Symmetric mountain sudoku
(Eingestellt am 27. Februar 2023, 04:21 Uhr von Nylimb)
Normal sudoku rules apply: Fill the grid with digits from 1 to 9, so that every row, column, and 3x3 box contains each of the 9 digits exactly once.
In addition, there is a mountain hidden in the grid. Its peak is at the 9 in the central box. The mountain consists of all cells which can be reached from the peak by repeatedly moving from a cell to an orthogonally adjacent cell containing a smaller digit. (See example below.)
In this puzzle, the mountain is rotationally symmetric: The cell at row R, column C is in the mountain if and only if the cell at row 10-R, column 10-C is in the mountain. (The digits in those cells may or may not be equal.)
You can solve this in Penpa or in the CTC-app.
As an example of the mountain definition, in the grid below, the mountain (which is symmetric) is shaded and a path is drawn in red from the peak to another mountain cell.
If you want to solve an easier puzzle of this type first, try Introduction to mountain sudoku. And if you like this puzzle, you might also like my other mountain sudokus.
Lösungscode: Row 1 and row 9.
Kommentare
am 13. Juni 2023, 23:56 Uhr von damasosos92
Probably your best mountain sudoku! Thank you so much! Added to favourites :D
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@damasosos92: Thanks for the comment. From the rating, it looks like other solvers agree with you.
am 20. März 2023, 01:49 Uhr von SimplePurpleFrog
I loved this puzzle, great logic unfolds smoothly. The symmetry is an interesting constraint.
am 1. März 2023, 23:31 Uhr von NIGHTCRAULER
I have very much enjoyed this mountain series. The symmetric constraint felt easier, though I think it's because I've gotten used to mountain puzzles through this series. Thanks for setting them all!
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@NIGHTCRAULER: I think you're right about this being easier. I hope the puzzles will eventually get enough solves to get difficulty ratings, so I'll know if other solvers agree.
am 1. März 2023, 03:29 Uhr von Allagem
I'm loving the mountain series! To be honest, I wasn't feeling the symmetric twist when I read the rules, but once I got into the puzzle, I understood the potential. This was actually a really fun puzzle and yet another creative and interesting twist on Mountain Sudoku!
