day 3

src/day3.clj

@@ -0,0 +1,35 @@
+(ns day3)
+
+(def input (slurp "inputs/day3"))
+
+(defn mul [instr]
+  (->>
+   instr
+   (re-seq #"\d+")
+   (map parse-long)
+   (apply *)))
+
+(->> input
+     (re-seq #"mul\(\d+,\d+\)")
+     (map mul)
+     (reduce +)
+     (println "result:"))
+
+
+(defn run2 [instructions]
+  (loop
+      [instructions
+       (re-seq #"(don't\(\))|(do\(\))|mul\(\d+,\d+\)" instructions)
+       do true
+       result 0]
+    (if (empty? instructions)
+      result
+      (let [instr (first (first instructions))]
+        (case instr
+          "do()" (recur (rest instructions) true result)
+          "don't()" (recur (rest instructions) false result)
+          (recur (rest instructions)
+                 do
+                 (if do (+ result (mul instr)) result)))))))
+
+(println "result (part 2):" (run2 input))