Solving problems by searching

Outline

Problem-solving agents

Example: Romania

Example: Romania

Problem types

Example: vacuum world

Example: vacuum world

Example: vacuum world

Example: vacuum world

Single-state problem formulation

Selecting a state space

Vacuum world state space graph

Vacuum world state space graph

Example: The 8-puzzle

Example: The 8-puzzle

Example: robotic assembly

Tree search algorithms

Tree search example

Tree search example

Tree search example

Implementation: general tree search

Implementation: states vs. nodes

Search strategies

Uninformed search strategies

Breadth-first search

Breadth-first search

Breadth-first search

Breadth-first search

Properties of breadth-first search

Uniform-cost search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Depth-first search

Properties of depth-first search

Depth-limited search

Iterative deepening search

Iterative deepening search l =0

Iterative deepening search l =1

Iterative deepening search l =2

Iterative deepening search l =3

Iterative deepening search

Properties of iterative deepening search

Summary of algorithms

Repeated states

Graph search

Summary