24/4 in clj

clojure/y2024/d04.bb

@@ -0,0 +1,32 @@
+#!/usr/bin/env bb
+
+(ns y2024.d04
+  (:require [babashka.cli :as cli]
+            [clojure.string :as str]))
+
+
+(def cli-options {:input {:default "../../inputs/2024/04.input" :type :string}})
+
+(def opts (cli/parse-opts *command-line-args* {:spec cli-options}))
+
+(def input
+  (->> (slurp (get opts :input))))
+
+(defn part1 [data]
+  (let [w (str/index-of data "\n")
+        patterns
+        (flatten (for [i [0 w (inc w) (dec w)]]
+                   [(re-pattern (str "(?s)(?=X.{" i "}M.{" i "}A.{" i "}S)"))
+                    (re-pattern (str "(?s)(?=S.{" i "}A.{" i "}M.{" i "}X)"))]))]
+    (reduce + (map #(count (re-seq % data)) patterns))))
+
+
+(defn part2 [data]
+  (let [w (dec (str/index-of data "\n"))
+        patterns
+        (for [[tl tr bl br] ["MMSS" "MSMS" "SSMM" "SMSM"]]
+          (re-pattern (str "(?s)(?=" tl "." tr ".{" w "}A.{" w "}" bl "." br")")))]
+    (reduce + (map #(count (re-seq % data)) patterns))))
+
+(prn {:part1 (part1 input)
+      :part2 (part2 input)})