24/2 in clj

clojure/y2024/d02.bb

@@ -0,0 +1,43 @@
+#!/usr/bin/env bb
+
+(ns y2024.d02
+  (:require [babashka.cli :as cli]
+            [clojure.string :as str]))
+
+
+(def cli-options {:input {:default "../../inputs/2024/02.input" :type :string}})
+
+(def opts (cli/parse-opts *command-line-args* {:spec cli-options}))
+
+(def input
+  (->> (slurp (get opts :input))
+       (str/split-lines)
+       (map #(str/split % #" "))
+       (map #(map parse-long %))
+       (map #(into [] %))))
+
+(defn one-way-safe? [xs]
+  (let [pairs (partition 2 1 xs)]
+    (every? (fn [[lhs rhs]]
+              (< lhs rhs (+ lhs 4)))
+            pairs)))
+
+(defn safe? [xs]
+  (or (one-way-safe? xs)
+      (one-way-safe? (reverse xs))))
+
+(defn part1 [data]
+  (count (filter safe? data)))
+
+(defn lenient-safe? [xs]
+  (or (safe? xs)
+      (let [n (count xs)]
+        (->> (range n)
+             (map #(into [] (concat (take % xs) (drop (inc %) xs))))
+             (some safe?)))))
+
+(defn part2 [data]
+  (count (filter lenient-safe? data)))
+
+(prn {:part1 (part1 input)
+      :part2 (part2 input)})