list - 如何在方案中编写程序来查找数字列表的因子

Question

这是单个整数的代码，它如何扩展到函数列表？

(define (factors n)
      (define (*factors d)
        (cond ((> d n) (list))
              ((= (modulo n d) 0) (cons d (*factors (+ d 1))))
              (else (*factors (+ d 1)))))
      (*factors 1))
    
    (display (factors 1111111))
    (newline)

Answer 1

您可以使用for-each迭代列表。

(define (factors n)
  (define (*factors d)
    (cond ((> d n) (list))
          ((= (modulo n d) 0) (cons d (*factors (+ d 1))))
          (else (*factors (+ d 1)))))
  (*factors 1))

(define arbitarily-large-input (list 10 11 12))

(for-each (lambda (x)
            (display x)
            (newline))
          (map factors arbitarily-large-input))