(define (next n)
(if (= n 2)
3
(+ n 2)))
(define (find-divisor n test-divisor)
(cond ((> (square test-divisor) n) n)
((divides? n test-divisor) test-divisor)
(else (find-divisor n (next test-divisor)))))
(define (smallest-divisor n)
(find-divisor n 2))
(define (divides? a b)
(= (remainder a b) 0))
(define (prime? n)
(= n (smallest-divisor n)))
(define (square x)
(* x x))
(smallest-divisor 177)
转载于:https://www.cnblogs.com/R4mble/p/7892524.html
相关资源：SICP 习题答案
