sicp习题试解 (2.36)

; ======================================================================

;

; 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 08/19/05

; modified:

; (保持内容完整不变前提下，可以任意转载)

; ======================================================================

;; SICP No.2.36

(define (accumulate-n op init seqs)

(if (null? (car seqs))

()

(cons (accumulate op init (map car seqs))

(accumulate-n op init (map cdr seqs)))))

;; Test-it:

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

;; > (accumulate-n + 0 (list (list 1 2 3)

;; (list 4 5 6)

;; (list 7 8 9)

;; (list 10 11 12)))

;; (22 26 30)