euler001

euler.clj

(ns euler001.euler)

(defn- zerorem?
  [numer denom]
  (= 0 (rem numer denom)))

(defn divis?
  [a]
  (or 
    (zerorem? a 3)
    (zerorem? a 5)))

(defn multiplesum
  [limit]
  (reduce + (filter divis? (range 1 limit))))

euler_test.clj

(ns euler001.euler-test
  (:use midje.sweet
        euler001.euler))

(fact "multiplesum of 2 is 0"
  (multiplesum 2) => 0)

(fact "multiplesum of 4 is 3"
  (multiplesum 4) => 3)

(fact "divis? checks if arg is divisable by 3 or 5"
  (divis? 2) => false
  (divis? 3) => true
  (divis? 4) => false
  (divis? 5) => true
  (divis? 6) => true
  (divis? 7) => false)

(fact "10 => 23"
  (multiplesum 10) => 23)