1 665c255d 2023-08-04 jrmu (defun good-count-pairs (x)
 2 665c255d 2023-08-04 jrmu   (let ((pairs-table (make-hash-table :test #'eq)))
 3 665c255d 2023-08-04 jrmu     (labels (
 4 665c255d 2023-08-04 jrmu 	     (traverse-count (x)
 5 665c255d 2023-08-04 jrmu 	       (cond
 6 665c255d 2023-08-04 jrmu 		 ((not (consp x)) 0)
 7 665c255d 2023-08-04 jrmu 		 ((gethash x pairs-table) 0)
 8 665c255d 2023-08-04 jrmu 		 (t
 9 665c255d 2023-08-04 jrmu 		  (setf (gethash x pairs-table) 1)
10 665c255d 2023-08-04 jrmu 		  (+ (traverse-count (car x))
11 665c255d 2023-08-04 jrmu 		     (traverse-count (cdr x))
12 665c255d 2023-08-04 jrmu 		     1)))))
13 665c255d 2023-08-04 jrmu       (traverse-count x))))