Пребарување

(defun run-breadth (start goal moves)
  (declare (special *open*))
  (declare (special *closed*))
  (declare (special *goal*))
  (setq *open* (list (build-record start nil)))
  (setq *closed* nil)
  (setq *goal* goal)
  (breadth-first moves))

;;; These functions handle the creation and access of (state parent)
;;; pairs.

(defun build-record (state parent) (list state parent))

(defun get-state (state-tuple) (nth 0 state-tuple))

(defun get-parent (state-tuple) (nth 1 state-tuple))

(defun retrieve-by-state (state list)
  (cond ((null list) nil)
        ((equal state (get-state (car list))) (car list))
        (t (retrieve-by-state state (cdr list)))))



(defun breadth-first (moves)
  (declare (special *open*))
  (declare (special *closed*))
  (declare (special *goal*))
  (cond ((null *open*) nil)
        (t (let ((state (car *open*)))
             (setq *closed* (cons state *closed*))

             (cond
    ;;; found solution: print path to it
        ((equal (get-state state) *goal*) (reverse (build-solution *goal*)))

            ;;; try next child state
                (t (setq *open*
                            (append (cdr *open*)
                                    (generate-descendants (get-state state)
                                                          moves)))
                      (breadth-first moves)))))))

(defun generate-descendants (state moves)
  (declare (special *open*))
  (declare (special *closed*))
  (cond ((null moves) nil)
        (t (let ((child (funcall (car moves) state))
                 (rest (generate-descendants state (cdr moves))))
             (cond ((null child) rest)
                   ((retrieve-by-state child rest) rest)
                   ((retrieve-by-state child *open*) rest)
                   ((retrieve-by-state child *closed*) rest)
                   (t (cons (build-record child state) rest)))))))


(defun build-solution (state)
  (declare (special *closed*))
  (cond ((null state) nil)
        (t (cons state (build-solution
                        (get-parent
                         (retrieve-by-state state *closed*)))))))

(defvar *initial* '((0 2) (4 0) ((2 1) (3 1) (2 3)) ((0 0) (3 3)))) ;; ((Px Py) (Kx Ky) ((D1x D1y) (D2x D2y)(D3x D3y)) ((Z1x Z1y) (Z2x Z2y)(Z3x Z3y)))
;(defvar *initial* '((0 2) (4 0) ((2 1) (3 1) (3 3)) ((2 2) (3 2) (2 3)))) ;; plus test primer

(setq king (car *initial*))
(setq queen (car(cdr *initial*)))
(setq ghostlist (car(cdr(cdr *initial*))))
(setq dragonlist (car(cdr(cdr(cdr *initial*)))))

(defun make-state (x y)
    (list x y)
    )
(defun safe (state)
    (cond
        ((eq (safeFromDragons dragonlist state) nil)  nil)
        ((or (< (car state) 0)(> (car state) 4)(< (car(cdr state)) 0)(> (car (cdr state)) 4)) nil)
        (t state)
        )
)

(defun safeFromDragons (dragonlist state)
    (cond
        ((null dragonlist) t)
        ((or (equal state (make-state (+ (car(car dragonlist)) 1)(car(cdr(car dragonlist)))))
         (equal state  (make-state (- (car(car dragonlist)) 1)(car(cdr(car dragonlist)))))
         (equal state  (make-state (car(car dragonlist))(+ (car(cdr(car dragonlist))) 1)))
         (equal state  (make-state (car(car dragonlist))(- (car(cdr(car dragonlist))) 1)))
         (equal state  (make-state (+ (car(car dragonlist)) 1)(+ (car(cdr(car dragonlist)))1)))
         (equal state  (make-state (+ (car(car dragonlist)) 1)(- (car(cdr(car dragonlist)))1)))
         (equal state  (make-state (- (car(car dragonlist)) 1)(+ (car(cdr(car dragonlist)))1)))
         (equal state  (make-state (- (car(car dragonlist)) 1)(- (car(cdr(car dragonlist)))1))))
             nil)
        (t (safeFromDragons (cdr dragonlist) state))
    ))
(defun gore (state)
    (safe (make-state (+ (car state) 1) (cadr state)))
)

(defun dolu (state)
    (safe (make-state (- (car state) 1) (cadr state)))
)

(defun levo (state)
    (safe (make-state (car state) (- (cadr state) 1)))
)

(defun desno (state)
    (safe (make-state (car state) (+ (cadr state) 1)))
)

(defun gore-desno (state)
    (safe (make-state (+ (car state) 1) (+ (cadr state) 1)))
)

(defun gore-levo (state)
    (safe (make-state (+ (car state) 1) (- (cadr state) 1)))
)

(defun dolu-desno (state)
    (safe (make-state (- (car state) 1) (+ (cadr state) 1)))
)

(defun dolu-levo (state)
    (safe (make-state (- (car state) 1) (- (cadr state) 1)))
)


(print(run-breadth king queen '(gore dolu levo desno gore-levo gore-desno dolu-levo dolu-desno)))