The document discusses the A* algorithm for pathfinding and problem solving. It introduces the A* algorithm and notes that it uses admissible heuristics, where the heuristic for any node never overestimates the true cost to reach the goal state. An example of an admissible heuristic is the straight-line distance, as it provides an optimistic estimate of reaching the goal.

1. 1
CSAL3243 : Artificial
Intelligence

2. 2
Lecture 6: A* Algorithm
Dr Tariq

3. A*
3

4. WORKING
4

5. 5

6. 6

7. 7

8. 8

9. 9

10. 10

11. 11

12. 12

13. 13

14. 14

15. 15

16. • Admissible heuristics
• A heuristic h(n) is admissible if for every node n, h(n) ≤
h*(n), where h*(n) is the true cost to reach the goal state
from n
• e.g., Straight-Line Distance an admissible heuristic never
overestimates the cost to reach the goal, i.e., it is
optimistic
16