smiley-nqueens.lisp

(defclass square ()
  ((state :initarg :state :accessor state) ;; -1 if queen, 0, 1, ... N otherwise
   (x :initarg :x :accessor x)
   (y :initarg :y :accessor y)))

(defmethod update-square ((self square) new-state)
  (if (!= (state self) -1)
      (incf (state self) new-state) ;; it's not a queen - update
      (setf (state self) 0))) ;; remove the queen

(defmethod get-state ((self square))
  (if (= (state self) -1)
      "Q"
      (state-self)))

(defmethod get-coord ((self square))
  (let ((coord (list (x self) (y self))))
    coord))


(defclass board ()
  ((n :initarg :n :accessor n)
   (queens :initarg :queens :accessor queens)
   (squares :initarg :squares :accessor squares)))

(defun make-board (n)
  (let ((squares (make-array (list n n))))
    (dolist (row n)
      (dolist (col n)
        (setf (aref squares row col) (make-square 0 row col))))))

(defun print-board (self)
  (let ((n (n self)))
    (format t "--------------------------------------------------------~%")
    (dotimes (row n)
      ;; not sure how numpy works so this is probably translated wrong
      (let ((a-row (make-array (list n 0))))
        (dotimes (col n)
          ;; this append is definitely wrong
          (setf a-row (append a-row (coerce 'string (get-state (aref (squares self) row col))))))
        ;; also wrong because i'm not sure what *a_row does
        (format t "~a~%" a-row)))
    (format t "--------------------------------------------------------~%")))