day 1 puzzle 2

src/day1/puzzle2.typ

@@ -0,0 +1,36 @@
+#import "/src/utils.typ": *
+
+#let solve(input) = {
+  let lines = input.split("\n")
+  let (l1, l2) = ((), ())
+  let reg = regex("^(\d+)\s+(\d+)$")
+  for line in lines {
+    let digits = line.match(reg)
+    l1.push(digits.captures.first())
+    l2.push(digits.captures.last())
+  }
+
+  let nums = (:)
+
+  for n in l1 {
+    if n not in nums.keys() {
+      nums.insert(n, (0, 0))
+    }
+    nums.at(n).first() += 1
+  }
+
+  for n in l2 {
+    if n in nums.keys() {
+      nums.at(n).last() += 1
+    }
+  }
+
+  let total = nums.pairs().map(((num, (a, b))) => int(num) * a * b).sum()
+  return total
+}
+
+#show-puzzle(
+  1,
+  solve,
+  example: 31
+)