day 3 puzzle 1

src/day3/puzzle1.typ

@@ -0,0 +1,16 @@
+#import "/src/utils.typ": *
+
+#let solve(input) = {
+  let matches = input.matches(regex("mul\((\d{1,3}),(\d{1,3})\)"))
+  let total = matches.map(m => {
+    m.captures.map(int)
+              .product()
+  }).sum()
+  return total
+}
+
+#show-puzzle(
+  3, 1,
+  solve,
+  example: 161
+)