Boundary Conditions
(Published on 19. May 2026, 07:53 by balpha)
Normal Sudoku rules apply.
Draw a path that only moves orthogonally, doesn't branch, doesn't intersect, overlap, or touch itself orthogonally, and whose two ends are the cells with the stars.
Region sum line: 3x3 box borders divide the path into segments. All segments have the same sum.
Yin Yang: The path cells and the non-path cells each form an orthogonally connected region, and every 2x2 area contains cells from both regions.
Kropki dots:
If two digits are separated by a black dot, one is double the other, and they are in different regions.
If two digits are separated by a white dot, they are consecutive, and they are in different regions.
Solution code: Row 3
Comments
on 14. July 2026, 13:16 by wuc
2.5* to 3* to me. Great puzzle thx.
on 12. July 2026, 21:39 by wuc
2.5* to 3* to me. Great puzzle thx.
on 27. May 2026, 11:06 by VitP
any yin-yang puzzle is automatically level 2, and almost certainly level 3, AT LEAST, simply by virtue of being yin-yang. add in the additional complexity of THIS rule set and initial conditions, and we are looking at a LIKELY level 4.
claiming "it's level 1" is simply absurd.
in the event, anyone who has a good understanding of yin-yang AND pathing puzzles AND basic sudoku AND all the other elements that are in this puzzle will find this "very easy". but isn't that just exactly the definition of an "experts only" puzzle (level 3) ?
[balpha:] I tend to agree, I had similar thoughts, which is why gave this three stars. The Y-Y part is on the easier side though, so I can understand that the majority went with two. It's not an exact science after all :)
on 19. May 2026, 21:52 by dzamie
That was rather pleasant. Forcing the YY to not fork wound up introducing a couple uncommon bits of logic.
[balpha:] Thanks for the nice feedback!
on 19. May 2026, 18:14 by Snookerfan
Very pleasant and approachable puzzle, probably 1 to 2 stars with a little challenge near the end. Thanks!
[balpha:] Thank you! Yes, consensus seems to be 2*.
on 19. May 2026, 09:33 by Reisen
The construction is very nice! One knows the basic restriction of Yin Yang can just find how to solve it easily :)
[balpha:] Thank you! Indeed, the Yin Yang is the easier part.
