Out of the Loop
(Published on 15. May 2025, 10:20 by oskode)
Here you go, a combination of Sudoku and Slitherlink with a twist on Region Sum Lines that I think work very well. I would estimate the difficulty to be somewhere around 3-4. Since it requires solving both the Sudoku and the Slitherlink, I went for the upper bound. Hope you enjoy!
Rules:
- Sudoku: Fill every cell with a digit from 1-9 such that no digit repeats in any row, column or 3x3 box.
- Slitherlink: Draw a loop along the edges of some cells. The loop does not branch, intersect nor touch itself. Four loop segments are already given (the red lines at R5C8/9, R7C1/2, R9C1/2 and R9C8/9).
- Circles: A digit in a circle indicate how many of its cell’s surrounding 4 edges are part of the loop. All circles are given. (Meaning a circled cell containing a 4 must be surrounded by 4 loop segments, while any non-circled cell containg a 4 must be surrounded by either 0, 1, 2 or 3 loop segments.)
- Region/Loop Sum Lines: Each light blue line is divided into at least two segments, and all segments of a line sum to the same total (this sum may be different for different lines). A line is segmented when crossing a region border and/or when crossing the loop.
- White Kropki: White dots separate digits with consecutive values, and the loop may not pass through them.
Click here to play online!
4x4 example: (Click here to play it)
The solution code for the example puzzle using in-loop digits in row 2 followed by in-loop digits in column 3 would be "42321"
Ratings and comments are very much appreciated. Thank you for playing!
Solution code: The digits inside the loop in both row 5 and column 9
Comments
on 13. July 2025, 17:28 by DukeBG
I have enjoyed the solve immensely, even though it took 1.5 hours. Slitherlink is one of my favorite types of puzzle and back in 2021 I was trying to combine it with sudoku myself, I would say unsuccessfully. This one works very well, though with regional sums forcing/denying the segments.
P.S. I would suggest changing "and/or" in the regional sums rules to just "and". Both crossing the loop and crossing a sudoku box splits the sums, "and" would be correct. My first thought was that "or" means there are sums that go across either the loop or the boxes in some places, but that would make it unsolvable. If "or" is there to mean "or both"... I think it's self evident.
on 16. May 2025, 00:16 by Exigus
Very nice. Struggled a bit with the loop but got there in the end. Thanks!
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Glad you pushed through, thanks for playing!
on 15. May 2025, 17:17 by Tilberg
Wundervoll!
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Thank you!
