【问题】
Define a procedure that takes three numbers as arguments and returns the sum of the squares of the two larger numbers.
定义一个过程,它以三个数为参数,返回其中较大的两个数的平方和。
【普通版】
(define (sum-square-largest x y z) (cond ((and (> y x) (> z x)) ;; y and z are largest (+ (* y y) (* z z))) ((and (> x y) (> z y)) ;; x and z are largest (+ (* x x) (* z z))) ((and (> x z) (> y z)) ;; x and y are largest (+ (* x x) (* y y)))))
【大神版】
(define (sum-square-largest x y z) (cond ((and (< x y) (< x z)) ;; x is smallest (+ (* y y) (* z z))) (else (sum-square-largest y z x))))
Structure and Interpretation of Computer Programs-Exercise 1.3,布布扣,bubuko.com
Structure and Interpretation of Computer Programs-Exercise 1.3
原文地址:http://blog.csdn.net/jjjcainiao/article/details/35599743