Based on the slow trickle of results pt2 was very hard. But, having now got a good result, its not that difficult, but getting to that solution/algorithm took a lot of brain power.

I hope todays is a little bit more relaxed.

yea becomes trivial if one uses a polygon library (I did too) but looking at the actual polygon, one can cook up some clever heuristics to do it quite quickly with some basic checks I think.