| 1 | (ns adventofcode2019.day18 |
| 2 | [:require [adventofcode2019.lib :refer :all] |
| 3 | [adventofcode2019.intcode :as i] |
| 4 | [clojure.string :as str] |
| 5 | [clojure.set :as set] |
| 6 | [clojure.core.match :refer [match]] |
| 7 | [clojure.math.combinatorics :as combo]]) |
| 8 | |
| 9 | (defn build-world [input] |
| 10 | (let [point-encode (->> input |
| 11 | (map-indexed |
| 12 | (fn [y xs] |
| 13 | (map-indexed |
| 14 | (fn [x c] |
| 15 | [c [x y]]) xs))) |
| 16 | (apply concat)) |
| 17 | passages (->> point-encode |
| 18 | (filter #(= \. (first %))) |
| 19 | (map second) |
| 20 | (set)) |
| 21 | interesting (->> point-encode |
| 22 | (filter #(and (not= \. (first %)) |
| 23 | (not= \# (first %)))) |
| 24 | (into {})) |
| 25 | dkeys (select-keys interesting (filter #(Character/isLowerCase %) |
| 26 | (keys interesting))) |
| 27 | doors (select-keys interesting (filter #(Character/isUpperCase %) |
| 28 | (keys interesting))) |
| 29 | player (interesting \@)] |
| 30 | {:p player |
| 31 | :t (apply conj passages player (vals dkeys)) |
| 32 | :k dkeys |
| 33 | :d doors})) |
| 34 | |
| 35 | (defn path-between [trav point-a point-b] |
| 36 | (let [succ (fn [[x y]] |
| 37 | (filter trav |
| 38 | [[(inc x) y] [(dec x) y] |
| 39 | [x (inc y)] [x (dec y)]])) |
| 40 | cost (fn [cs pt] (inc cs)) |
| 41 | heur (partial manhattan-distance point-b) |
| 42 | des? (fn [pt] (= pt point-b))] |
| 43 | (second (a-star succ cost heur point-a des?)))) |
| 44 | |
| 45 | (defn accessible [{player :p dkeys :k trav :t}] |
| 46 | (->> dkeys |
| 47 | (mmap (partial path-between trav player)) |
| 48 | (remove #(= ##Inf (second %))) |
| 49 | (into {}))) |
| 50 | |
| 51 | #_(let [goto-nearest (fn [[p d k]] |
| 52 | (let [l (apply (partial min-key (partial manhattan-distance p)) k)] |
| 53 | [l (+ d (manhattan-distance p l)) (remove #{l} k)]))] |
| 54 | (as-> [p 0 (vals k)] it |
| 55 | (iterate goto-nearest it) |
| 56 | (nth it (dec (count k))) |
| 57 | (second it))) |
| 58 | (defn acquire-all-keys [world] |
| 59 | (let [successor-world (fn [wo [kc ds]] |
| 60 | (let [kp (get-in wo [:k kc]) |
| 61 | dc (Character/toUpperCase kc) |
| 62 | dp (get-in wo [:d dc])] |
| 63 | (-> wo |
| 64 | (assoc :p kp) |
| 65 | (assoc :$ ds) |
| 66 | (update :t conj dp) |
| 67 | (update-in [:k] dissoc kc) |
| 68 | (update-in [:l] conj kc)))) |
| 69 | succ (fn [wo] (map (partial successor-world wo) (accessible wo))) |
| 70 | heur (fn [{:keys [p k]}] |
| 71 | (if (empty? k) 0 |
| 72 | (reduce max (map (partial manhattan-distance p) (vals k))))) |
| 73 | cost (fn [cs pt] (+ cs (pt :$))) |
| 74 | des? (fn [pt] (empty? (pt :k)))] |
| 75 | (second (a-star succ cost heur (assoc world :l []) des?)))) |
| 76 | |
| 77 | (defn day18 [] |
| 78 | (let [input (get-list-from-file (input-file)) |
| 79 | world (build-world input)] |
| 80 | (part1 (acquire-all-keys world)) |
| 81 | #_(part2))) |