Topic: A recursion way of coding

[Lee Mac]

Another tail-recursive version:

Code - Auto/Visual Lisp: [Select]

1. (defun odd ( l / foo )
2.     (defun foo ( l a )
3.         (cond
4.             (   (null l)
5.                 (reverse a)
6.             )
7.             (   (listp (car l))
8.                 (foo (cdr l) (append (reverse (odd (car l))) a))
9.             )
10.             (   (= 1 (rem (car l) 2))
11.                 (foo (cdr l) (cons (car l) a))
12.             )
13.             (   (foo (cdr l) a))
14.         )
15.     )
16.     (foo l nil)
17. )

Example:

Code - Auto/Visual Lisp: [Select]

1. _$ (odd '(1 2 (3 4 5 6 7) 8 9))
2. (1 3 5 7 9)

[Coder]

Very great works experts 

All codes work very nice , Fantastic .

I was in a hurry today and forgot to mention if it is possible to include the brackets from the sub-list .  :ugly:

Example :

(1 (3 5 7) 9)

Many many thanks , and please bear with me guys .

[Lee Mac]

I was in a hurry today and forgot to mention if it is possible to include the brackets from the sub-list .  :ugly:

Example :

(1 (3 5 7) 9)

My code updated:

Code - Auto/Visual Lisp: [Select]

1. (defun odd ( l )
2.     (vl-remove nil
3.         (mapcar
4.             (function
5.                 (lambda ( x )
6.                     (if (numberp x)
7.                         (if (= 1 (rem x 2)) x)
8.                         (odd x)
9.                     )
10.                 )
11.             )
12.             l
13.         )
14.     )
15. )

Code - Auto/Visual Lisp: [Select]

1. (defun odd ( l )
2.     (if (numberp l)
3.         (if (= 1 (rem l 2)) l)
4.         (if l (vl-remove nil (cons (odd (car l)) (odd (cdr l)))))
5.     )
6. )

Code - Auto/Visual Lisp: [Select]

1. (defun odd ( l / foo )
2.     (defun foo ( l a )
3.         (cond
4.             (   (null l)
5.                 (reverse a)
6.             )
7.             (   (listp (car l))
8.                 (foo (cdr l) (cons (odd (car l)) a))
9.             )
10.             (   (= 1 (rem (car l) 2))
11.                 (foo (cdr l) (cons (car l) a))
12.             )
13.             (   (foo (cdr l) a))
14.         )
15.     )
16.     (foo l nil)
17. )

Code - Auto/Visual Lisp: [Select]

1. _$ (odd '(1 2 (3 4 5 6 7) 8 9))
2. (1 (3 5 7) 9)

[Coder]

A very great work Lee ,
thank you so much for your kind reply and rare generosity .

[Lee Mac]

You're welcome Coder