A_advent-of-code-2017.clj

;; Utility functions:
;; Space separted number values:
(defn ssn [s] (mapv #(Long/parseLong %) (str/split s #"\s+")))

day6.clj

(def day5 "2\t8\t8\t5\t4\t2\t3\t1\t5\t5\t1\t2\t15\t13\t5\t14")
(def day5-ex "0 2 7 0")

(defn max-idx [xs]
  (count (take-while #(not= % (apply max xs)) xs)))

(defn spread-idx
  [xs idx]
  (let [v (nth xs idx)]
    (->> (concat (repeat idx 0) [(- v)] (repeat v 1))
         (partition (count xs) (count xs) (repeat 0))
         (apply mapv + xs))))

(defn solve-day-5
  [xs]
  (loop [seen {xs 0}, xs xs, i 1]
    (let [xs* (spread-idx xs (max-idx xs))]
      (if (seen xs*)
        {:part1 (count seen) :part2 (- (count seen) (seen xs*))}
        (recur (assoc seen xs* i) xs* (inc i))))))
#_(solve-day-5 (ssn day5))
#_(solve-day-5 (ssn day5-ex))

day8.clj

(let [max' (fn [xs] (apply max xs))
      regs (reductions
             (fn [m [reg op num _ c-reg cmp c-num]]
               (let [num (Long/parseLong num)
                     c-num (Long/parseLong c-num)
                     != not=
                     if-op (resolve (read-string cmp))]
                 (if (if-op (get m c-reg 0) c-num)
                   (update m reg (fnil (get {"inc" + "dec" -} op) 0) num)
                   m)))
             {} (mapv #(str/split % #"\s+") (line-seq (io/reader "day8.txt"))))]
  {:part1 (max' (vals (last regs)))
   :part2 (max' (mapv max' (keep vals regs)))})