Project Euler: Problem 1

Posted on by technologeo

Challenge:

If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9. The sum of these multiples is 23.

Find the sum of all the multiples of 3 or 5 below 1000.

Programming Language:

LISP

Solution:

(defun 3n5 (num)
  (defparameter sum 0)
  (loop for x from 1 below num do
       (if (or (eq (mod x 3) 0) (eq (mod x 5) 0))
	   (setq sum (+ sum x))))
  (format t "Sum of all multiples of 3 or 5 below ~a is: ~a~%" num sum))

Overview:

Coming soon…

Published by technologeo