day 11 puzzle 1

progress.yaml

@@ -17,4 +17,6 @@
 9:
   stars: 2
 10:
-  stars: 2
+  stars: 2
+11:
+  stars: 1

res/examples/day11.txt

@@ -0,0 +1 @@
+125 17

src/day11/puzzle1.typ

@@ -0,0 +1,40 @@
+#import "/src/utils.typ": *
+
+#let process(rock) = {
+  if rock == 0 {
+    return (1,)
+  }
+  let rock-str = str(rock)
+  if calc.rem(rock-str.len(), 2) == 0 {
+    let hl = calc.div-euclid(rock-str.len(), 2)
+    return (
+      int(rock-str.slice(0, hl)),
+      int(rock-str.slice(hl))
+    )
+  }
+  return (rock * 2024,)
+}
+
+#let blink(rocks) = {
+  let new-rocks = ()
+
+  for rock in rocks {
+    new-rocks += process(rock)
+  }
+
+  return new-rocks
+}
+
+#let solve(input) = {
+  let rocks = input.split(" ").map(int)
+  for _ in range(25) {
+    rocks = blink(rocks)
+  }
+  return rocks.len()
+}
+
+#show-puzzle(
+  11, 1,
+  solve,
+  example: 55312
+)