Obvious Killer II: everything looks wrogn
(Published on 8. April 2021, 14:10 by filuta)
A cage is an orthogonally connected region without repeats. A cage of size N is called obvious, if it sums to a number that can be expressed in only one way using N numbers 1-9 without repeats.
Rules of the puzzle: Standard sudoku rules apply. In addition, all possible 2,3 or 4-cell obvious cages that can be drawn in the finished solution are given as clues (i.e. there is a negative constraint on obvious cages) in the following sense:
every obvious cage of size 2, 3 or 4 that appears in the finished solution is either:
1) drawn in the grid (drawn clue), or
2) represented by its total written by a small number in the upper left corner of one of its cells (total clue).
The cages may intersect. Each total clue represents exactly one obvious cage. Each cage is represented by exactly one clue.
Have fun and thanks (in advance) for any feedback/comments!
f-puzzles link
Solution code: column 4 and row 5 (without a comma or a space)
Comments
on 2. March 2024, 04:43 by Sapio
This ruleset is now one of my favorites. This one is absolutely easier then the first puzzle, which required very precise logical deductions at every step, where this one falls apart easily after the inital break-in and early-to-middle section. That said, it's still fantastic and pleasure to solve. Thanks so much!!
on 26. November 2023, 09:05 by wullemuus
A wonderful amendment to your previous obvious killer puzzle. Super smooth solving path esp. in the first half (thanks to the tutorial ;D). In the second half I missed the CTC version (it's much easier to keep the trace there) but anyway- the deductions were strictly logic and easy to find. Great, great job as usual!!
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thanks a lot once again! and yeah, I should really take care of these old links, however, in case you need it you can use this link https://marktekfan.github.io/sudokupad-penpa-import/ to import directly from penpa/f-puzzles to the ctc app
on 24. May 2022, 18:46 by DiMono
This is definitely a difficult puzzle type. It might be that 2/5 difficulty on this type just happens to be 4/5 difficulty overall. I enjoyed the solve, especially the late cage deduction that unwinds the grid.
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haha, thank you, seems like a story of many of my puzzles
on 24. April 2022, 22:00 by PrimeWeasel
A very weird, but interesting puzzle. Understanding the rules took me a while, and the solve felt more like a 3 star to me. However, it was very cool to figure it out. I just think that the lay-out unnecessarily makes the understanding of the rules harder. 3s and 4s in cages of size 3 and 4 confused me at first.
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Oh, thanks for the comment. Yeah, looking at it in retrospect I'm more and more convinced that this was not the right choice for the tutorioal puzzle.
on 12. March 2022, 00:35 by Piatato
Great construction, and a fun puzzle! Looking forward to see if I can manage to crack its prequel! :)
on 2. September 2021, 13:43 by StefanSch
The difficulty of understanding the rules is more than 2 stars. But then it's a real fun with many nice logic steps.
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oh, thank you, yeah, I must say, I always thought of this ruleset as very intuitive, but really struggled to find any simple description of it.
on 18. August 2021, 17:26 by Prutsbeest
For some reason I find your puzzles to be extremely hard.. maybe it's because of the many different rules. In this case, I forgot about the negative constraint for a while which made things a lot harder :)
Anyway, very original set of rules, I enjoyed it!
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Thank you once more, yeah, thats the problem with this ruleset, I just hope, the puzzles make up for it. The real deal is the original Obvios Killer though (so I hope you will try that one too - no preassure ofc).
on 23. July 2021, 10:24 by cdwg2000
@filuta
I don't understand the rule set, if it is convenient, can you give a simple sample? Thanks!
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So for example three orthogonally connected cells containing 124 would make an obvious cage, since they sum up to 7 and 7 can be expressed in only one way using three digits (without repeats). On ths other hand, three orthogonally connected cells containing 135 would not make an obvious cage, since they add up to 8 and 8 can also be expressed as 125. Similarly, 9875 would again make up an obvious cage, whereas 9874 wouldn't.
There is a negative constraint on obvious cages of sizes 2,3 and 4. This means that if the finished solution contains orthogonally connected cells containing 124, then there must be either a dashed line around those cells, or there must be their total indicated by a small number written in one of the cells (can be any of them). The point is that every obvious cage must be indicated, so for the run of digits 124, the triple 124 is an obvious cage but also 12 is an obvious cage and must have its own clue. Moreover, no two cages may share a clue, even if two 12 cages intersect, they cannot be represented by only one clue.
Here are some clumps of digits:
https://f-puzzles.com/?id=yejwm7qa
and here are some possible ways in which they can be represented:
https://f-puzzles.com/?id=yzxcxafb
I hope it's more understandable now.
on 25. June 2021, 19:13 by Kafkapharnaum
Wow, I kept entering row 4, column 5 and I was losing my mind there, "WHERE did I mess up!?" lol
But hey, I got this one down of the two at least! It's certainly a lot more manageable to only have to deal with the lower end of the obvious totals, so again, you did an excellent job constructing it. Impressive work again, congrats!
filuta: yeah, I remember after solving your Gradius which was my by far hardest solved puzzle at that time I was so excited it took me like three or four tries to get the code right lol,
but seriously, thank you so much for continuing the tour through my puzzles and for the comment
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My pleasure! I really like how unique they all are, and I'm pleased to see that they seem to be getting more attention these days, including a solve and praise from the great zhergan I see! :D
on 12. April 2021, 17:41 by Gramor
I quite enjoy these obvious cages. Another really nice puzzle, thank you very much.
filuta: I'm glad you liked it. Thank you for your comment.
on 8. April 2021, 14:46 by filuta
fixed typo
