While I appreciate efficient algorithms, I really feel like this kata was sufficiently complex without the last test (at least for the Java version) for the given difficulty rating, but maybe i'm just being salty because it took me so much longer to optimize than come up with the initial solution (which, for me, was still a little tricky).

Class kata was nice, however I'm wondering why the Java version didn't have the test case written out already, seems like just a waste of everyone's time to have the tests cases written into the description but not written into the test section.

Very nice solution, how quickly I look for programatic solutions over mathamatical ones... good job!

I think the ordering should stay the same in the end result. If you tell someone directions and say "go east, then north" that isn't the same as saying "go north, then east". What if there is no road to the north from the starting point?