day 2 both parts

src/advent_2025.gleam

···
 import day1
+import day2
 import gleam/io
 
 pub fn main() {
   day1.day1main()
+  day2.day2main()
 }

src/day1.gleam

···
 import gleam/int
+import gleam/io
 import gleam/list
 import gleam/string
 import herbie
···
     |> string.split("\n")
 
   let moves = list.map(file, signed)
-  list.fold(moves, #(50, 0), make_move)
+  list.fold(moves, #(50, 0), part1move)
   |> echo
+  list.fold(moves, #(50, 0), part2move)
+  |> echo
+  // nonsense()
 }
 
-fn crosses_zero(starting: Int, move: Int) -> Int {
-  todo
-}
+// fn nonsense() {
+//   echo -123 / 100
+//   echo -123 % 100
+// }
 
-fn make_move(acc: #(Int, Int), move: Int) -> #(Int, Int) {
+fn part2move(acc: #(Int, Int), move: Int) -> #(Int, Int) {
   let position = { acc.0 + move + 100 } % 100
+  let zeroes = case position {
+    0 -> acc.1 + 1
+    _ -> acc.1
+  }
+  #(position, zeroes)
+}
+
+fn part1move(acc: #(Int, Int), move: Int) -> #(Int, Int) {
+  let position =
+    { acc.0 + move + 100 } % 100
+    |> echo
   let zeroes = case position {
     0 -> acc.1 + 1
     _ -> acc.1

src/day2.gleam

···
+import gleam/int
+import gleam/io
+import gleam/list
+import gleam/regexp
+import gleam/string
+import herbie as h
+import simplifile
+
+pub fn day2main() {
+  let assert Ok(file) = simplifile.read("./data/day2")
+  let ranges =
+    file
+    |> string.trim()
+    |> string.split(",")
+    |> list.flat_map(fn(x) {
+      let assert [start, finish] = string.trim(x) |> string.split("-")
+      list.range(h.quickint(start), h.quickint(finish))
+    })
+
+  let part_1 =
+    list.filter(ranges, part1_filter)
+    |> list.fold(0, int.add)
+    |> int.to_string
+
+  let part_2 =
+    list.filter(ranges, part2_filter)
+    |> list.fold(0, int.add)
+    |> int.to_string
+
+  io.println("Part 1: " <> part_1 <> "\nPart 2: " <> part_2)
+}
+
+fn part2_filter(input: Int) -> Bool {
+  let pid = int.to_string(input)
+  let assert Ok(re) = regexp.from_string("^(\\d+)\\1+$")
+  regexp.check(re, pid)
+}
+
+fn part1_filter(input: Int) -> Bool {
+  let pid = int.to_string(input)
+  let is_even = string.length(pid) % 2 == 0
+  let half = string.slice(pid, 0, string.length(pid) / 2)
+  let halfsies = pid == half <> half
+  halfsies && is_even
+}