This preview has intentionally blurred sections. Sign up to view the full version.
View Full DocumentThis preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: CS 188 Introduction to Fall 2009 Artificial Intelligence Midterm Exam INSTRUCTIONS • You have 3 hours. • The exam is closed book, closed notes except a onepage crib sheet. • Please use nonprogrammable calculators only. • Mark your answers ON THE EXAM ITSELF. If you are not sure of your answer you may wish to provide a brief explanation. All short answer sections can be successfully answered in a few sentences at most. Last Name First Name SID Login GSI Section Time All the work on this exam is my own. (please sign) For staff use only Q. 1 Q. 2 Q. 3 Q. 4 Q. 5 Q. 6 Total /11 /10 /12 /12 /13 /12 /70 2 THIS PAGE INTENTIONALLY LEFT BLANK NAME: 3 1. (11 points) Search Consider the following search problem, represented as a graph. The start state is S and the only goal state is G . Note that the following problems variously reference both tree search and graph search. For questions which require a heuristic, use the one given below. S A B D C E G 2 1 2 4 2 4 9 4 3 Heuristic S A B C D E G 6 6 4 1 10 (a) (1 pt) What path will BFS tree search return? (b) (1 pt) What path will UCS tree search return? (c) (1 pt) What path will UCS graph search return? (d) (2 pt) For UCS graph search , write the ordered sequence of states put on the closed list up to termination. (e) (1 pt) What path will greedy tree search return? (f) (1 pt) What path will A * tree search return? (g) (1 pt) Name a path that UCS expands (pops off the queue) but A * does not. (h) (2 pt) What path will A * graph search return? Hint: be careful. (i) (1 pt) Explain why your answer to part (h) is reasonable. 4 2. (10 points) Cooperative PacFamily Pacman is trying eat all the dots, but he now has the help of his family! There are initially k dots, at positions ( f 1 , ... f k ). There are also n PacPeople, at positions ( p 1 , ..., p n ); initially, all the PacPeople start in the bottom left corner of the maze. Consider a search problem in which all PacPeople move simultaneously ; that is, in each step each PacPerson moves into some adjacent position (N, S, E, or W, no STOP). Note that any number of PacPeople may occupy the same position. (a) (3 pt) Define the state space of the search problem. (b) (1 pt) Give a reasonable upper bound on the size of the state space for a general r by c grid. (c) (1 pt) What is the goal test? (d) (1 pt) What is the maximum branching factor of the successor function in a general grid? (e) (4 pt) Circle the admissible heuristics below (1/2 point for each mistake.) i. h 1 ( s ) = 0 ii. h 2 ( s ) = 1 iii. h 3 ( s ) = number of remaining food / n iv. h 4 ( s ) = max i max j manhattan( p i , food j ) v. h 5 ( s ) = max i min j manhattan( p i , food j ) vi. h 6 ( s ) = min i max j manhattan( p i , food j ) vii. h 7 ( s ) = min i min j manhattan( p i , food j ) viii. h 8 ( s ) = max( h 3 ,h 7 ) ix. h 9 ( s ) = min( h 3 ,h 4 ) x. h 10 ( s ) = Solve the singleagent food search problem for each PacPerson individually from their current position. Return the minimum of these divided by n . NAME:...
View
Full
Document
This note was uploaded on 04/16/2010 for the course COMPUTER S 188 taught by Professor Abbel during the Fall '10 term at Berkeley.
 Fall '10
 Abbel

Click to edit the document details