Just to confirm,
In Domino Castle we have to use all dominoes
i.e 1-1,1-2...1-7. ......7-7 so in all "49" dominoes right ?

or is it 1-1,1-2...1-7 then 2-2,2-3..2-7, 3-3.. so in that way 28 dominoes ??

Edited by swaroop2011 2013-04-11 3:06 PM

The standard set is made of 28 different dominoes; I am quite sure that's what we are supposed to use here (like in most domino-based logic puzzles).

ohk got it thank you :)

In domino Castle,
1) Is it possible to have a 2*2 domino (that is placing two dominoes adjacently) or 3*3 as there is no such restriction mentioned in rules ?
2) can castle walls touch each other at corners again nothing mentioned regarding this in rules ??

Edited by swaroop2011 2013-04-12 2:56 PM

You have 28 dominoes. Using all dominoes build a castle. Castle is connected freeform figure.

You can only place two dominoes adjacent (e.g. one above the other) if both left ends match, and both right ends match. You have a set of 28 different dominoes to use, once each...

You have to follow the given rules, but if the rules don't restrict something, then you can do it.

About Domino Castle : Please note that no domino can be used twice. (So each domino has to be used exactly once.)

We can see that in some submissions, a single domino (e.g. 3,4) is used twice. This is not allowed. Those submissions are invalid, and will not be considered.

Yet another note about Domino Castle : The task is to minimize the expresses (R-r)^2+(C-c)^2
Not to maximize it. We see a case, where the player has (probably) tried to maximize it.

I assume our optimised score gets adjusted if the solution is correct but our calculation of the score is wrong?

Yes. The entered values of expressions help us in sorting the submissions, thats it. But if it is wrong, it will be adjusted.

April Contest is now over. Submissions are not accepted any more.

Results will be out when Optimizers are checked manually.

Is it okay to post our optimiser results here before the checking?

Thanks Riad for a lovely set of puzzles.
Nearly all were "How can it be possible to logically solve THIS puzzle?" followed some time later by "AH! How clever..."
Very impressed.
Thank-you again.

Yes.

A total of 28 submitted Tetra Sudoku (+ 1 invalid). All submissions can be found in this pdf.
Riad has not double checked them yet, but if you notice any error or omissions, please bring it up.

Huh. Looking at the submissions, I now realize that I completely missed the "or some of them" part of the instructions. Oh well; doubt I could have done much better anyway. :)

Wow, I am wondering if a human should made up such a great sudoku with only 20 givens. Now I am ashamed of myself of being so naive.
Looking forward to rest of the results.
I must not forget to express my admiration to Riad and his great puzzles. Most of them were really hard and adroit. I should finnish all of them much faster, but forget to think about all the rules at all. I ignore number 0 in arrows and clouds and it costs me a lot of effort till I realized it.

Domino Castle Submissions pdf - Only the horizontal dominos marked, remaining are vertical.

Correctness of rules not checked (e.g. the one in page 11 is definitely invalid). If you notice any other grids missing rules, please post here.

22 submissions (out of which at least one is invalid)

I had the same problem.

One of the best contests ever. Congratulations for a fantastic set of puzzles. Spasiba Riad

Optimal Digital Ornament had most number of submissions.
The pdf is little tough to decrypt, but it is easy for those who have submitted the puzzle.
Riad probably has to spend lot of time checking this manually, so if you notice any errors / missing rules, please share.

My entry (110) has a typo. 2 cells transposed in the BL corner.

...If that cannot be allowed, could my previous 105 entry be considered?

I saw these two cells. It did not change your result (110).

Preliminary results have been published, I thank everyone for their participation and positive responses!

Congratulations to James (this is his second win in my contests), Tomoaki and Taro!

Once again thanks to Andrey Bogdanov, who tested all puzzles and translated them into English. And a special thanks to Deb Mohanty! He prepared pdfs with graphic solutions of optimization puzzles. It was a great pleasure holding contests with Deb .

Wow! I'm really pleased! I was hoping to do well, but was convinced I hadn't done _quite_ enough to win. Well done to Tomoaki and Taro also, Tomoaki in particular has beaten me in many optimising competitions over the years, and he wasn't far off again. :) (e.g. http://www.logic-masters.de/DOM/2009.php)
And this is the first time I've finished in the top 3 for any LMI test, so that's another personal milestone.

Big thanks to Riad, you are very clever at making new puzzle variations. Yes they are often hard, but we have a whole week to enjoy them and conquer their logic, which is a pleasant change from the other styles of 'speedy' competition. And the optimisers, well I struggled with those dominoes, it was early in the final morning when I finally found a solution that might be respectable...
And also thank you to Deb for the pdfs, it is great to see how others approached their solutions.