1 files changed, 47 insertions, 0 deletions
diff --git a/year2021/day24/checker.clj b/year2021/day24/checker.clj
new file mode 100644
index 0000000..4874f62
--- /dev/null
+++ b/year2021/day24/checker.clj
@@ -0,0 +1,47 @@
+(require '[clojure.string :as str])
+
+(defn alu-parse-argument [arg]
+  (if (contains? #{\w \x \y \z} (first arg))
+    (str/join ["@" arg])
+    (read-string arg)))
+
+(defn alu-parse-instruction [[ins arg1 arg2]]
+  (let [arg2-parsed (if (some? arg2) (alu-parse-argument arg2) 0)]
+    (case ins
+      "inp"
+      (str/join ["(reset! " arg1 " (- (int (get input (swap! index inc))) 48))\n"])
+      "add"
+      (str/join ["(swap! " arg1 " +' " arg2-parsed ")\n"])
+      "mul"
+      (str/join ["(swap! " arg1 " *' " arg2-parsed ")\n"])
+      "div"
+      (str/join ["(swap! " arg1 " quot " arg2-parsed ")\n"])
+      "mod"
+      (str/join ["(swap! " arg1 " rem " arg2-parsed ")\n"])
+      "eql"
+      (str/join ["(swap! " arg1 " #(if (= % " arg2-parsed ") 1 0))\n"]))))
+
+(def alu-program-header
+    "(defn alu-program [input]
+     (let [index (atom -1) w (atom 0) x (atom 0) y (atom 0) z (atom 0)]\n")
+
+(defn alu-compile-program [instructions]
+  (let [parsed-ins (mapv alu-parse-instruction instructions)]
+    (eval (read-string
+      (str/join [alu-program-header
+                 (str/join parsed-ins)
+                 "@z))"])))))
+
+(def program (->> (slurp "./in")
+                  str/split-lines
+                  (map #(str/split % #"\s+"))
+                  (alu-compile-program)))
+
+; to split by `inp w`s:
+;                  (partition 18)
+;                  (reverse)
+;                  (mapv alu-compile-program)))
+
+(println "Part 1:" (program "16181111641521"))
+(println "Part 2:" (program "59692994994998"))
+