 |
|
|
|
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Take a standard Rubik's cube and rotate one face 90 degrees. Then rotate
an adjacent face 90 degrees in the same direction. How many times do you
have to repeat those two moves (repeatedly on the same two faces) before
the cube gets back to the same state it started in?
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Le 17/09/2015 11:08, scott a écrit :
> Take a standard Rubik's cube and rotate one face 90 degrees. Then rotate
> an adjacent face 90 degrees in the same direction. How many times do you
> have to repeat those two moves (repeatedly on the same two faces) before
> the cube gets back to the same state it started in?
>
There is a Rubik's cube in the IRTC (as source). It can be
programmed/shuffled with a string of text... so goes on topic and render
a few frames with the string generated according to the frame number.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
>> Take a standard Rubik's cube and rotate one face 90 degrees. Then rotate
>> an adjacent face 90 degrees in the same direction. How many times do you
>> have to repeat those two moves (repeatedly on the same two faces) before
>> the cube gets back to the same state it started in?
>>
> There is a Rubik's cube in the IRTC (as source). It can be
> programmed/shuffled with a string of text... so goes on topic and render
> a few frames with the string generated according to the frame number.
Interesting ... I needn't have written the SDL code to draw my own one
then :-) Still I'm interested in why the answer is so high for an
apparently simple system, but I'm having a hard time trying to visualise
in simpler terms what is going on.
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
Le 17/09/2015 17:53, scott a écrit :
>>> Take a standard Rubik's cube and rotate one face 90 degrees.
>>> Then rotate an adjacent face 90 degrees in the same direction.
>>> How many times do you have to repeat those two moves
>>> (repeatedly on the same two faces) before the cube gets back to
>>> the same state it started in?
>>>
>> There is a Rubik's cube in the IRTC (as source). It can be
>> programmed/shuffled with a string of text... so goes on topic and
>> render a few frames with the string generated according to the
>> frame number.
>
> Interesting ... I needn't have written the SDL code to draw my own
> one then :-) Still I'm interested in why the answer is so high for
> an apparently simple system, but I'm having a hard time trying to
> visualise in simpler terms what is going on.
>
It was only recently, IIRC, that it was proven that the deepest
distance from any 2 positions was at most 19 moves. (that includes the
hell-mixed position and the "all-faces-of-uniform-colour" position).
Then there is the problem: a path of 19 moves, but which ones, and in
which order.
A totally different issue.
I always solved my Rubik's with internet / programs.
The forest might only have a depth of 19, but you can circle around a
long time between the trees.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2
iJwEAQEIAAYFAlX69aAACgkQhKAm8mTpkW1D3QP+NwDROIrBFH5dDC92OTHVPhl+
oBlymtDULowvF4/7dMqii7YFf9MgJfTMC+h/QxwGAGd3pLdbJFRCEwC2nY/PdSAd
LThcEBXIRCTzK3wvD/XxxM+iLpfYOddDPAfMtToRs08ek+gbyNKBu9lSoQO9bywM
ooQyKYPL6NyoghQCylU=
=wmXH
-----END PGP SIGNATURE-----
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
| |
|
|
Am 17.09.2015 um 19:17 schrieb Le_Forgeron:
> Then there is the problem: a path of 19 moves, but which ones, and in
> which order.
> A totally different issue.
>
> I always solved my Rubik's with internet / programs.
My favorite algorithm was based on a brute force approach, which
actually turned out to be fairly efficient when implemented with some
reasonable assembler skills...
Post a reply to this message
|
|
| |
| |
|
|
|
|
| |
