diff options
Diffstat (limited to 'day15.clj')
| -rw-r--r-- | day15.clj | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/day15.clj b/day15.clj new file mode 100644 index 0000000..e7155cd --- /dev/null +++ b/day15.clj @@ -0,0 +1,67 @@ +(ns org.vuxu.aoc2021.day15 + (:require [clojure.string :as str])) + +(defn parse-digit [char] + (Character/digit char 10)) + +(def data + (->> (slurp "day15") + (str/split-lines) + (mapv (partial mapv parse-digit)))) + +(defn put-in! [array [x y] v] + (assoc! (get array x) y v)) + +(defn find-path [m] + (let [d (mapv transient (map (partial mapv (constantly 0)) m)) + l (count m)] + (put-in! d [0 0] (get-in m [0 0])) + (loop [q (conj clojure.lang.PersistentQueue/EMPTY [0 1] [1 0])] + (if (empty? q) + (- (get-in d [(dec l) (dec l)]) + (get-in d [0 0])) + (let [[x y] (peek q) + upper (if (and (> x 0) (not= 0 (get-in d [(dec x) y]))) + (get-in d [(dec x) y]) + ##Inf) + bottom (if (and (< x (dec l)) (not= 0 (get-in d [(inc x) y]))) + (get-in d [(inc x) y]) + ##Inf) + left (if (and (> y 0) (not= 0 (get-in d [x (dec y)]))) + (get-in d [x (dec y)]) + ##Inf) + right (if (and (< y (dec l)) (not= 0 (get-in d [x (inc y)]))) + (get-in d [x (inc y)]) + ##Inf) + minpath (+ (get-in m [x y]) (min upper bottom left right)) + ] + (if (or (zero? (get-in d [x y])) + (> (get-in d [x y]) minpath)) + (do + (put-in! d [x y] minpath) + (recur (cond-> (pop q) + (> x 0) (conj [(dec x) y]) + (< x (dec l)) (conj [(inc x) y]) + (> y 0) (conj [x (dec y)]) + (< y (dec l)) (conj [x (inc y)])))) + (recur (pop q)))))))) + + +(def part1 + (find-path data)) + +(def data2 + (let [rows (count data) + cols (count (first data))] + (vec + (for [i (range (* 5 (count data)))] + (vec (for [j (range (* 5 (count (first data))))] + (let [qi (quot i rows) + qj (quot j cols)] + (-> (get-in data [(rem i rows) (rem j cols)]) + dec (+ qi qj) (mod 9) inc)))) + )))) + +(def part2 + (find-path data2) +;; => 2966 |