Scheme function to reverse a list

Question

For my programming languages class I\'m supposed to write a function in Scheme to reverse a list without using the pre-made reverse function. So far what I got was

Answer 1

The problem with your implementation is that cons isn't receiving a list as its second parameter, so the answer you're building isn't a proper list, remember: a proper list is constructed by consing an element with a list, and the last list is empty.

One possible workaround for this is to use a helper function that builds the answer in an accumulator parameter, consing the elements in reverse - incidentally, this solution is tail recursive:

(define (reverse lst)
  (reverse-helper lst '()))

(define (reverse-helper lst acc)
  (if (null? lst)
      acc
      (reverse-helper (cdr lst) (cons (car lst) acc))))

(reverse '(1 2 3 4 5))
=> '(5 4 3 2 1)