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Diffstat (limited to 'day19/partboth.clj')
| -rw-r--r-- | day19/partboth.clj | 158 |
1 files changed, 158 insertions, 0 deletions
diff --git a/day19/partboth.clj b/day19/partboth.clj new file mode 100644 index 0000000..4de2c42 --- /dev/null +++ b/day19/partboth.clj @@ -0,0 +1,158 @@ +(require '[clojure.core.reducers :as r]) +(require 'clojure.string) + +(defn build-scanner-reports + "Splits slurped, split-lines'd input by scanner." + [input-lines] + (loop [scanners [] rem-input input-lines] + (if (empty? rem-input) + scanners + (let [[this nxt] (split-with (comp not empty?) rem-input)] + (recur + (->> (rest this) + (map #(read-string (clojure.string/join ["[" % "]"]))) + (conj scanners)) + (rest nxt)))))) + +(defn point-add [[a b c] [d e f]] [(+ a d) (+ b e) (+ c f)]) + +(defn orient [[x y z] [[a b c] [d e f] [g h i]]] + [(+ (* x a) (* y d) (* z g)) (+ (* x b) (* y e) (* z h)) (+ (* x c) (* y f) (* z i))]) + +(defn scanner-orientation [report or-index] + (let [or-vec [[[1 0 0] [0 1 0] [0 0 1]] + [[1 0 0] [0 0 -1] [0 1 0]] + [[1 0 0] [0 -1 0] [0 0 -1]] + [[1 0 0] [0 0 1] [0 -1 0]] + [[-1 0 0] [0 -1 0] [0 0 1]] + [[-1 0 0] [0 0 -1] [0 -1 0]] + [[-1 0 0] [0 1 0] [0 0 -1]] + [[-1 0 0] [0 0 1] [0 1 0]] + [[0 0 -1] [1 0 0] [0 -1 0]] + [[0 1 0] [1 0 0] [0 0 -1]] + [[0 0 1] [1 0 0] [0 1 0]] + [[0 -1 0] [1 0 0] [0 0 1]] + [[0 0 1] [-1 0 0] [0 -1 0]] + [[0 1 0] [-1 0 0] [0 0 1]] + [[0 0 -1] [-1 0 0] [0 1 0]] + [[0 -1 0] [-1 0 0] [0 0 -1]] + [[0 -1 0] [0 0 -1] [1 0 0]] + [[0 0 1] [0 -1 0] [1 0 0]] + [[0 1 0] [0 0 1] [1 0 0]] + [[0 0 -1] [0 1 0] [1 0 0]] + [[0 0 1] [0 1 0] [-1 0 0]] + [[0 -1 0] [0 0 1] [-1 0 0]] + [[0 0 -1] [0 -1 0] [-1 0 0]] + [[0 1 0] [0 0 -1] [-1 0 0]]] + chosen (get or-vec or-index)] + (map #(orient (map - %) chosen) report))) + +(defn scanner-orientations + "Builds list of scanner reports adjusted for all possible orientations." + [report] + (for [or-vec [[[1 0 0] [0 1 0] [0 0 1]] + [[1 0 0] [0 0 -1] [0 1 0]] + [[1 0 0] [0 -1 0] [0 0 -1]] + [[1 0 0] [0 0 1] [0 -1 0]] + [[-1 0 0] [0 -1 0] [0 0 1]] + [[-1 0 0] [0 0 -1] [0 -1 0]] + [[-1 0 0] [0 1 0] [0 0 -1]] + [[-1 0 0] [0 0 1] [0 1 0]] + [[0 0 -1] [1 0 0] [0 -1 0]] + [[0 1 0] [1 0 0] [0 0 -1]] + [[0 0 1] [1 0 0] [0 1 0]] + [[0 -1 0] [1 0 0] [0 0 1]] + [[0 0 1] [-1 0 0] [0 -1 0]] + [[0 1 0] [-1 0 0] [0 0 1]] + [[0 0 -1] [-1 0 0] [0 1 0]] + [[0 -1 0] [-1 0 0] [0 0 -1]] + [[0 -1 0] [0 0 -1] [1 0 0]] + [[0 0 1] [0 -1 0] [1 0 0]] + [[0 1 0] [0 0 1] [1 0 0]] + [[0 0 -1] [0 1 0] [1 0 0]] + [[0 0 1] [0 1 0] [-1 0 0]] + [[0 -1 0] [0 0 1] [-1 0 0]] + [[0 0 -1] [0 -1 0] [-1 0 0]] + [[0 1 0] [0 0 -1] [-1 0 0]]]] + (map #(orient (map - %) or-vec) report))) + +(defn scanner-build-potential-links + "Builds a list for each s2 orientation that contains lists of each s1 point + added to the corresponding s2 point." + [s1 s2] + (for [s2-or (scanner-orientations s2)] + (for [i (range 0 (count s1))] + (for [j (range 0 (count s2-or))] + (point-add (nth s1 i) (nth s2-or j)))))) + +(defn scanner-find-connection + "Attempt to determine if s1 and s2 are linked through common beacons." + [s1 s2] + (let [potential-links (as-> (scanner-build-potential-links s1 s2) $ + (for [i (range 0 (count $))] [i (nth $ i)]))] + (filter some? + (map + (fn [[orientation link]] + (let [distinct-points (into [] (distinct (reduce concat link))) + link-results + (into '() + (r/fold (quot (count distinct-points) 16) r/cat + (fn [pcoll point] + (if-not (empty? pcoll) + pcoll + (let [occurrance-count (reduce + #(cond-> %1 + (not (empty? (filter (partial = point) %2))) + inc) + 1 link)] + (cond-> pcoll (> occurrance-count 11) (r/append! point))))) + distinct-points))] + (when (not (empty? link-results)) + [orientation (first link-results)]))) + (into [] potential-links))))) + +(defn scanner-merge + "Merges the report of linked scanner s2 into scanner s1." + [s1 s2 s2-or s2-coord] + (let [s2-ored (scanner-orientation s2 s2-or)] + (distinct (concat s1 (map #(point-add s2-coord (map - %)) s2-ored))))) + +(def reports (->> (slurp "./in") + (clojure.string/split-lines) + (build-scanner-reports) + (vec))) + +(let [[beacon-count scanner-coords] + (loop [new-reps reports sc-coords '([0 0 0]) i (range 1 (count reports))] + (println "Trying" (first i) (map count new-reps)) + (if (nil? (first i)) + ; reached end (uh oh?) + [(count new-reps) sc-coords] + ; scan for links to report i + (let [found (scanner-find-connection (first new-reps) + (get new-reps (first i)))] + (if (empty? found) + ; no match, move to next i + (recur new-reps sc-coords (rest i)) + (do (println " Found" found) + (recur + (-> new-reps + ; replace index zero with merged report + (assoc 0 (scanner-merge (first new-reps) + (get new-reps (first i)) + (first (first found)) + (second (first found)))) + ; remove report we pulled from + (#(concat (subvec % 0 (first i)) + (subvec % (inc (first i))))) + ; back to vector + (vec)) + (conj sc-coords (second (first found))) + ; begin new scan + (range 1 (count new-reps))))))))] + (println "Part 1:" beacon-count) + (println "Part 2:" + (apply max + (for [p1 scanner-coords p2 scanner-coords :when (not= p1 p2)] + (apply + (map #(Math/abs %) (point-add (map - p1) p2))))))) + |