day19: wip part 1

day19/part1.clj

@@ -0,0 +1,72 @@
+(require '[clojure.core.reducers :as r])
+(require 'clojure.string)
+
+(defn build-scanner-reports [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 all-orientations [[x y z]]
+  (map (fn [[i j k]] [(* x i) (* y j) (* z k)])
+       '([1 1 1] [-1 1 1] [1 -1 1] [-1 -1 1] [1 1 -1] [-1 1 -1] [1 -1 -1] [-1 -1 -1])))
+
+(defn group-orientations [lst]
+  (for [i (range 0 8)] (map #(nth % i) lst)))
+
+(defn scanner-orientations [scanner]
+  (group-orientations (map all-orientations scanner)))
+
+(defn add-coordinate [[a b c] [d e f]] [(+ a d) (+ b e) (+ c f)])
+
+(defn add-coordinate-lists [l1 l2]
+  (for [i (range 0 (count l1))]
+    (for [j (range 0 (count l2))]
+      (add-coordinate (nth l1 i) (nth l2 j)))))
+
+(defn compare-scanners [s1 s2]
+  (let [o1 [s1];(scanner-orientations s1)
+        o2 (scanner-orientations s2)]
+    (for [o o1 p o2]
+      (add-coordinate-lists o p))))
+
+(defn check-beacon-coord [scanner coord index]
+  (not (empty? (filter #(= coord %) (map #(nth % index) scanner)))))
+
+(defn beacon-coord-match? [req coord compared-scanners]
+  (let [cnt (count (first (first compared-scanners)))]
+    (< (dec req)
+       (reduce
+         (fn [tot n]
+           (cond-> tot
+             (and (< tot req)
+                  (reduce
+                    #(or %1 %2)
+                    (map #(check-beacon-coord % coord n) compared-scanners)))
+             inc))
+         0
+         (range 0 cnt)))))
+
+(->> (slurp "./in")
+     (clojure.string/split-lines)
+     (build-scanner-reports)
+     ((fn [scanners]
+       (for [s1i  (range 0 (count scanners))
+             s2   (drop (inc s1i) scanners)
+             :let [res (compare-scanners (nth scanners s1i) s2)]]
+         (let [cnt (count (first (first res)))]
+           (into '()
+             (r/fold
+               r/cat
+               (fn [final c]
+                 (cond-> final
+                         (beacon-coord-match? 4 c res)
+                         (r/append! c)))
+               (into [] (distinct (nth (iterate (partial reduce concat) res) 2)))))))))
+     (println))
+