AoC day 10 B

(load "~/quicklisp/setup.lisp")
(ql:quickload "bit-smasher")
(defparameter *lens*
  (append (map 'list #'char-code "129,154,49,198,200,133,97,254,41,6,2,1,255,0,191,108")
          '(17 31 73 47 23)))

(defparameter *list*
  (loop for i upto 255 collect i))
(rplacd (last *list*) *list*)
(defparameter *lh* *list*)

(defparameter *skp* 0)

(defun reverseip (l len)
  (if (= len 0)
      l
      (let ((lt (nthcdr len l)))
        (rplacd (nthcdr (1- len) l) '())
        (loop
           for i from (1- (length l)) downto 0
           for j upto (1- (length l))
           do (if (or (< i j)
                      (= i j))
                  (return)
                  (rotatef (nth j l) (nth i l))))
        (nconc l lt)
        l)))

(dotimes (i 64)
  (dolist (len *lens*)
    (reverseip *list* len)
    (setf *list* (nthcdr (+ len *skp*) *list*))
    (incf *skp*)))

(let ((denseh '()))
  (dotimes (i 16)
    (setf denseh
          (nconc denseh
                 (list
                  (reduce #'bit-xor
                          (mapcar #'bit-smasher:bits<-
                                  (subseq *lh* (* 16 i) (+ (* 16 i) 16))))))))
  (format t "~{~a~}~%" (mapcar #'bit-smasher:bits->hex denseh)))