;; This code is written in FlooP. To run it, first open interpreter.scm
;; in DrRacket and type (start), then type (load-quietly "wondrous.txt")
;; at the ==> interpreter prompt.

(define procedure "wondrous?" (n)
  (block 0 begin
         (if (n = 0) then
             (quit block 0))
	 ((cell 0) <= 0)
         (mu-loop
          (block 1 begin
                 (print n)
                 (if (n = 1) then
                     (block 2 begin
                            (output <= yes)
			    (print "took" (cell 0) "steps")
                            (quit block 0)))
		 ((cell 0) <= ((cell 0) + 1))
                 (if ((remainder n 2) = 0) then
                     (block 3 begin
                            (n <= (quotient n 2))
                            (quit block 1)))
                 (n <= ((3 * n) + 1))))))

(define procedure "count-steps" (n)
  (block 0 begin
         (if (n = 0) then
             (quit block 0))
	 ((cell 0) <= 0)
         (mu-loop
          (block 1 begin
                 (if (n = 1) then
                     (block 2 begin
                            (output <= (cell 0))
                            (quit block 0)))
		 ((cell 0) <= ((cell 0) + 1))
                 (if ((remainder n 2) = 0) then
                     (block 3 begin
                            (n <= (quotient n 2))
                            (quit block 1)))
                 (n <= ((3 * n) + 1))))))

(define procedure "most-wondrous-up-to" (limit)
  (block 0 begin
         ((cell 0) <= 1)
         ((cell 1) <= 0)
         ((cell 2) <= 1)
         ((cell 3) <= 0)
         (loop limit times
               (block 1 begin
                      ((cell 1) <= (count-steps (cell 0)))
                      (if ((cell 1) > (cell 2)) then
                          (block 2 begin
                                 ((cell 2) <= (cell 1))
                                 ((cell 3) <= (cell 0))
                                 ))
                      ((cell 0) <= ((cell 0) + 1))))
         (print "most wondrous number found is" (cell 3))
         (print "which took" (cell 2) "steps")
         (output <= (cell 3))))