Logic Masters Deutschland e.V.

I've recently enjoyed IcyFruit's Lighthouse puzzles (or at least watching Simon solve them on Cracking the Cryptic!) - this is my own take on them, combining them with my personal favourite rule of yin-yang...

Solve in SudokuPad

Sudoku: Normal sudoku rules apply.

Yin-Yang: Fill the grid with light and shade. All light forms a single orthogonally connected area; all shade forms a single orthogonally connected area. No 2x2 area is all light or all shade.

Lighthouses, Darkhouses:

• Rectangles in the light are lighthouses. They count the number of cells strictly smaller than themselves, NOT including themselves, which they see orthogonally IN THE LIGHT. Any digit larger than the lighthouse blocks line of sight; any digit in the shade also blocks line of sight.
• Rectangles in the shade are darkhouses. They count the number of cells strictly larger than themselves, NOT including themselves, which they see orthogonally IN THE SHADE. Any digit smaller than the darkhouse blocks line of sight; any digit in the light also blocks line of sight.
• Complete Set: Between them, the light houses and dark houses form a complete set of the digits 1 through 9.

Gradients: Digits on grey gradient lines strictly increase from one end to the other, but you must determine which way. Additionally, every gradient line has at least one light cell and at least one shade cell somewhere along its length.

Seeing Circles: Circles count the number of cells of the same colour (light or shade) that they see orthogonally, including themselves. The other colour blocks line of sight. ALL circles are given.