Final Lines Drawn by 2025
(Published on 15. December 2025, 07:04 by Kutsumi Hane)
Rules:
Normal Sudoku rules apply, requiring that each row, column, and 3×3 box contains the digits 1-9 exactly once. Additionally:
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·Dual-Property Lines:
The four lines forming the "2025" shape each satisfy exactly two of the following four properties:
(a) Coprime Line
Adjacent digits on the line must be coprime. The digit 1 is coprime with any digit.
(b) Region Sum Line
Each segment of the line within a box sums to the same value.
· For lines that pass through the same box multiple times, each pass is a separate segment.
(c) Renban Line
Digits on the line form a set of consecutive numbers in any order.
(d) Zipper Line
Each pair of orthogonally adjacent lines shares only one property, and these shared properties are all different.
Digits equidistant from the two ends of the line sum to the same value.
· For lines of odd length, the middle cell equals this sum.
· For closed-loop lines, one cell must serve as the reference cell, acting as both ends of the zipper.
· For closed-loop lines, one cell must serve as the reference cell, acting as both ends of the zipper.
·Local Extremes:
Cells marked with ● are strictly greater or less than all orthogonally adjacent neighbours.
Here you can solve the puzzle online:
Solve on SudokuPad
The difficulty is probably 5 stars. I wish you joyful solving!
The difficulty is probably 5 stars. I wish you joyful solving!
Hint:
· Knowledge of advanced techniques, such as X-Wing and Swordfish, may prove useful.
· When appropriate, carefully considering assumptions on unresolved cells can help advance the solve.
Solution code: Two "2"-shaped lines: digits along the line (starting at top-left), separated by "/".
Last changed on on 17. December 2025, 06:15
Solved by amaoto, mayiyang, kehan628, strangelyinsane, 72kchunshuai
Comments
on 17. December 2025, 06:15 by Kutsumi Hane
- Additional hints included.
- Rule formatting on the SudokuPad page has been revised.
