7. Refine our method of computing the heuristic value for a state of the
eight-puzzle so that the search algorithm of Figure 11.10 does not
make the wrong choice, as it did in the example in this section. Can
you find an example in which your heuristic still causes the search to
go astray?
8. Draw to the search tree produced by the best-fit algorithm (Figure 11.10)
in finding the route from Leesburg to Bedford. Each node in the search
tree will be a city on the map. Begin with a node for Leesburg. When
expanding a node, add only the cities that are directly connected to the
city being expanded. Record in each node the straight-line distance to
Bedford and use this as the heuristic value. What is the solution found by
the best-fit algorithm? Is the found solution the shortest route?