Logic Masters Deutschland e.V.

This week's prompt from scojo is about german whispers and parity lines. I decided to create a yin yang puzzle where one half of the shading acts as a whisper line and the other half as a parity line. Enjoy!

• Sudoku: Normal Sudoku rules apply.
• Yin Yang: Shade some cells so that all shaded cells are orthogonally connected and all unshaded cells are orthogonally connected. No 2x2 area of the grid can be completerly shaded or completely unshaded.
• Shaded Whispers: Orthogonally adjacent shaded digits differ by 3 or more.
• Unshaded Parity Line: Orthogonally adjacent unshaded digits have an odd sum.
• Internal X-Sums: A digit N in a cell containing a number Z in its top left corner is unshaded and indicates that that cell sees N unshaded cells in the row and column combined including itself, and that those digits sum to Z. Shaded cells block vision. x and y are integers.

Example Puzzle

Here is an example puzzle with the same rules except there are no parity restrictions on unshaded cells. If two shaded cells are orthogonally connected (touch on an edge), they differ by 2 or more. Both clues are in unshaded cells. The 5 clue sees itself (r2c2) and the cell directly below it (r3c2). The digits in those cells add to 5 (2+3). The 10 clue sees itself (r3c4), the 2 cells to the left (r3c2, r3c3) and the cell above (r2c4). The digits in those cells add up to 10 (1+3+2+4). Unlike ordinary X-sums, internal X-sums may include repeated digits.