Between a Relative and a Stranger
(Published on 30. September 2024, 00:47 by Elytron)
Solve with SudokuPad.
Rules:
- Normal Sudoku rules apply.
- Draw a one-cell-wide snake of orthogonally connected cells. The snake may touch itself diagonally but not orthogonally and must visit all boxes exactly once.
- A digit on the snake, that is not an endpoint, is coprime to exactly one of its snake-neighbours, meaning their greatest common factor is 1.
- The two endpoints of the path contain the same digit, and exactly one of them has a coprime snake-neighbour.
- Cells separated by a white dot contain consecutive digits AND are not on the snake.
- Clues outside the grid indicate the sum of the digits along the indicated diagonal. Digits can repeat along the diagonal if allowed by other rules.
Solution code: The left-most snake-digit of each row from top to bottom, where 0 denotes there is no snake-cell.
Comments
on 5. July 2025, 03:54 by konjecture
Amazing how restrictive the ruleset actually is. Really clever
on 8. June 2025, 19:40 by Playmaker6174
Dayum, what a rewarding puzzle till the very end!
Quite certainly felt like 4/5 diff for me overall because of the snake construction, but it's surprisingly cool to discover the implications of the snake concept and how it works on the entire grid :)
on 23. March 2025, 20:47 by QuiltyAsCharged
Great puzzle. I found it really challenging at a few spots to disambiguate between options, but there is a logical way through. I enjoyed figuring out the implications of the coprime snake rules.
on 30. September 2024, 12:56 by Elytron
Made the rules more consistent.
on 30. September 2024, 12:52 by lmdemasi
Lovely construction, and several very satisfying "aha" moments.
on 30. September 2024, 08:15 by Elytron
Slightly changed the wording of the rules again
on 30. September 2024, 02:12 by Elytron
Changed the wording of the rules
