sicp习题试解 (2.18)

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;

; Structure and Interpretation of Computer Programs

; (trial answer to excercises)

;

; 计算机程序的构造和解释(习题试解)

;

; created: code17 07/14/05

; modified:

; (保持内容完整不变前提下，可以任意转载)

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;; SICP No.2.18

(define (reverse items)

(define (reverse-iter i k)

(if (null? i) k (reverse-iter (cdr i) (cons (car i) k))))

(reverse-iter items ()))

;; Test-it:

;; Welcome to MzScheme version 209, Copyright (c) 2004 PLT Scheme, Inc.

;; > (reverse ())

;; ()

;; > (reverse (list 1))

;; (1)

;; > (reverse (list 1 4 9 16 25))

;; (25 16 9 4 1)