X-Git-Url: http://git.jkinsey.net/?p=adventofcode2019.git;a=blobdiff_plain;f=src%2Fadventofcode2019%2Fday16.clj;fp=src%2Fadventofcode2019%2Fday16.clj;h=04d6714636da5e79938305e86fead68c91998a86;hp=0000000000000000000000000000000000000000;hb=21ab31d9418c308ae58d73141184be8b42a11ab8;hpb=49dee54b66741b6ad08ef15fb46e15310edbd765

diff --git a/src/adventofcode2019/day16.clj b/src/adventofcode2019/day16.clj
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+++ b/src/adventofcode2019/day16.clj
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+(ns adventofcode2019.day16
+  [:require [adventofcode2019.lib :refer :all]
+   [clojure.string :as str]])
+
+(defn parse-input [input]
+  (map (comp parse-int str) input))
+
+(defn phase [input]
+  (let [pattern (fn [n]
+                  (->> [0 1 0 -1]
+                       (mapcat (partial repeat n))
+                       (cycle)
+                       (rest)))
+        transform (fn [i n]
+                    (->> (map * input (pattern (inc i)))
+                         (reduce +)
+                         (str)
+                         (last)
+                         (str)
+                         (parse-int)))]
+    (map-indexed transform input)))
+
+(defn result-of [input]
+  (as-> (parse-input input) it
+        (iterate phase it)
+        (nth it 100)
+        (take 8 it)
+        (str/join it)))
+
+(defn day16 []
+  (let [[input] (get-list-from-file (input-file))]
+    (part1 (result-of input))
+    #_(part2)))