LISP04 Vjezbe

;Vjezbe 4 - 3.11.

(defun duplanje (l)
    (mapcar #'(lambda (x) (list x x)) l)
)

;Posljednji zadatak

(defstruct pt
    x
    y
)

(defstruct ln
    pt1
    pt2
)

(defun udaljenost (p1 p2)
    (sqrt (+ (expt (- (pt-x p1) (pt-x p2)) 2) (expt (- (pt-y p1) (pt-y p2)) 2)))
)

(defun srida (l1)
    (make-pt :x (/ (+ (pt-x (ln-pt1 l1)) (pt-x (ln-pt2 l1))) 2) :y (/ (+ (pt-y (ln-pt1 l1)) (pt-y (ln-pt2 l1))) 2))
)

(setq points (list (make-pt :x 4 :y 4) (make-pt :x 6 :y 6) (make-pt :x 8 :y 8)))

(setq lines (list (make-ln :pt1 (nth 0 points) :pt2 (nth 1 points)) (make-ln :pt1 (nth 1 points) :pt2 (nth 2 points))))

(udaljenost (nth 0 points) (nth 1 points))
(udaljenost (nth 0 points) (nth 2 points))

(srida (nth 0 lines))
(srida (nth 1 lines))