Chaos Construction: Lighthouse
(Published on 15. November 2021, 22:52 by Phistomefel)
A word of caution: This puzzle is difficult and requires a certain amount of visualization. The logic behind the puzzle still feels a bit alien to me. My recommendation is therefore to get acquainted with the logic by first solving the given example.
Here are the rules:
- Every digit from 1 to 9 has to appear once in every row, column and region.
- The regions first need to be determined. Every region is a set of nine orthogonally connected cells.
- A digit in a circle indicates the number of borders between regions it sees in its row and column. Note that the edge of the grid does not count toward this total.
For illustration, here is an example on a 6x6 grid:
Here you find a link to the example.
The puzzle is available online via Penpa Plus, as well. The additional space outisde of the grid is for notes. Have fun solving!
The links to the example and the puzzle each come with a solution check. For it to work, please use green, red or blue numbers and green edges. Additionally, please remove potential notes outside of the grid when you have finished the puzzle.
Unfortunately, it already occured that the solution check didn't work. If Penpa doesn't verify your solution, please just enter the solution code here.
Solution code: Columns 5 and 8
Comments
on 24. November 2021, 10:55 by Phistomefel
@henrypijames: Es ist wirklich erstaunlich, wie schnell einige das Rätsel gelöst haben. Falls es dich irgendwie tröstet - ich bin mir sehr sicher, dass ich das Rätsel niemals in der Zeit bis zum Livestream gelöst hätte, wenn jemand anderes das Rätsel gebastelt hätte.
Davon abgesehen wird es bestimmt noch ein paar Chaos Constructions von mir geben, nur wird's ein wenig dauern. :)
@AppleSaws: I think 8 hours is a very respectable time. Thanks for solving it!
on 24. November 2021, 02:21 by AppleSaws
Took me 8 hours across two days, though I probably could have saved an hour or two if I didn't stay up as late as I did working on it. Incredible puzzle.
on 23. November 2021, 05:23 by henrypijames
Dieses Rätsel ist wahrlich eins, das die Spreu vom Weizen trennt - und ich bin offenbar Spreu. :(
Es war von Anfang an klar, dass Simon das Rätsel zeitnah anpacken würde - und dass ich mich nicht verwehren kann, sein Video zu schauen. Die Frage war also, ob ich schaffen würde, vorher das Rätsel zu lösen. Das Ziel verfehlte ich ganz klar, fand nicht einmal den vollständigen Eingang - ob Simon sein Video länger aufgeschoben hatte als von mir erwartet.
Ich hoffe, dass es noch viele weitere Chaos-Construction-Rätsel von Phistomefel gibt, und werde mich das nächste Mal noch stärker anstrengen. :)
on 22. November 2021, 08:45 by Phistomefel
@SenatorGronk: Wow, I am blown away that I have contributed to such a moment. Thank you!
@DiMono: Thank you so much for the kind words! The idea for this ruleset came from me wanting to do something with region borders and a puzzle type called "Leuchttürme" or in English "Lighthouses". There the number in a lighthouse indicates the number of ships it sees in the row and column.
@Gnosis66: Many thanks for the nice comment! I am glad that enjoyed how the logic unfolded.
on 22. November 2021, 03:24 by Gnosis66
This was an exquisite puzzle. Like @PixelPlucker, it took me a long time at the beginning to fully grasp the nuances of the rules. It was marvelous to see the logic unfold after that.
By the way, the Penpa solution check worked for me.
on 21. November 2021, 21:35 by DiMono
What a wonderful puzzle! Very different types of logic to work through in this one. I don't know how you come up with some of these constraints, but I'm glad that you do.
on 21. November 2021, 21:17 by SenatorGronk
Whew! I think when I finally figured out the shape of all the regions, it was the greatest moment in my nearly 5 decades of puzzle solving.
Simon's livestream is a couple of hours away. Can't wait to watch him tackle this.
on 21. November 2021, 13:32 by Phistomefel
@JayForty: Many thanks for your warm and wonderful feedback! I am very pleased to see that you enjoyed discovering the logic in the puzzle. :)
on 20. November 2021, 22:11 by JayForty
An incredible puzzle! Extremely rewarding considering that at first glance it just looks impossible. Then you start chipping away, revealing more and more wonderful logic, some of which were completely new and original, at least to me.
Even the irregular sudoku had some really nice deductions and posed more of a challenge than I expected. Thank you!
on 20. November 2021, 17:30 by Phistomefel
@Knitabit: Really well done solving this beast! :)
And thank you for your kind words!
on 20. November 2021, 16:09 by Knitabit
I can't believe I solved this puzzle! From the moment I found CTC on youtube I always tried your puzzles and somehow always succeededin solving them, altough it often took many hours. I almost accepted that it wouldn't happen this time. It was beautiful as always, thank you!
on 20. November 2021, 09:52 by Phistomefel
@FryTheGuy: Congratulations on solving the puzzle and many thanks for the nice comment!
on 20. November 2021, 08:35 by FryTheGuy
Wonderful puzzle!
