happy holidays 2025

2025-12-01 11:06:15 -10:00
parent de3c367d1c
commit 4d525dd3a7
5 changed files with 4713 additions and 0 deletions
@@ -0,0 +1,38 @@
+(ns day01
+  (:require input-manager
+            #_[clojure.string :as str]))
+
+(defn parse-line [line]
+  [(.charAt line 0)
+   (parse-long (.substring line 1))])
+
+(def input (->> (input-manager/get-input 2025 01)
+                (map parse-line)))
+
+(def op {\R +, \L -})
+
+(defn normalize [n]
+  (mod n 100))
+
+;; part 1
+(->> input
+     (reductions (fn [acc [dir turn-cnt]]
+                   (normalize ((op dir) acc turn-cnt)))
+                 50)
+     (filter (partial = 0))
+     count)
+
+;; part 2
+(->> input
+     (reduce (fn [[acc dial] [dir turn-cnt]]
+               (let [next-dial ((op dir) dial turn-cnt)]
+                 [(+ acc (cond (> next-dial 99) (int (/ next-dial 100))
+                               (< next-dial 0) (+ (abs (int (/ next-dial 100)))
+                                                  (if (= dial 0)
+                                                    0
+                                                    1))
+                               (= next-dial 0) 1
+                               :else 0))
+                  (normalize next-dial)]))
+             [0 50])
+     first)