EVENREV: (evenrev lst) should return a new list, formed from the even-numbered e

ID: 3545503 • Letter: E

Question

EVENREV:

(evenrev lst) should return a new list, formed from the even-numbered elements

taken from lst, but in the reverse of their original order. That is,

(evenrev '(a b c d e f g))

should return:

(f d b)

(evenrev (LIST 's 't 'u 'v 'w 'x 'y 'z))

should return:

(z x v t)

I have a function that returns even written but don't know how to make it reverse

(DEFINE (evenrev lst)

(cond (

(null? lst)

'())

(

(null? (cdr lst))

'())

(else

(cons (cadr lst)

(evenrev (cddr lst))))))

(define (evenrev lst)

(cond ((list? lst)

(cond

( (null? lst) '())

( (null? (cdr lst)) '())

(else (append (evenrev (cddr lst)) (list (cadr lst)) ))))

(else '()) ))

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