Lösungscode: Zeilen 6 und 9 des gelösten Rätels
am 27. März 2020, 16:16 Uhr von Circleconstant314
I figured this was a proof-of-concept, which is why I still rated the puzzle 'nice' — after all, you did manage to find an absolute minimal construction here.
am 26. März 2020, 19:21 Uhr von SlowLarry
The puzzle aimes for minimalism more than a smooth solution path - a proof of concept so to speak.
That being said, the general technique here would be to mark all excluded cells for a queen; rows, cols or boxes with few remaining options then often excluding further cells.
That done to the full extent should leave about three spots where a bifurcation between exactly two options is needed, the wrong option leading to a contradiction relatively quickly in each case.