. If there are no problems handily
available, they will create their own problems." - Scott Adams