Question

I’m trying to learn scheme via SICP. Exercise 1.3 reads as follow: Define a procedure that takes three numbers as arguments and returns the sum of the squares of the two larger numbers. Please comment on how I can improve my solution.

(define (big x y)     (if (> x y) x y))  (define (p a b c)     (cond ((> a b) (+ (square a) (square (big b c))))           (else (+ (square b) (square (big a c)))))) 

Answer 1

Looks ok to me, is there anything specific you want to improve on?

You could do something like:

(define (max2 . l)   (lambda ()     (let ((a (apply max l)))       (values a (apply max (remv a l))))))  (define (q a b c)   (call-with-values (max2 a b c)     (lambda (a b)       (+ (* a a) (* b b)))))  (define (skip-min . l)   (lambda ()     (apply values (remv (apply min l) l))))  (define (p a b c)   (call-with-values (skip-min a b c)     (lambda (a b)       (+ (* a a) (* b b))))) 

And this (proc p) can be easily converted to handle any number of arguments.