Reversing Valve
(Published on 1. April 2023, 11:00 by ViKingPrime)
PUZZLE:
RULES:
Normal Sudoku rules apply.
• Killer: The value of digits within a cage must sum to the number given in the top-left corner.
• Thermometer: The value of digits along a thermometer must increase from the bulb to the tip.
MODIFIER:
• Hot/Cold: There are 9 Hot cells contained within the grid comprising a set of the digits from 1-to-9. Each row, column and box contains exactly one Hot cell. There are nine 9 Cold cells contained within the grid following the same rules as the Hot cells. A cell may have only one of these roles.
for Killer/Thermo value(s)
Hot cells increase the value of the contained digit by 1.
Cold cells decrease the value of the contained digit by 1.
INTRODUCTION:
I've noticed something lately, which is that I quite enjoy puzzles that change the normal rules of sudoku. I seem to specifically gravitate to puzzles that adjust the expected values of cells (for some odd reason) but I've also noticed that this isn't generally the norm. I would love to see them become more popular.
This puzzle is based on the work of brennan77, who created the constraint, one that's much more modest than with something like a Vampire puzzle. It's good introductory logic to these types of special-cell constraints and a great starting point for people who may be hesitant to try them.
Here are the other entries in the "Hot/Cold" series, for those interested:
Mexican Train (Killer/Kropki)
Here are some puzzles from other setters using the same constraint:
Hot and Cold by brennan77
Hot and Cold Cages by brennan77
An example puzzle will follow to better illustrate the rules.
Have fun!
Solve in f-puzzles!
Solve in SudokuPad!
Note: It is recommended you turn off the conflict checker during your solve (having a solution inputted provided unintentional spoilers during testing).
Solve in SudokuPad (with solution) ...beware of spoilers!
Solution code: The digits along column 2 and then column 8, read top-to-bottom.
Comments
on 18. April 2024, 15:40 by ChinStrap
Loved it! Seemed to have the same snag right at the end as others but besides that it was great!
on 1. June 2023, 23:02 by sacklunch
I really enjoy this ruleset. I recommend brennan77's earlier puzzles if you haven't tried them.
Thanks to VKP for setting and sharing this one!
on 1. June 2023, 12:37 by OldCaptainWZJ
Very nice flow, but I didn't see the easier logic at the end so I kinda just tried until it works. Still great overall.
on 1. June 2023, 06:37 by MatthewDonovan
Nice puzzle, thank you
on 26. May 2023, 13:09 by Yann
Awesome puzzle, this hot/cold constraint is so fun!
Unfortunately I totally messed my solve up by not spotting some obvious deductions and found some weird logic, but it still ended up solving nicely. Also, LMD thinks of this as the easiest 100% puzzle in the portal, so congrats on that achievement (I don't totally agree with it, for example digital rain is easier imo). Thanks for setting this!
on 22. May 2023, 23:01 by Christounet
The logic recolving around box 5 and in each killer cage is a lot of fun ! And the puzzle a lot easier than it would seem considering the rules. Thanks !!
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EDIT: That seems to be the popular consensus with the puzzles I set - they look a lot more daunting then they really are. Glad you enjoyed! -- VKP
on 3. May 2023, 05:09 by dennischen
good stuff, especially in box 5. thanks!
on 27. April 2023, 20:08 by brennan77
Loved it! Wish i had thought of that lol
EDIT: Thank you! still plenty of logical space to explore... Kropki dots? Cloned regions? (someday I will manage to crack the German Whisper puzzle) - VKP
on 5. April 2023, 22:27 by Slink
Great puzzle, the whole logic chain was a joy to work through.
on 1. April 2023, 15:50 by Paquet Voleur
Thanks for adding your own take on this very interesting constraint. I absolutely loved your box 5!
Thank you for your solve! I really think this constraint is deserving of more attention, hopefully it gets a bit more traction. - VKP
