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/day11/part2.clj | 42 ++++++++++++++++++++++++++++++++++++++++++
1 file changed, 42 insertions(+)
create mode 100644 year2021/day11/part2.clj
(limited to 'year2021/day11/part2.clj')
diff --git a/year2021/day11/part2.clj b/year2021/day11/part2.clj
new file mode 100644
index 0000000..4c4663c
--- /dev/null
+++ b/year2021/day11/part2.clj
@@ -0,0 +1,42 @@
+(defn get-adj [in y x]
+ (filter
+ #(some? (get-in in %))
+ [[(dec y) (dec x)] [(dec y) x] [(dec y) (inc x)]
+ [y (dec x)] [y (inc x)]
+ [(inc y) (dec x)] [(inc y) x] [(inc y) (inc x)]]
+ ))
+
+(defn apply-incs [in] (mapv (partial mapv inc) in))
+
+(defn next-step [indata]
+ (loop [in (apply-incs (indata :grid)) bl (indata :blinks) y 0 x 0]
+ (cond
+ (> (get-in in [y x]) 9)
+ (do
+ (recur
+ (-> (reduce
+ (fn [i n] (update-in i n #(cond-> % (pos? %) inc)))
+ in
+ (get-adj in y x))
+ (update-in [y x] #(do % 0)))
+ (inc bl)
+ 0 0))
+ (< x (dec (count (first in))))
+ (recur in bl y (inc x))
+ (< y (dec (count in)))
+ (recur in bl (inc y) 0)
+ :else
+ {:grid in :blinks bl}
+ )
+ )
+ )
+
+(->> (slurp "./in")
+ (clojure.string/split-lines)
+ (map (partial map #(- (int %) 48)))
+ (assoc {} :blinks 0 :grid)
+ (iterate next-step)
+ (take-while #(pos? (apply + (flatten (% :grid)))))
+ (count)
+ (println))
+
--
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