do day 22

2024/src/day22.clj

@@ -0,0 +1,52 @@
+(ns day22
+  (:require input-manager))
+
+(def input (->> (input-manager/get-input 2024 22)
+                (map parse-long)))
+
+(def prune-const 16777216)
+(defn prune [x] (mod x prune-const))
+(defn mix [secret v] (bit-xor secret v))
+
+(defn next-step [secret]
+  (let [a (prune (mix secret (* secret 64)))
+        b (prune (mix a (int (/ a 32))))
+        c (prune (mix b (* b 2048)))]
+    c))
+
+(defn get-nums
+  ([n] (get-nums n 0))
+  ([n i] (lazy-seq (cons n (get-nums (next-step n) (inc i))))))
+
+(def solutions (->> input
+                    (map get-nums)
+                    (mapv (comp (partial into [])
+                                (partial take 2001)))))
+
+;; part 1 sol
+(->> solutions
+     (map last)
+     (apply +))
+
+;; part 2 sol
+(->> (map (partial map #(mod % 10)) solutions)
+     (map #(map (fn [& prices]
+                  (let [price-diff-list (map - (rest prices) prices)
+                        sell-price (last prices)]
+                    [price-diff-list sell-price]))
+                % (rest %) (drop 2 %) (drop 3 %) (drop 4 %)))
+     (reduce (fn [acc buyer]
+               (->> (reduce (fn [[visited acc2] [price-diff-list price]]
+                              (if (visited price-diff-list)
+                                [visited acc2]
+                                [(conj visited
+                                       price-diff-list)
+                                 (update acc2
+                                         price-diff-list
+                                         #(+ (or % 0) price))]))
+                            [#{} acc]
+                            buyer)
+                    second))
+             {})
+     vals
+     (apply max))