# Looking for a Petrus or block solver



## Laura O (Sep 8, 2014)

Hi,

is there any Petrus or block solver (for 2x2x2 and 2x2x3 blocks)?

I sometimes used 'just another rubik's cube solver' to check FMC scrambles for blocks I had missed or alternative blocks, but it's down for some time now and it would be nice to have an offline tool.
It's obviously not possible to do this with ksolve since it allows a maximum of 8 pieces to be ignored ("Can't ignore permutation of more than 8 pieces in a big set.").

Any ideas?

Thanks
Laura


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## kinch2002 (Sep 8, 2014)

You could use Cube Explorer for this. You'd have to check one block at a time though

I could write a 2x2x2 solver in VBA/Excel though...sounds like a fun little project! I have an optimal cross solver, so it would work pretty similarly to that, probably with a lookup table of 4 move states, and then a brute force check of moves to try and reach those states.

Could even check for blocks with a premove by letting it loop it round with an extra move at the beginning of the scramble 

2x2x3 not so easy as the number of possible moves would probably become too large for it to run in any reasonable time. I would ask a real coder if you want that


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## Laura O (Sep 8, 2014)

kinch2002 said:


> You could use Cube Explorer for this. You'd have to check one block at a time though



Yes, I sometimes do that for interesting cases, but it's really annoying to do this manually for every case.
JARCS displayed the optimal solutions for all possible blocks so you could immediately see if there were any good (or better) solutions. It's actually a nice training tool when you know the optimal solution for a any specific block and then try to find it. At least I learned a lot from that.



> 2x2x3 not so easy as the number of possible moves would probably become too large for it to run in any reasonable time. I would ask a real coder if you want that



Well, a 2x2x2 solver would be great, a solver with premoves would be even better and a 2x2x3 solver would be amazing.


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## Johannes91 (Sep 8, 2014)

A fast 2x2x3 solver should not be too difficult to write these days, computers have more than enough resources. Premoves should be a fairly trivial addition. I wanted to write a FMC tool that would understand premoves and insertions etc. a long time ago but never got around to it.

JARCS is back up now for what it's worth. It's a real pity there is still nothing better and no offline tool.


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## slinky773 (Sep 8, 2014)

Johannes91 said:


> A fast 2x2x3 solver should not be too difficult to write these days, computers have more than enough resources. Premoves should be a fairly trivial addition. I wanted to write a FMC tool that would understand premoves and insertions etc. a long time ago but never got around to it.
> 
> JARCS is back up now for what it's worth. It's a real pity there is still nothing better and no offline tool.



OH YES THANK GOD IT'S BACK

FINALLY I CAN FIND XCROSSES XD


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## Lucas Garron (Sep 8, 2014)

Johannes91 said:


> A fast 2x2x3 solver should not be too difficult to write these days, computers have more than enough resources. Premoves should be a fairly trivial addition. I wanted to write a FMC tool that would understand premoves and insertions etc. a long time ago but never got around to it.
> 
> JARCS is back up now for what it's worth. It's a real pity there is still nothing better and no offline tool.



What's the backend setup? Could it be compiled to JS?


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## qqwref (Sep 9, 2014)

Would it be too crazy to make JARCS source available, or at least make an offline version in case it goes down? It looks like all the backend stuff (and the images) are done with CGI scripts.


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## Kirjava (Sep 9, 2014)

iirc the backend is haskell


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## Mike Hughey (Sep 9, 2014)

Johannes91 said:


> A fast 2x2x3 solver should not be too difficult to write these days, computers have more than enough resources. Premoves should be a fairly trivial addition. I wanted to write a FMC tool that would understand premoves and insertions etc. a long time ago but never got around to it.
> 
> JARCS is back up now for what it's worth. It's a real pity there is still nothing better and no offline tool.



Thank you, thank you, thank you - I've missed this so much!


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## Laura O (Sep 10, 2014)

Johannes91 said:


> JARCS is back up now for what it's worth. It's a real pity there is still nothing better and no offline tool.



Thanks a lot!
Time to practice blockbuilding again. 

So, is there a possibility you make the source code available?
Would be cool to have it run locally or even someone could make an offline version.


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