Ch' 4 Informed Search

1
Ch. 4 Informed Search

• Supplemental slides for CSE 327
• Prof. Jeff Heflin

2
Class Exercise

• Use A to solve the 8-puzzle

goal state
initial state

• Choose a heuristic
• H1 The number of tiles out of place
• H2 Sum of distances of tiles from goal positions
• Ignore moves that return you to the previous state

3
A on 8-puzzle
Whether or not this node is expanded depends on
how you break ties. It could be expanded at any
time or not at all.
f033
1
Heuristic H1
f134
f134
2
3
f246
f224
f235
f246
4
f336
f336
f314
5
f426
f404
6
4
A on 8-puzzle
f044
1
Heuristic H2
f134
f156
2
f246
f224
3
f336
f336
f314
4
f426
f404
5