On 7/20/10 9:54 AM, Matthias Felleisen wrote:
Do you mean this? #lang racket (require rackunit) ;; Nat Nat *-> [Listof Nat] ;; which of the (define (same-parity x . xs) (cons x (filter (λ (o) (or (and (even? x) (even? o)) (and (odd? x) (odd? o)))) xs))) (check-equal? (same-parity 1 2 3 4 5 6 7) '(1 3 5 7)) (check-equal? (same-parity 2 3 4 5 6 7) '(2 4 6))
A little more succinct and efficient: (define (same-parity x . xs) (cons x (filter (if (even? x) even? odd?) xs))) David _________________________________________________ For list-related administrative tasks: http://lists.racket-lang.org/listinfo/users
