Friends in unknown lands (chaos construction)
(Published on 11. June 2022, 13:10 by filuta)
I would like to dedicate it to two amazing people I met through this hobby of ours, Kafkapharnaum and Piatato, who are coincidentally also people who spent a lot of time with this puzzle helping me test it (until Piatato was finally able to crack it).
It was an amazing journey to set this one and I only hope it will be for you to solve it too. And as always, I will be happy to read your comments.
`
-Standard irregular sudoku rules apply, the regions, however, must be deduced by the solver. Some region borders are given and must be respected.
-All regions are orthogonally connected and are numbered by distinct numbers 1-9. The number of the region corresponds to the digit in its upper left corner (the leftmost cell in the highest row).
-A cell is called friendly, if its digit matches the number of its row, column or region (or more of them simultaneously).
-A border between two regions is friendly, if at least one of its adjacent cells is friendly.
-The number in the upper left corner of the cage shows the sum of the digits in the friendly cells within the cage. Digits may not repeat within a cage.
-The clues outside the grid show the number of the friendly borders in the corresponding row or column.
penpa+ link (answer check on digits and edges)
f-puzzles link
ctc app link
Solution code: row 4 and row 9 (without a comma or a space)
Comments
on 18. April 2024, 16:27 by Silverstep
Props to Niverio, KNT, kolot, polar, and anyone else who apparently solved this monster in less than 3 days; *that* must have been quite a feat. I'm going to find an easier puzzle to let my brain rest a bit, perhaps something by Agent.
Now that I have solved the original, should I check out the Redux version?
.............
congrat's on the solve! the newer one is about two thirds the same, but after that it develops very differently in more miraculous way one can say, rather than being a huge grind, which is something I nowadays prefer to ommit from my puzzles (except perhaps for the Noobahn - but in that case it's for a reason). The newer one is I think a better puzzle, but this one is a great challenge, which makes it appealing on its own (I think). I surely would like to hear your opinion/comparison.
on 15. November 2023, 21:52 by wullemuus
Wow!
After having solved the redux version (which saved a lot of time because of the same break-in) I haven't thought that the rest could take such a long time ... . To find the right borders esp. in the lower part was full of surprises. This time the friendly cells played an even more decisive role. Well, I'm so glad that I tried both versions- it was really worthwhile!
on 20. January 2023, 19:07 by Prutsbeest
This puzzle was brutal! It has cost me sweat and tears to solve this one! I am going to consider whether I should ever solve any more of your puzzles, Filuta, it's too time-consuming! ;-) thanks!
........
haha, thank you so much for your effort!
on 19. October 2022, 17:44 by hepcecob
This was absolutely insane. By far the hardest puzzle I've solved. Who ever said "go out to the park to solve", you'll need to bring a tent and a week's worth of food and water. Absolute insanity.
No biofication needed, everything is pure logic... but damn, you gotta fight for every single clue, all the way to the very end.
on 7. July 2022, 15:14 by Vebby
Brutal.
on 19. June 2022, 00:07 by PrimeWeasel
Almost the hardest puzzle I ever solved! I thought about giving up, but I just couldn't do it. What a ride, thanks filuta!
..................
Thanks, I'm happy to see you didn't find any alternative solution :)).
on 18. June 2022, 19:11 by Niverio
Do not try this at home. Go to a park or something, it will take a long time.
............
but jokes aside, it was impressive to see you and KNT solve it so (relatively) smoothly
on 18. June 2022, 19:11 by KNT
very easy puzzle
..........
haha, 3 mins 45 was still an impressive time :))
on 14. June 2022, 10:07 by kolot
Crazy puzzle. THE hardest puzzle I have ever solved. I am happy to see my name in the list of solvers of this puzzle.
................
I'm happy to see your name on it too, congrats for an amazing solve!
on 14. June 2022, 07:42 by henrypijames
By my own metric, this puzzle has to be rated 7/5 for difficulty - four times as hard as a typical 5/5 (and twice as hard as a 6/5).
The difficulty is not just off the charts, but utterly relentless, never letting up for a single step. Really felt like squeezing water out of rocks - which, theoretically, is possible (just like - but also as fantastical as - this puzzle):
https://www.nbcnews.com/science/environment/earths-rocks-contain-hidden-oceans-worth-water-n130961
Thanks to @filuta for chatting with me throughout my 16+ hour solve over three days. Never needed so much handholding on a puzzle.
..........
Thanks, it was actually quite something for me to see your progress almost in real time.
on 14. June 2022, 00:04 by JayForty
Extremely clever and tricky puzzle! Great fun exploring and trying to squeeze every tiny bit of logic out of the unusual ruleset. By each deduction it kept getting harder and harder, but still very satisfying. Thank you!
..........
Thank you!
on 13. June 2022, 16:53 by polar
Absolute madness of a puzzle! The break in really draws you in and each deduction afterwards feels like an achievement in itself. My favourite puzzles are always the marathon ones that are impossible to put down and this certainly met that criteria :) Thank you!
............
Thank you and congrats for a great solve!
on 13. June 2022, 13:38 by kolot
Finally I got the break-in. I have got two digits now. Very happy with that. :-)
on 12. June 2022, 17:07 by PrimeWeasel
I've got the break-in in half an hour, very cool I must say, and exciting, now I'm moving on to actually solving it :)
~Haha, I'm not getting anywhere yet.
on 12. June 2022, 13:21 by kolot
@Piatato: Why would I be scared? Only one day passed since the puzzle is published. I have 3 months and 29 days for figuring out the break-in. There is nothing to be scared of. :-)
on 11. June 2022, 23:40 by filuta
corrected rules in the online solving links
on 11. June 2022, 22:58 by filuta
corrected rules
on 11. June 2022, 22:32 by henrypijames
Digits may repeat in a cage?
.............
oh, thank you so much for noticing, completely missed that, just corrected the rules (they may not).
on 11. June 2022, 22:27 by Piatato
I really didn't mean to scare people off, btw, haha! I'll say that the break-in is unbelievably elegant! Please give this incredible puzzle a try, everyone!
on 11. June 2022, 17:25 by Kafkapharnaum
Piatato did it, the madlad! :D I still have the work I did on this one somehwere myself, so even though I'm not doing much puzzling these days, I'll certainly get back to it at some point -- I definitely did not forget about it; it's a lot of fun to work through, and as usual, mind-bendingly creative, or I should say even more than your usual unparalleled creativity in fact!
*Also I just saw you made it on CTC again, and a MARK movie-length no less, major congrats! :D
.............
oh, thank you!
on 11. June 2022, 14:28 by marcmees
Q: does the numbering of the regions happen in reading order L to R downwards ... whatever Left top cell comes first, second etc ... - it would give one easy digit to start with - or at random, to be found by the solver?
.........
No, there is not necessarily any relation between the position of a region and its number.
on 11. June 2022, 13:22 by Piatato
Thanks a lot for the dedication, and for such a fantastic puzzle! Although it took me more than four months to find the break-in, the break-in itself is not actually that hard. What followed was a wonderful way to spend 5+ hours. :-D Definitely one of the hardest puzzles that I have ever solved, but also very beautiful and rewarding throughout. Amazing construction!
...........
Thank you!
