Преобразование списка в множество, работа с деревьями

(defun dump-duplicates (w)
  (when w ((lambda (a d)
             (if (member a d)
                 (dump-duplicates d)
                 (cons a (dump-duplicates d))))
           (car w) (cdr w))))
 
> (dump-duplicates '(1 2 3 4 5 1 2))
(3 4 5 1 2)

(defun dump-duplicates (w &aux (a (car w)) (d (cdr w)))
  (when w (if (member a d)
              (dump-duplicates d)
              (cons a (dump-duplicates d)))))
 
> (dump-duplicates '(1 2 3 4 5 1 2))
(3 4 5 1 2)

(defun dump-duplicates (w)
  (when w (if (member (car w) (cdr w))
              (dump-duplicates (cdr w))
              (cons (car w) (dump-duplicates (cdr w))))))
 
> (dump-duplicates '(1 2 3 4 5 1 2))
(3 4 5 1 2)

(defun dump-duplicates (w)
  (cond ((null w) nil)
        ((member (car w) (cdr w)) (dump-duplicates (cdr w)))
        (t (cons (car w) (dump-duplicates (cdr w))))))
 
> (dump-duplicates '(1 2 3 4 5 1 2))
(3 4 5 1 2)

(defun add-in-tree (tree n)
  (cond ((null tree) (list n nil nil))
        ((> n (car tree)) (list (car tree) (cadr tree) (add-in-tree (caddr tree) n)))
        (t (list (car tree) (add-in-tree (cadr tree) n) (caddr tree)))))
 
==> add-in-tree
 
(setq tree nil)
 
==> NIL
Создана глобальная переменная tree
 
(setq tree (add-in-tree tree 1))
 
==> (1 NIL NIL)
 
(setq tree (add-in-tree tree 2))
 
==> (1 NIL (2 NIL NIL))
 
(setq tree (add-in-tree tree -2))
 
==> (1 (-2 NIL NIL) (2 NIL NIL))

(defparameter daily-planet '((olsen jimmy 123-76-4535 cub-reporter)
(kent clark 089-52-6787 reporter)
(lane lois 951-26-1438 reporter)
(white perry 355-16-7439 editor)))
 
> (mapcar #'caddr daily-planet)
(|123-76-4535| |089-52-6787| |951-26-1438| |355-16-7439|)

(defun MAKE-SET (l)
    (cond
        ((null l) nil)
        ((null (DIG (cdr l) (car l))) (cons (car l) (MAKE-SET (cdr l))))
        (t (MAKE-SET (cdr l)))))
 
(defun DIG (l x)
    (cond
        ((null l) nil)
        ((equal (car l) x) t)
        (t (DIG (cdr l) x))))
 
(MAKE-SET '(a b c 1 b c d 2 1))
 
==> (a b c d 2 1)

(defun make-set (lst &optional r)
  (cond ((null lst) r)
        ((member (car lst) r) (make-set (cdr lst) r))
        (t (make-set (cdr lst) (cons (car lst) r)))))
 
==> make-set
 
(make-set '(1 2 3 1 2 3 a b c a b c))
 
==> (c b a 3 2 1)
 
(defun make-set (lst)
  (let ((r nil))
    (dolist (i lst r)
      (unless (member i r) (push i r)))))
 
==> make-set
 
(make-set '(1 2 3 1 2 3 a b c a b c))
 
==> (c b a 3 2 1)

(defun setof-h (w &aux result (ht (make-hash-table)))
  (dolist (i w)
    (setf (gethash i ht) 1))
  (maphash #'(lambda (key val) (declare (ignore val)) (push key result)) ht)
  result)
 
> (setof-h '(1 3 a 2 1 b 2 a))
(b a 3 2 1)