Logic Masters Deutschland e.V.

EDIT (00:30, 28/09/2025): On reflection, part of this puzzle only felt reasonable to me while setting because I had become very used to the logic, and is actually significantly fairer and improved by adding more given digits. You can't say I'm not trying to be a kinder constructor!

---

This is my response to Scojo's setting prompt as redeemed by Sotehr, which was to remake, or make a sequel to, an older puzzle. I chose The Postman Problem, as I really enjoyed the concept, and it's one of very few puzzles for which I have a crystal clear idea of what I'd do differently if I remade it.

Without wanting to give away too many spoilers, The Postman Problem has the feel of a two-part puzzle: the Skyscraper clues are sufficient to draw almost the entire loop, and the anti-kropki rule for the loop was simply selected as a way of resolving the remaining sudoku. I was very proud of the puzzle, but felt that it could've benefited from some more interaction between all elements of the ruleset for a more integrated solve path.

Thank you to Sotehr himself for testing a rather hastily-made first draft of this puzzle. It turns out that a week of experimenting yielded no improvements, so please enjoy that very draft!



SUDOKU:
• Fill every cell with a digit from 1-9;
• Digits may not repeat in a row, column or 3x3 box.

SKYSCRAPER CELLS:
• Some cells in the grid are Skyscraper cells;
• A digit in a Skyscraper cell represents that Skyscraper's height;
• A clue outside the grid shows how many Skyscrapers are visible in the indicated row or column from the direction of the clue, where taller Skyscrapers obscure the line of sight to shorter ones;
• A non-Skyscraper cell has a height of 0, i.e. it neither obscures the view nor is seen by a clue.

DUTCH WHISPER LOOP:
• Draw a loop in the grid, which may not branch or visit a cell more than once;
• The loop travels orthogonally with the exception of the bridge shown, which it traverses diagonally;
• The loop may not enter a Skyscraper cell (but does not have to visit every non-Skyscraper cell);
• The loop must visit exactly N cells in each Skyscraper's immediate neighbourhood (orthogonally or diagonally adjacent to the Skyscraper), where N is the digit in the Skyscraper;
• The loop is a Dutch Whispers line, i.e. adjacent digits on a line have a difference of at least 4.