Logic Masters Deutschland e.V.

Knights of the orthoganally-connected-snake table

(Published on 23. June 2021, 07:30 by SirSchmoopy)

I wanted to try making a snake/sudoku puzzle that required the knight's moves to complete the path of the snake, and this was the result after lots of trial and error. Please let me know what you think of this ruleset. I have only recently started setting sudoku puzzles and would appreciate any and all feedback you might have.

Basic rules:

  • Normal sudoku rules apply.
  • Normal antiknight rules apply. Identical digits may not be a knight's move (in chess) away from each other.
  • Normal killer rules apply. Digits in a cage do not repeat and sum to the total indicated in the top left corner
  • The digit in the grey square is even.
  • The inequality sign points to the lesser of the two digits.

Knight/snake rules:

Draw an orthoganally connected snake that satisfies the following criteria:
  • The head and tail of the snake are on the yellow shaded cells.
  • The snake does not touch itself, even diagonally
  • The clue outside the grid shows the sum of all snake cells in that row.

The blue cells are 'knight' cells and satisfy the following criteria:
  • Each digit from 1-8 appears in exactly one knight cell
  • Knight cells are not part of the snake.
  • The digit on a knight cell indicates the number of snake cells that are exactly one knight's move (in chess) away from the knight cell.
  • This count DOES NOT include snake cells seen by the knight cell by normal sudoku rules, unless that cell is also exactly one knight's move away. (So a snake cell that is a knights move away and in the same box would count towards the knight cell's total, but a snake cell that is on the same row or column as the knight cell would not). If this still isn't clear, see the examples below with some valid knight cell counts.

The red cells are snake cells, but similar to knight cells, their digit is also the count of how many snake cells that are exactly one knight's move away.

Play on F-Puzzles

Example of the knight cell constraints:

To illustrate the knight's cell/given snakes cell's counting logic, all given digits in the example would be acceptable knight (blue)/given snake (pink) cells, assuming snake cells are red.

Solution code: row 7 + row 8 (ex: 123456789456789123)


Solved by ArchonE, VykkDraygo, 21Tallan
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Comments

on 25. June 2021, 18:34 by VykkDraygo
Awesome! Thanks for the updated grid, it was VERY helpful. Perfect, in fact.

Loved the solve. The snake was fairly easy to find, but the ending sudoku was a bit more tricky. It was nice that the puzzle didn't just give up as soon as the snake logic was finished. Great fun!

Last changed on 24. June 2021, 23:32

on 24. June 2021, 23:00 by VykkDraygo
I'm colorblind, as such I can't really understand the example. I also see that coloring in the f-puzzles link is slightly different from the image here. I'm guessing f-puzzles is blue and pink? Only the pink is VERY difficult for me to tell apart from the blue (nearly impossible without surrounding the cell with the opposite color). I'd just re-color it myself, but I'm not sure I am SEEING the colors on the image (I see three: yellowish, blue, and a pinkish red).

I appreciate any help in this regard! The puzzle looks interesting, so I am looking forward to solving it, if I can. :)

[SirSchmoopy] Edit - sorry for not making something more colorblind friendly!
Here's a hopefully better version.

actual grid :
https://f-puzzles.com/?id=yj57azna
The head and tail snake cells have circles. The given snake cells with (with valid counts) have squares, the knight cells have diamonds.

Here's a link to an example. snake cells have diamonds and all given digits would be valid counts (either for a snake cell/knight cell)

https://f-puzzles.com/?id=yjtj8r2k

I'm not sure if this is any better, but hopefully it's at least unambiguous enough. If not here's all of the shaded cells from the starting grid:

snake head/tail: R1C3,R7C9

knight cells:R2C5,R2C8,R3C1,R3C7,R6C3,R6C4,R6C7,R7C7

given snake cells that are valid knight counts:R2C9,R4C3,R8C4

Edit: That's perfect! Thank you!

Difficulty:4
Rating:N/A
Solved:3 times
Observed:9 times
ID:0006QU

Puzzle variant Path puzzle

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