August 19, 2024
P07 - Flatten a nested list structure
Transform a list, possibly holding lists as elements into a `flat' list by replacing each list with its elements (recursively).
Example:* (my-flatten '(a (b (c d) e)))(A B C D E)
Hint: Use the predefined functions list and append.
lisp
;;; Recebe uma lista e retorna uma lista que, no lugar dos ;;;
;;; elementos que são sub-listas, possui os elementos dessas ;;;
;;; sub-listas, recursivamente. ;;;
(defun flatten (orig-list)
(if (eql orig-list nil)
nil
(let ((elem (car orig-list)) (resto-list (cdr orig-list)))
(if (listp elem)
(append (flatten elem) (flatten resto-list))
(append (cons elem nil) (flatten resto-list))))))
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