lisp lab 3

gistfile1.lisp

;1
(defun fib-r (n)
    (cond
      ( (eql n 1) 1)
      ( (eql n 2) 2)
      (t (+ (fib-r (- n 1)) (fib-r (- n 2))))
    )
  )

(defun fib-i (n)
  (do ((i n (- i 1))
    (old 1)
    (new)
    (result 1))
  ((< i 2) result)
  (setf new (+ result old))
  (setf old result)
  (setf result new)
    ))
;2

(defun len-r (lst)
  (if (NULL lst)  
    0
    (+  (len-r (cdr lst)) 1) 
  )
  )
;3
(defun sqr-sum (m n )                             
  (do ((i m (+ i 1)) (s 0 (+ s (* i i)))) ((= (+ n 1) i) s))
 )
;4
(defun gcd-r (a b)
  (if (= b 0) a (gcd-r b (mod a b))))

(defun lcm-r (a b)
  (/ (abs (* a b)) (gcd-r a b))
)
;5
(defun num-sum (lst)
  (if (numberp lst) lst (if (not (atom lst)) (+ (num-sum (car lst)) (num-sum (cdr lst))) 0) )
)
;6
(defun rm-item (itm lst)
  (if (not (null lst))
    (if (not(equal itm (car lst)))
      (cons (car lst) (rm-item itm (cdr lst)) )
      (rm-item itm (cdr lst))
    )
    ()
  )
)

;7
(defun item-count (itm lst)
  (if (not (null lst))
    (if (equal itm (car lst))
      (+ 1 (item-count itm (cdr lst)) )
      (item-count itm (cdr lst))
    )
    0
  )
)


(defun simp-list (lst lst2)
  (if (atom lst)
    (if (null lst) lst2 (cons lst lst2))
    (append (simp-list (car lst) lst2) (simp-list (cdr lst) lst2) )
  )
)
;8
(defun list-max (lst)
  (apply 'max (simp-list lst ()))
)


;9
(defun reverse-all (lst)
  (if (null lst) 
    nil
    (append (reverse-all(cdr lst)) (list (if (listp (car lst)) (reverse-all (car lst)) (car lst) )  ))
  )
)