I ended up working on this puzzle for 30 minutes at a time over the last few days to let my brain cool off between deductions.
The solve felt somewhat non-linear in that I ended up proving a lot of things that were not very useful individually but came together to finally unlock the puzzle.
on 17. November 2021, 18:59 by Phistomefel
@Vebby: Thank you very much for your kind words! :)
@kolot: Thank you so much for your perseverance and for the nice comment!
on 17. November 2021, 07:14 by kolot
Very nice logic! I don't know how much time I spent on this puzzle, probably more than 5 hours. It took me time to understand how I am supposed to approach the puzzle but I finally asked the correct questions and got the break-in. Then I broke the puzzle twice but found my mistakes and got the solution. I think each deduction must be made carefully because it is easy to make logical mistakes in this puzzle. It was a very fun journey after all.
I think Simon will try this puzzle on a live video, and this puzzle is a good candidate for being his longest video.
on 16. November 2021, 23:52 by Vebby
Brilliant puzzle! The beginning lighthouse logic was so interesting. Thanks for another gem, Phistomefel! :)
on 16. November 2021, 19:23 by Phistomefel
@Polar & MagnusJosefsson: Thank you very much for lovely comments. It is a joy for me to read that you've enjoyed the puzzle.
on 16. November 2021, 19:18 by Phistomefel
Platz für Notizen und besserer Solution Check - vielen Dank an Dandelo für die Hinweise!
on 16. November 2021, 17:33 by MagnusJosefsson
Great puzzle, very demanding but also extremely satisfying! I loved it!
on 16. November 2021, 13:50 by Dandelo
@phistomefel: Ja, das mache ich auch manchmal. Aber wenn ich da mehrere Möglichkeiten notieren will, ist das zu eng. Und mit dem Smartphone erst recht.
@polar: Clone the tab before resize.
on 16. November 2021, 13:42 by polar
Oh my goodness. Words are failing me on how to describe this puzzle - fiendishly magical! Even when I knew where to look, it still took me a good amount of time to visualise it properly and unpick the puzzle.
The example puzzle is an absolute must in my opinion. I was a little familiar with the idea of counting borders from cdwg2000's series that used a similiar idea, but the example puzzle here was totally necessary for me to grasp the right questions to ask in the main puzzle.
I felt such a sense of achievement when I finally got the 9 regions that my brain melted for the 2nd portion and scanning properly suddenly became very taxing indeed haha.
Thank you for constructing this! It is surely a strong contender for setting a new solve time record for Simon :)
Edit: I always add some space for notes at the beginning of a solve, as Dandelo suggested although I didn't need it for this one in the end. I didn't realise removing those extra rows / columns would allow the answer check to work, but I can confirm it certainly does! I also recommend to add extra space at the beginning of a solve since it can wreck havoc on the 'undo' function if it's used during the solve.
on 16. November 2021, 12:03 by Phistomefel
@Jesper: Thank you for nice comment and the hint about the tag, Jesper! :)
@Dandelo: Das freut mich, wenn das Beispiel schon einmal gefällt. Der Tipp zum Solution Check ist super - das schaue ich mir heute Abend einmal an.
Zum Thema "Platz für Notizen": Beim Erstellen hatte ich eigentlich immer unter Numbers die 7. Option gewählt, die es erlaubt an den Seiten eines Felds kleine Zahlen einzutragen. Das geht auch super außerhalb des Gitters.
on 16. November 2021, 12:03 by Phistomefel
Tag ergänzt
on 16. November 2021, 11:13 by Jesper
A wonderful puzzle based on some quite unusual and exciting deductions. Thanks, Phistomefel!
By the way, you might want to add the "Chaos Construction (Variant)" tag, as some solvers that are generally not too keen on Sudoku still like these types and may look for them using the tag.
on 16. November 2021, 09:13 by Dandelo
Das Beispiel ist schon mal klasse.
Du solltest "Edge - Ignore Edges on Grid Borders / Givens" einschalten, das ist eine typische Fehlerquelle bei der Lösungsüberprüfung. Leider nicht die einzige, aber Swaroop ist dankbar für jede (Fehler-)Rückmeldung und reagiert sofort, wenn es kein größeres Problem ist.
Und es wäre hier hilfreich, am Rand jeweils eine Extrazeile bzw. -spalte für Notizen zu haben. Man kann sie als Löser selbst einfügen (Resize), aber dann funktioniert der Lösungscheck nur, wenn man sie wieder entfernt.
on 16. November 2021, 07:56 by Phistomefel
@Piatato: Thank you so much for the wonderful comment! I am just glad you enjoyed the puzzle. :)
on 16. November 2021, 05:34 by Piatato
A fantastic puzzle! It took me the whole night, but that was definitely worth it! One of my all time favorites! :-D
on 15. November 2021, 23:15 by Phistomefel
Solution check problem
on 15. November 2021, 22:54 by Phistomefel
Please don't hesitate to write a hidden comment if you feel stuck. I will try to help you with a small hint.
