Advent of Code 2017: Day 01

day_01.clj

(def input (->> "1122"
                (map #(Integer/parseInt (str %)))
                (into [])))

(defn captcha [coll offset]
  (transduce (comp (filter #(apply = %))
                   (map first))
             +
             (mapv vector coll (->> (cycle coll)
                                    (drop offset)
                                    (take (count coll))))))

;; part 1
(captcha input 1)

;; part 2
(captcha input (/ (count input) 2))