Ghost Algorithm

The original pacman seems to have had a fairly simple algorithm for ghost movements - at each intersection, they simply choose the direction that takes them closer to pacman in an absolute sense. Some modern games seem to use more sophisticated algorithms like the A* etc.

To begin with, I think I'm going to stick to tradition and use the simple logic, mixed with randomness. Lower difficulty levels will have a higher proportion of random decisions. I may work on a more sophisticated algorithm later on.