diff --git a/partboth.clj b/partboth.clj new file mode 100644 index 0000000..4e460ca --- /dev/null +++ b/partboth.clj @@ -0,0 +1,44 @@ +(require '[clojure.string :as str]) + +(defn pad-input-map [in-map pad-val] + (let [pad-row (repeat (+ 4 (count (first in-map))) pad-val) + pad-side (repeat 2 pad-val)] + (mapv vec + (concat + [pad-row pad-row] + (mapv #(concat pad-side % pad-side) in-map) + [pad-row pad-row])))) + +(defn get-number [in-map y x] + (concat (subvec (get in-map (dec y)) (dec x) (+ 2 x)) + (subvec (get in-map y) (dec x) (+ 2 x)) + (subvec (get in-map (inc y)) (dec x) (+ 2 x)))) + +(defn get-new-pixel [enhance-algo in-map y x] + (->> (get-number in-map y x) + str/join + (#(Integer/parseInt % 2)) + (get enhance-algo) + {\. 0 \# 1})) + +(defn build-output-number-map [enhance-algo in-map] + (let [pad-val (if (= \# (first enhance-algo)) (first (first in-map)) 0) + padded-in-map (pad-input-map in-map pad-val)] + (for [y (range 1 (dec (count padded-in-map)))] + (for [x (range 1 (dec (count (first padded-in-map))))] + (get-new-pixel enhance-algo padded-in-map y x) + )))) + +(defn count-lit-pixels [in-map] + ((frequencies (flatten in-map)) 1)) + +(let [[enhance-algo in-map] + (->> (slurp "./in") + str/split-lines + ((juxt + first + (comp (partial mapv #(mapv {\. 0 \# 1} %)) + (partial drop 2))))) + image-output (iterate (partial build-output-number-map enhance-algo) in-map)] + (println (count-lit-pixels (nth image-output 50)))) +