With our graph construction stuff out of the way, we can write a simple function that initializes a brand-new game of Grand Theft Wumpus:

(defun new-game ()
    (setf *congestion-city-edges* (make-city-edges))
    (setf *congestion-city-nodes* (make-city-nodes *congestion-city-edges*))
   (setf *player-pos* (find-empty-node))
    (setf *visited-nodes* (list *player-pos*))
    (draw-city))

There are two new functions here. One, the find-empty-node function , ensures that the player doesn’t end up on top of a bad guy right at the beginning of the game. Here’s the code for that function:

(defun find-empty-node ()
   (let ((x (random-node)))
     (if (cdr (assoc x *congestion-city-nodes*))
         (find-empty-node)
          x)))

The find-empty-node function is pretty simple. First, it picks a random node to consider as the player’s starting position. Then it checks whether it is a completely empty node . If there’s stuff in that node, it simply calls itself again, trying another random spot .

The other new function in our new-game command is draw-city, which we’ll write next.