From 8d43e37df99f280377bed90284d6ac2428334804 Mon Sep 17 00:00:00 2001 From: Clyne Sullivan <clyne@bitgloo.com> Date: Wed, 30 Nov 2022 19:55:31 -0500 Subject: move 2021 days to folder; update README --- year2021/day19/partboth.clj | 98 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 year2021/day19/partboth.clj (limited to 'year2021/day19') diff --git a/year2021/day19/partboth.clj b/year2021/day19/partboth.clj new file mode 100644 index 0000000..48f1a9c --- /dev/null +++ b/year2021/day19/partboth.clj @@ -0,0 +1,98 @@ +(require '[clojure.core.reducers :as r]) +(require 'clojure.string) + +(def orientation-vectors + [[[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]]]) + +(defn build-scanner-reports + "Splits slurped, split-line'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] + (map #(orient (map - %) (get orientation-vectors or-index)) report)) + +(defn scanner-orientations + "Builds list of scanner reports adjusted for all possible orientations." + [report] + (for [or-vec orientation-vectors] + (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] + (loop [potential-links (as-> (scanner-build-potential-links s1 s2) $ + (for [i (range 0 (count $))] [i (nth $ i)]) + (into [] $))] + (when-let [[orientation link] (first potential-links)] + (if-let [match (first (drop-while #(< (val %) 12) (frequencies (reduce concat link))))] + [orientation (key match)] + (recur (rest potential-links)))))) + +(defn scanner-merge + "Merges the report of linked scanner s2 into scanner s1." + [s1 s2 s2-or s2-coord] + (vec (into (set s1) (map #(point-add s2-coord (map - %)) (scanner-orientation s2 s2-or))))) + +(let [[beacon-count scanner-coords] + (loop [new-reps (->> (slurp "./in") clojure.string/split-lines build-scanner-reports) + sc-coords '([0 0 0]) + next-reps (rest new-reps)] + (if-let [next-rep (first next-reps)] + (if-let [[found-or found-coord] (scanner-find-connection (first new-reps) next-rep)] + (let [new-base (scanner-merge (first new-reps) next-rep found-or found-coord) + newest-reps (->> (assoc new-reps 0 new-base) (filterv (partial not= next-rep)))] + (println "found" found-coord) + (recur newest-reps (conj sc-coords found-coord) (rest newest-reps))) + (recur new-reps sc-coords (rest next-reps))) + [(count (first new-reps)) sc-coords]))] + (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))))))) + -- cgit v1.2.3