The question here is to find a path from A(rad) to B(ucharest). I’ll be using the initials of the cities in the picture instead of their full names.

Some ground-rules: we’re traversing in alphabetical order. And traversal must stop once the goal node has been generated, not expanded. This last part is where I feel like I’m not completely understanding what is being asked.

**So the solution given is: Arad, Sibiu, Timisoara, Zerind, Fagaras, Bucharest.**

What I think the solution is as follows: we’re at A so A has been “generated”. And then we expand A, giving us: A, S, T, Z. Since the goal node hasn’t been generated we start with S. Expanding S gives us F and R (no goal node yet) and then we expand T giving us L following which Z is expanded giving us O. So far we have A, S, T, Z, F, R, L, O. Now, going alphabetically, we go to F for expansion. This gives us B and this is where the traversal should stop.

**So my solution is A, S, T, Z, F, R, L, O, B.**

Can you tell me where I’m going wrong and why the given solution (as opposed to my solution) is correct?