For the manhattan distance heuristic--no you don't consider obstacles (if you do, you will be getting the "real" distance). The whole point of the heuristic is to relax the problem (and in this case you relax by ignoring obstacles).
On Mon, Feb 16, 2009 at 11:10 PM, Todd MacLeod <firstname.lastname@example.org> wrote:
I have a few questions about Homework #2...
1. For part A, questions 3 and 4, you give us a link to a pdf. Must we do all the problems contained on this pdf?
2. Part A  (used in question 3 and 4) of the pdf asks some questions about the manhattan distance of a grid with obstacles. When counting the total moves for a given tile using manhattan distance, do we consider obstacles, or does the manhattan distance heuristic ignore obstacles, and go right over them? Perhaps a better way to ask this is given the grid in the pdf, what would be the total manhattan distance of a tile moved from A to F? Would it be 5 (which would avoid the obstacles) or would it be 3 (which ignores the obstacles.)