aoc 2020 day 9 part 2

aoc2020day9part2.clj

(defn parse-input []
  (->> (slurp "puzzle-inputs/2020/day9")
       (str/split-lines)
       (map #(Long/parseLong %))))
       
(defn reduce-window [part]
  (let [min (apply min part)
      max (apply max part)]
      [(+ min max) (reduce + 0 part)]))

(time (let [invalid 14144619
            input (parse-input)]
        (loop [i 4]
          (let [sums (->> (partition i 1 input)
                          (map reduce-window))
                found? (for [xs sums
                             :when (= invalid (second xs))]
                         (first xs))]
            (if (seq found?)
              (first found?)
              (recur (inc i)))))))