Artificial Intelligence Problem solving by searching CSC 361 Prof. Mohamed Batouche Computer Science Department CCIS – King Saud University Riyadh, Saudi Arabia batouche@ccis.edu.sa

Problem Solving by Searching Search Methods : Problem Solving by Searching Search Methods : Uninformed (Blind) search Tutorial II

Search Methods River boat Farmer, Wolf, Duck and Corn Consider the River Problem: A farmer wishes to carry a wolf, a duck and corn across a river, from the south to the north shore. The farmer is the proud owner of a small rowing boat called Bounty which he feels is easily up to the job. Unfortunately the boat is only large enough to carry at most the farmer and one other item. Worse again, if left unattended the wolf will eat the duck and the duck will eat the corn. How can the farmer safely transport the wolf, the duck and the corn to the opposite shore? Solve this problem using BFS. Do not expand repeated stated. Farmer, Wolf, Duck and Corn boat River

Search Methods A C D E F B G H I J K L M N O P Q R S T U V W X Y Z Problem 2: Given the following state space (tree search), give the sequence of visited nodes when using BFS, DFS, and IDS. A C D E F B G H I J K L M N O P Q R S T U V W X Y Z Initial state Goal state

A S B G C 10 1 5 5 5 15 Consider the following problem… We wish to find the shortest route from node S to node G; that is, node S is the initial state and node G is the goal state. In terms of path cost, we can clearly see that the route SBG is the cheapest route. However, if we let breadth-first search loose on the problem it will find the non-optimal path SAG, assuming that A is the first node to be expanded at level 1. Solve this problem using UCS.