Logic Masters Deutschland e.V.

Sometimes a constraint is beautiful both visually and logically, and a skyscraper line fits that perfectly! I plan to make more use of them in the future.

Rules:

- Normal sudoku rules apply.

- Skyscraper Lines - A digit on a diamond indicates the number of visible skyscrapers along its line (not including itself) from that digit's direction of view - digits may repeat along the line if allowed by other rules. Example: If there is a diamond with a value of 4, a legal string could be 2356236, since the first 6 hides everything behind it on the line, including the next 6.

- Dutch Whispers - each digit on an orange Dutch Whisper line must differ in value by at least 4 from its neighbor on the line.

- XV sums - digits separated by a V sum to 5; digits separated by an X sum to 10. No negative constraint.

- Ratio Kropki dots - digits separated by a black Kropki dot have a value ratio of 1:2. No negative constraint.

Solve on Sudokupad.