Ok, I am flummoxed by this. I've been working on this for a couple of weeks and have given things several passes, and have tried to optimize things as best I can, but I am still getting either wrong answers or time-outs. My approaches have included the following steps to try to minimize complexity: * Eliminate "worthless" nodes, replacing them with roads of equivalent length. * Establishing optimal road-connections between all nodes. * Using BitSets to hold the "fish" data, and only running checks for completion when a path containing a new set of fish is discovered.

I see that the difficulty of this is marked as only "moderate," so I assume that there may be some trick to this. Something that would be taught in a course on algorithms, perhaps? If someone could point me toward an online resource that I can use to understand useful tactics for approaching this problem, I would really appreciate it.