Logic Masters Deutschland e.V.

To Christmas 2023 some eager puzzlefriends have again arranged a group in which everybody had to make anonymously a puzzle for someone else. These puzzles are now presented one after the other here in the portal.

The gnomes are beside themselves with anticipation, for their Magic Yuletide Forest is finally going to have its own train line. Those points where the train is to pass particularly picturesque attractions have already been marked on the map. The train will pass straight through these points, so that visitors will have enough opportunity to admire the wonders of the forest. All that’s missing is the exact route the train will take.
The somewhat over-eager Schlampel begins to sketch a line on the map. „Hold it, hold it!“, comes the voice of their environmental protection officer, Tümpel. „Have you completely forgotten the requirements?“ „Whaddya mean?“, asks Schlampel, „I’ve sketched in a top-notch loop — no crossings and with an orderly orthogonal sequence from one cell to the next.“ „Granted“, admits Tümpel, „but you didn’t take the protected zones into account!“
The other gnomes are mystified – what protected zones? Tümpel explains: „In each of these marked areas there is exactly one protected zone, that spreads over orthogonally connected squares. The train must not traverse such zones.“ „Um ok“, says Simpel, „but how are we supposed to know where exactly the protected zones are located?“
„Well, that’s simple“, Tümpel retorts, „Two protected zones cannot touch across area borders, and protected zones in neighboring areas must be of different sizes. It is nevertheless still possible to build the train line – otherwise I’d never have approved the project.“
Simpel still looks perplexed, but Lampel and Knobel have understood. They grab a pen and begin to sketch in the protected zones and the train line on the map.
Soon, the path of the train line is determined, and construction can begin!

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