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Best Answer superprismatic, 03 May 2013 - 09:22 PM

Spoiler for My best solution so far

Go to the full post


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#1 bonanova

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Posted 22 April 2013 - 09:19 PM

Eight cubes are placed on a 3x3 grid with the center location vacant.

The top of each cube is distinguished by a certain color, say, as is the bottom, but by a different color.

The side faces do not matter.

 

sp304blocks.gif

 

Any adjacent cube may be "rolled" into the vacant location by giving it a 1/4 turn about a bottom edge.

By a series of such rotations, a configuration may be reached where the eight cubes are inverted,

and the center location is again vacant.

What is the minimum number of moves that accomplishes this?

 

All moves are by rotation.

A cube may not be slid into the vacant spot.

The cubes do not have to return to their original location.

 

You can simulate this puzzle using eight dice.

Initially a "1" shows on the top faces; finally a "6" shows on the top faces.

 

To record a solution, U, D, L and R can be used for up, down, left and right.

The first three moves will alternate vertically and horizontally.

Therefore, you may begin your solution with URD.


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#2 TimeSpaceLightForce

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Posted 23 April 2013 - 04:10 AM

I've seen one in a Escape the Room Game. Since we are just playing for the least rolls it might be helpful if we use the mini program

http://www.jaapsch.n...t/eightcubj.htm .Enjoy ..Don't press SOLVE.


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#3 bonanova

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Posted 23 April 2013 - 08:50 AM

I've seen one in a Escape the Room Game. Since we are just playing for the least rolls it might be helpful if we use the mini program
http://www.jaapsch.n...t/eightcubj.htm .Enjoy ..Don't press SOLVE.


Great.
Start out all white, end up all yellow. Fewest moves.
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#4 superprismatic

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Posted 03 May 2013 - 09:22 PM   Best Answer

Spoiler for My best solution so far


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#5 bonanova

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Posted 05 May 2013 - 10:56 PM

Spoiler for My best solution so far


Good solve.
As far as I know this is the minimum number of moves (proven by simulation.)
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#6 superprismatic

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Posted 05 May 2013 - 11:40 PM

I solved it with by exhaustion over all possible paths of moves less than 38.

I saw that Martin Gardner's column of 1975 had a 38-move solution, so I started there.


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