Fillmat-doku
(Published on 12. January 2024, 21:48 by yttrio)
This puzzle was created for MrDanH as part of the 2023 Secret Santa exchange on the CTC Discord, and is posted here with their permission. One puzzle type they mentioned in their bio was Fillmat, which I had not heard of before. It ended up working surprisingly well as a Sudoku hybrid puzzle. I created a 4x4, 6x6, and 9x9 with the rule set, with the 9x9 presented here (along with links to the 4x4 and 6x6). I have the difficulty initially listed as 5 stars, though it may be on the easier side of 5 stars.
Rules:
Normal Sudoku rules apply.
Fillmat: Divide the entire grid into regions, each region a one-cell-wide straight line of 1-4 orthogonally adjacent cells. Two regions of the same size may not share an edge. Region borders may not form any four-way intersections. In other words, any 2x2 box may not contain four different Fillmat regions, as those would meet at a single corner.
The digit inside a cell marked with a circle must be equal to the length of the Fillmat region which contains that cell.
If a cell has a given number in the upper left corner, then the digits in the Fillmat region which contains that cell must sum to that number.
Clues can be anywhere in the Fillmat region. Multiple clues may be in the same Fillmat region.
6x6 Example:
The image below shows a sample 6x6 puzzle and solution with the same rule set.
Play the example 6x6 in SudokuPad.
Play a bonus 4x4 example in SudokuPad.
Solution code: Row 9 with hyphens separating Fillmat regions (ex: 1234-56-7-89)
Comments
on 3. February 2024, 18:10 by mdjvz
I truly enjoyed it
on 20. January 2024, 02:24 by damasosos92
Almost miraculous grid!
on 15. January 2024, 15:36 by Myxo
Wonderful!
on 15. January 2024, 14:12 by gfoot
Really nice puzzle - great satisfying flow, and not too hard I think
on 15. January 2024, 08:49 by femto113
Way too much fun to be 5 stars. Maybe 3.5? Not hard so much as novel.
on 15. January 2024, 04:04 by Agent
Excellent puzzle! Very smooth.
on 14. January 2024, 23:56 by RedBarchetta
Just under 4 hours!! Yes!!! That's a win for me. I tried the 4x4 to understand it and was overwhelmed. I never thought I'd solve this 9x9.
I stared and started and found how some logic worked. After an hour I had broken it. I misapplied the 4-corner region rule. I thought a pair of 1-4 corners or 2-3 corners was allowed. Once I understood that rule it really was a powerful tool.
Second attempt I had bad logic halfway through. Third attempt I got mostly done. I got to the end of the coloring and knew that sudoku was next. I was sure some cells would be impossible to figure out. But then 789 triples magically showed up, other triples showed up that had to be maximized, and it just felt like such a rush!
I solved the puzzle but still had some coloring to do. So I knew something was wrong. And when the solution called for correct regions, I went back, found the error, and felt a nice calm and satisfaction, such that I'm done sudoking for a week - got my fill ! ;)
Long story short - too late - amazing puzzle! Thanks for the set and for sharing! I have set only a few and can't even imagine setting this thing. Well done, thanks again!
on 14. January 2024, 21:46 by mihel111
Great puzzle. Great logic path.
Well done yttrio.
on 13. January 2024, 21:41 by bansalsaab
Great concept and execution.
on 13. January 2024, 18:19 by hoopsie
Very slow and methodical. Start for me felt to be the easiest and then it got harder and I had to be very careful all the way to the end. Loved the puzzle though throughout
on 13. January 2024, 14:18 by h5663454
Hmm...it's pretty good. Except for the beginning, which is a bit bluffing, the average difficulty of the rest of the puzzles is only 3.5-4 stars...well, as far as I'm concerned.
on 13. January 2024, 13:07 by Nordy
Awesome geometry! Tricky, but oh so rewarding. Although some steps are hard, there is always something to think about, which keeps things exciting.
on 13. January 2024, 02:11 by SirWoezel
Hard, but very enjoyable too. Agree that it's noy quite 5 stars.
on 13. January 2024, 01:31 by yttrio
Slight rules clarification.
