repeating-decimal.clj

(ns repeating-decimal)

(defn repeating-decimal [n]
  (loop [rem 1 rems #{} divs [] i 0]
    (let [div (int (/  (* rem 10) n))
          rem (mod  (* rem 10) n)]
      (if (and (not= rem 0) (contains? rems rem))
        [n divs]
        (when (not= rem 0)
          (recur rem (conj rems rem) (conj divs div) (inc i)))))))

(repeating-decimal 7)
(repeating-decimal 11)
(repeating-decimal 12)
(repeating-decimal 97)

(def nums (for [[n qs] (map repeating-decimal (range 1 100001))
                :when n]
            [n qs]))

(def max-num (last (sort-by second nums)))

(-> max-num first)
(-> max-num second count)