I think A* is solving a different problem than dijkstra's, since it requires an admissible heuristic to do any better than dijkstra's.
As long as you have an admissible heurustic, A* won't ever perform worse than dijkstra's.
As long as you have an admissible heurustic, A* won't ever perform worse than dijkstra's.
A* finds the shortest path from a node to a single other node. Dijkstra's finds the shortest paths from a node to all other nodes. If you use it as a search algorithm to find the shortest path to a single target, then yes, it's equivalent to A* with h(x)=0, but you're terminating Dijkstra's early (once your target is found) and not running the full algorithm.