Parity Function

parity_function.scm

; 2.20

(define (same-parity first . remaining)
  (define (iter-list parity-list unprocessed-remaining)
    (if (null? unprocessed-remaining)
        parity-list
        (if (= (remainder first 2) (remainder (car unprocessed-remaining) 2))
            (iter-list (cons(car unprocessed-remaining) parity-list) (cdr unprocessed-remaining))
            (iter-list parity-list (cdr unprocessed-remaining)))
        )
    )
  (iter-list null remaining))

(same-parity 2 1 2 3 4 5) ;----> (4, 2)