Final answer:
The A* algorithm does not always return an optimal solution, but it guarantees to find a solution if one exists. The quality of the heuristic function used in A* determines the optimality of the solution.
Step-by-step explanation:
The A* algorithm does not always return an optimal solution, but it guarantees to find a solution if one exists.
A* is an informed search algorithm commonly used in pathfinding and graph traversal. It uses a heuristic function to estimate the cost of reaching the goal from each explored node. However, the quality of the heuristic function directly affects the optimality of the solution.
If the heuristic function is admissible and consistent, meaning it never overestimates the actual cost and is consistent with the triangle inequality, respectively, then A* is guaranteed to return an optimal solution.