Stostone Cold (Chaos Construction)
(Published on 10. April 2024, 20:09 by Phistomefel)
I would like to thank bolgat whose cool puzzle Stostone Fillomino drew my attention to this puzzle type in the first place.
Here are the rules for this puzzle:
- Fill the cells with the digits 1 to 8 such that each digit appears exactly once in every row, column and region.
- A region is a collection of eight orthogonally connected cells. Determining the shape of the regions is part of the puzzle.
- Each region has exactly one clue which is a small number in the upper left corner of some cell in that region (not necessarily the top left cell).
- Shade some cells such that
- no orthogonally neighboring shaded cells are separated by a region boundary,
- all shaded cells within a region are orthogonally connected and
- the digits in all shaded cells within a region sum to the region's clue.
- If all of the shaded groups were to fall straight down without changing shape (like in Tetris), they must fill the bottom half of the grid without leaving any gaps and without any of the shapes sticking out into the top half.
If you want to try the example, you find the link here.
The actual puzzle is also available online in Penpa Plus and in the CTC-App (Many thanks to firespire!). Have fun solving!
A small hint on this puzzle in Penpa: Since some cells have to be shaded and meanwhile the grid has to be decomposed into regions, I can recommend the tool Composite->"Area/Field"->"Edge/Aux-Line" to keep track of cells belonging to the same region with the help of the Aux-Lines.
Solution code: The first two rows
Comments
on 31. May 2024, 21:29 by PlumpestPlumber
I enjoyed this very much. Thank you for this wonderful puzzle.
on 4. May 2024, 09:24 by Styku
First time I did your puzzle before Simon did :) I am very proud of myself. It was very hard for me because I did not understand the tertis rule. You are my favourite constructor. Thank you for your effort in creating these masterpieces!
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Thanks a lot for the solve and your very nice comment, Styku! Also, well down solving this puzzle despite the unfamiliar ruleset! (:
on 18. April 2024, 23:22 by KNT
cool
on 16. April 2024, 19:20 by Prutsbeest
Wow, this took me a long, long time to figure out the logic! Very nice indeed!
on 16. April 2024, 17:23 by henrypijames
Then you should set a 9×9 with the fallen shapes filling the "lower two-third".
on 16. April 2024, 12:35 by sunnyjum
Fantastic puzzle, I loved how well the "tetris" aspect played into it
on 14. April 2024, 21:27 by Christounet
Great puzzle ! Super interesting region logic here. There is one question I kept asking myself while solving : why did you set this on an 8x8 grid rather than a 9x9 ? Was there something that did not work on a larger grid ? Or did you find the logic was tighter with a smaller one ? Or was it just random ?
Anyway, thanks for setting and sharing :)
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Thanks for the nice feedback! The reason it is on 8x8 is merely because the original Stostone rules say that the lower half should be entirely filled with the shaded shapes and saying "lower half" feels nicer than "the bottom five rows". :)
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Haaa, I had not thought about that ! Makes sense. Thanks.
on 14. April 2024, 21:25 by mihel111
Wonderful puzzle. One of the greatest in chaos construction.
on 14. April 2024, 19:31 by MaizeGator
Awesome puzzle and execution of the ruleset.
For anyone struggling, I highly recommend solving the bolgat Stostone Fillomino first. There is a comment on that puzzle which seems to be the inspiration behind this puzzle...
on 14. April 2024, 16:12 by wand
loved the region-building in this one - makes me want to do more stostone hybrids
on 14. April 2024, 15:32 by MaizeGator
Awesome puzzle and execution of the ruleset.
For anyone struggling, I highly recommend solving the bolgat Stostone Fillomino first. There is a comment on that puzzle which seems to be the inspiration behind this puzzle...
on 14. April 2024, 03:57 by ONeill
Awesome! Hope we are lucky enough to see Simon tackle this one :)
on 13. April 2024, 22:46 by Shape
And once again, such a distinctive Phistomefel puzzle - thank you, that was a joy to solve
on 13. April 2024, 12:07 by cmb
fantastic puzzle!
smooth logical path.
irregular suduku not too hard.
a real joy!
on 13. April 2024, 02:12 by Arashdeep Singh
Fantastic puzzle, really enjoyed solving it, thanks!
on 12. April 2024, 21:54 by Phistomefel
Thanks a lot for the kind words, everyone! (:
on 12. April 2024, 17:35 by Jesper
A lovely puzzle, really enjoyed it, thanks!
on 12. April 2024, 15:23 by Phistomefel
Added CTC link. Thank you, firespire!
on 12. April 2024, 15:18 by Phistomefel
Rule clarification. Thanks, henrypijames!
on 12. April 2024, 14:30 by firespire
https://sudokupad.app/a21fmb469t
(Thanks to MarkTekfan SudokuPad Penpa+ Importer website.)
I’m a very poor error-prone solver so I appreciate this is a very binary puzzle, you are either right or wrong. It’s the fact you can quickly see if you have got onto a wrong path plus you are gracious to input the solution which Sven’s Sudokupad then allows me to constantly check any number I enter against.
I felt as if you were already anticipating my mistakes and were ready to stop me in my tracks, I’m amazed how clever you are to create such a puzzle. I also appreciate how the region size is a given and there are no question-mark clues. I could see you attempted to made the irregular Sudoku at the end very approachable even though I missed one easy deduction. I’m so happy I was able to work my way through your puzzle and experience your genius.
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Thank you very much for this wonderful feedback! I indeed tried to make the irregular Sudoku part at the end easier this time, since it can be very frustrating to be almost finished, but fail to spot some devious steps like I did in previous puzzles of mine. Also, many thanks for the CTC link and the tip with MarkTekfan SudokuPad Penpa+ Importer website!
on 12. April 2024, 14:09 by MagnusJosefsson
Fantastic puzzle, really new twist to chaos construction and it works really well! Thank you Phistomefel!
Thank you also henry for the shoutout.
on 12. April 2024, 07:18 by henrypijames
I don't understand what rule 5 means - the terms "group", "fall", "straight", "change", "half", "gap" are all undefined. Neither the example nor the linked fillomino puzzle brings any clarity either.
Edit: Oh, wait! Is this a Tetris reference? If so, it would be super helpful to mention that. Because sudoku grids are usually static (and flat, unless aquarium rule is invoked) - nothing falls or changes.
But speaking of which, one recent sudoku that does feature a standard grid with a non-static, multi-dimensional ruleset is Sea Level Rise (#HEV) by Magnus - an ingenious puzzle that deserves much more attention than it's gotten so far.
Another question remains: Do the shaded cells have to cover exactly the bottom half and no more after falling down, or can they also stick out into the top half in addition?
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Thanks for the questions and remarks, Henry! The Tetris analogy is very good - the shaded shapes fall to the bottom of the grid like Tetris shapes.
And the shapes are not allowed to stick out into the top half after falling down. I will add that to the rules. Thank you! :)
on 11. April 2024, 20:59 by yttrio
Awesome hybrid! I had to be very careful when making deductions, as it was really easy to make a false assumption, but it was still really fun to solve!
on 11. April 2024, 00:49 by RJBlarmo
Nice puzzle, I always enjoy these hybrids!
on 11. April 2024, 00:21 by josebastian8
Half an hour wasted because I was thinking about 9-cells regions xD. Finally done after some trial and error (and 2 hours), very nice logic!
