This is a problem set I wrote last year for a competitive programming course. Although it starts with a long story inspired by an XKCD What if?, the essential information only begins with the Pre-conditions heading.
Graphs, Computational geometry (such as Segment intersection, Jarvis’s march, and Graham scan)
It has a slightly different format of common competitive programming problems. I hope you find it as entertaining to solve as it was for me to write! :)
If you solve it, share the language of your solution and the time your program took to find the answer in the comments. ^^
Happy hacking, Diogo