Normal sudoku rules apply.
Shade some cells such that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected and no 2x2 area is fully shaded or unshaded.
Digits in caged cells indicate how many cells of the same color (shaded or unshaded) are seen orthogonally from that position, including itself. The "other" color blocks vision.
Digits along a blue line have an equal sum N within each box it passes through. If a line passes through the same box more than once, each individual segment of such a line within that box sums to N separately. Different lines may have different values for N.
Have fun, leave a comment if you enjoy the puzzle!
Solution code: Row 4 followed by Row 6
on 12. August 2024, 16:33 by Cosinus
Love the whole series!
on 29. July 2024, 10:35 by wuc
Very clever setting (again). A bit harder to me but 3 star. Very cool to solve. Thx.
on 12. February 2024, 19:57 by Allagem
I think this is my favorite puzzle of the YYSL series! Discovering the yin-yang coloring was especially enjoyable this time around and there are many uniquely Region Sum + sight line deductions to be found. Bravo!
on 30. August 2023, 20:19 by Nemefish
Very fun puzzle. I am loving this series. It took me a little while to get momentum but every deduction feels reasonable and satisfying.
on 29. August 2023, 14:00 by Nylimb
Very nice combination of rules; thanks!