also solve day 2 using gleam

2024/gleam/gleam.toml

@@ -14,6 +14,4 @@ version = "1.0.0"
 
 [dependencies]
 gleam_stdlib = ">= 0.34.0 and < 2.0.0"
-
-[dev-dependencies]
-gleeunit = ">= 1.0.0 and < 2.0.0"
+stdin = ">= 1.1.4 and < 2.0.0"

2024/gleam/manifest.toml

@@ -0,0 +1,11 @@
+# This file was generated by Gleam
+# You typically do not need to edit this file
+
+packages = [
+  { name = "gleam_stdlib", version = "0.45.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "206FCE1A76974AECFC55AEBCD0217D59EDE4E408C016E2CFCCC8FF51278F186E" },
+  { name = "stdin", version = "1.1.4", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "stdin", source = "hex", outer_checksum = "04C04035F2A4CEEFB023837249649CD25F9A9CF5A45F9947C4D0462428A4677D" },
+]
+
+[requirements]
+gleam_stdlib = { version = ">= 0.34.0 and < 2.0.0" }
+stdin = { version = ">= 1.1.4 and < 2.0.0" }

2024/gleam/src/aoc/day_two.gleam

@@ -0,0 +1,58 @@
+import gleam/int
+import gleam/io
+import gleam/iterator
+import gleam/list
+import gleam/pair
+import gleam/result
+import gleam/string
+import stdin.{stdin}
+
+type Report =
+  List(Int)
+
+pub fn main() {
+  let reports = stdin() |> iterator.to_list() |> list.map(with: parse_report)
+
+  let part1 = list.count(reports, is_safe) |> int.to_string()
+  let part2 = list.count(reports, is_safe_with_damper) |> int.to_string()
+
+  io.print("Part 1: ")
+  io.println(part1)
+  io.print("Part 2: ")
+  io.println(part2)
+}
+
+fn is_safe(report: Report) -> Bool {
+  let diffs =
+    report
+    |> list.window_by_2()
+    |> list.map(fn(p) { pair.first(p) - pair.second(p) })
+
+  list.all(diffs, fn(n) { 1 <= n && n <= 3 })
+  || list.all(diffs, fn(n) { -3 <= n && n <= -1 })
+}
+
+fn is_safe_with_damper(report: Report) -> Bool {
+  is_safe(report)
+  || report
+  |> reports_with_a_single_level_removed()
+  |> list.any(is_safe)
+}
+
+fn reports_with_a_single_level_removed(report: Report) -> List(Report) {
+  let len = list.length(report)
+  let idxs = list.range(0, len - 1)
+
+  use i <- list.map(idxs)
+  let assert #(head, [_, ..tail]) = list.split(report, i)
+  list.append(head, tail)
+}
+
+fn parse_report(str: String) -> Report {
+  str
+  |> string.trim()
+  |> string.split(" ")
+  |> list.map(int.parse)
+  |> result.all()
+  |> result.unwrap([])
+}