;; $Header$
;; $Locker$

;; DESTRU -- Destructive operation benchmark
			
(defun destructive (n m)
  (declare (type fixnum n m))
  (let ((l (do ((i 10. (the fixnum (1- i)))
		(a () (push () a)))
	       ((= (the fixnum i) 0) a)
	     (declare (type fixnum i)))))
    (do ((i n (the fixnum (1- i))))
	((= (the fixnum i) 0))
      (declare (type fixnum i))
      (cond ((null (car l))
	     (do ((l l (cdr l)))
		 ((null l))
	       (or (car l) 
		   (rplaca l (cons () ())))
	       (nconc (car l)
		      (do ((j m (the fixnum (1- j)))
			   (a () (push () a)))
			  ((= (the fixnum j) 0) a)
			(declare (type fixnum j))))))
	    (t
	     (do ((l1 l (cdr l1))
		  (l2 (cdr l) (cdr l2)))
		 ((null l2))
	       (rplacd (do ((j (floor (the fixnum (length (car l2))) 2) 
			       (the fixnum (1- j)))
			    (a (car l2) (cdr a)))
			   ((zerop (the fixnum j)) a)
			 (declare (type fixnum j))
			 (rplaca a i))
		       (let ((n (floor (the fixnum (length (car l1))) 2)))
			 (cond ((= (the fixnum n) 0) (rplaca l1 ())
				(car l1))
			       (t 
				(do ((j n (the fixnum (1- j)))
				     (a (car l1) (cdr a)))
				    ((= (the fixnum j) 1)
				     (prog1 (cdr a)
				       (rplacd a ())))
				  (declare (type fixnum j))
				  (rplaca a i))))))))))))

(defun testdestru ()
  (print (time (destructive 600 50))))
