Question

Write a LISP program to play either the game "Connect Three" on a size 4x4 game board.

Your program must use min-max search and should be invoked by the function call:

> (connect-3)

The game is single player, human vs the computer AI.

Answer 1

;;;; @file connect4.lisp
;;; Variable difficulty Connect 4
;;; A verison of the popular board game which involves an AI player
;;; vs. one human player.

(defun load-relative(filename)
   "Loads files using relative file paths."
  
; Turn off load and compile messages.
   (setf *load-verbose* nil)
(setf *load-print* nil)
(setf *compile-verbose* nil)
(setf *compile-print* nil)

; Compiles and loads relative file paths.
(load (compile-file (merge-pathnames filename *load-truename*))))

;; Ensure necessary global variables are set to supress potential compiler warnings.
(defun reset-game()
(setf game '())
(setf first 0)
(setf difficulty 0)
(setf move-positions '())
(setf win nil)
(setf gameover nil)
)

(defvar move-positions)
(defvar difficulty)
(defvar first '())
(defvar game '())
(defvar firstElem)
(defvar *compMoves*)
(defvar *playerMoves*)
(defvar *oponent*)
(defvar *win*)
(defvar testList)
(defvar winDiagonalDown)
(defvar winDiagonal_up)
(defvar winHorizontal)
(defvar winVertical)
(defvar win)
(defvar firstA)
(defvar firstB)
(defvar nextElem)
(defvar newA)
(defvar newB)
(defvar input)
(defvar play)
(defvar ai-last-move)
(defvar gameover)

; Call reset-game to ensure clean vars.
(reset-game)

;; ------------------------------ LOAD THE NECESSARY FILES ------------------------------
(let ((*error-output* (make-string-output-stream)))
;; Compile & load helper functions.
(load-relative "inc/helper.lisp")

;; Compile & load AI engine file.
(load-relative "inc/ai.lisp")

;; Compile & load output file.
(load-relative "inc/output.lisp")

;; Compile & load file that checks gameplay for wins.
(load-relative "inc/winCheck2.lisp")

;; Compile & load helper main program control file.
;; Load main.lisp last, so it has all its dependencies.
(load-relative "inc/main.lisp")

;; Print compile errors to file, rather than to the std-out.
(with-open-file (str (merge-pathnames "tmp/compile.log" *load-truename*)
:direction :output
:if-exists :append
:if-does-not-exist :create)
(format str (concatenate 'string "~%Compile Time " (write-to-string (get-universal-time))
" Results:~%------------------------------------------------------~%"
(get-output-stream-string *error-output*)) "~%~%")))

;; --------------------------- CALL MAIN AND EXECUTE PROGRAM ----------------------------

;;; If main is specified outside of a function nothing is required here. If specified
;;; inside a function then call the function. Ex: (main).