SICP 2.17 2.18 2.19

为什么80%的码农都做不了架构师？>>>   

2.17

(define (last-pair lst)
  (if (null? (cdr lst))
      lst
      (last-pair (cdr lst))))

2.18

(define (my-reverse lst)
  (define (x-reverse l r)
    (if (null? l)
        r
        (x-reverse (cdr l) (cons (car l) r))))
  (x-reverse lst '()))

2.19

(define except-first-denomination cdr)
(define first-denomination car)
(define no-more? null?)

 

转载于:https://my.oschina.net/guzhou/blog/724469