### COSC 387: Artificial Intelligence

Project 1
Fall 2010

Due: Wed, Sep 29 @ 10 P.M.
4 points

1. Write a function that uses the do form to find the minimum and maximum values in a list of numbers. The function should return these two values in a list. Do not use the min and max functions in your implementation.

2. Same problem as above, but use recursion.

3. Same problem as above, but use apply, min, and max.

4. Encode the following tree as a list assigned to a globally declared variable. Write two Lisp functions, preorder and postorder, that returns as a list the pre-order and post-order traversals of the tree passed in as the argument, respectively.

For example,

```> (preorder *tree*)
(O R E G O ... )
```

5. Encode the following graph using property lists. Write a Lisp function that, when given a start and an end node, uses depth-first search to return a path between them.

For example,

```>(dfs 'a 'g)
(A C F E G)

>(dfs 'f 'g)
(F E G)

>(dfs 'e 'c)
NIL
```
6. Develop a representation for a tic-tac-toe board. Write a function that, when given a board configuration as its argument, returns a list containing all of the next possible moves.

7. Tanimoto defined a heuristic evaluation function for tic-tac-toe boards as

f = 100A + 10B + C - (100D + 10E + F),

where

• A is the number of lines with 3 X's,
• B is the number of unblocked lines w/ 2 X's,
• C is the number of unblocked lines with 1 X,
• D is the number of lines with 3 O's,
• E is the number of unblocked lines w/ 2 O's, and
• F is the number of unblocked lines w/ 1 O.

Implement Tanimoto's heuristic evaluation function. That is, when given a tic-tac-toe board configuration, the function returns f.

Extra Credit (1 point each)

1. Conduct a timing study using your three implementations of the “min-max” function (items 1–3 above). Write a function that returns a list of 1000 random numbers. Write another function that generates 1000 such lists, giving each to the three implementations of the min-max function. Use the time function to determine how much time each implementation requires to process the 1000 lists. Which is faster? Why?

2. There are two possible ways to iterate through a list. One can use dolist or one can use dotimes, length, and nth. Using the functions above, iterate through 1000 lists of 1000 random numbers using both of these methods and time them. Which is faster? Why?

#### Instructions for Electronic Submission

In the header comments of the primary file, provide the following information:
```;;;;
;;;; Name
;;;; Platform: Windows, Linux (seva), etc.
;;;; Lisp Environment: clisp, gcl, cmucl
;;;;
;;;; In accordance with the class policies and Georgetown's Honor Code,
;;;; I certify that, with the exceptions of the course materials and those
;;;; items noted below, I have neither given nor received any assistance
;;;; on this project.
;;;;
```

You'll be using Blackboard to submit your assignments. Put everything in a zip file and upload it.

You must submit your project before 10 PM on the due date.

#### Plan B

If something goes wrong with Blackboard, then send your project as an attachment to an e-mail to me.