2024-03 * ** Gleam

gleam.toml

@@ -16,6 +16,7 @@ version = "1.0.0"
 gleam_stdlib = ">= 0.34.0 and < 2.0.0"
 gladvent = ">= 2.0.2 and < 3.0.0"
 gleam_otp = ">= 0.14.1 and < 1.0.0"
+gleam_regexp = ">= 1.0.0 and < 2.0.0"
 
 [dev-dependencies]
 gleeunit = ">= 1.0.0 and < 2.0.0"

manifest.toml

@@ -12,6 +12,7 @@ packages = [
   { name = "gleam_json", version = "2.1.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_json", source = "hex", outer_checksum = "0A57FB5666E695FD2BEE74C0428A98B0FC11A395D2C7B4CDF5E22C5DD32C74C6" },
   { name = "gleam_otp", version = "0.14.1", build_tools = ["gleam"], requirements = ["gleam_erlang", "gleam_stdlib"], otp_app = "gleam_otp", source = "hex", outer_checksum = "5A8CE8DBD01C29403390A7BD5C0A63D26F865C83173CF9708E6E827E53159C65" },
   { name = "gleam_package_interface", version = "1.1.0", build_tools = ["gleam"], requirements = ["gleam_json", "gleam_stdlib"], otp_app = "gleam_package_interface", source = "hex", outer_checksum = "CF3BFC5D0997750D9550D8D73A90F4B8D71C6C081B20ED4E70FFBE1E99AFC3C2" },
+  { name = "gleam_regexp", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleam_regexp", source = "hex", outer_checksum = "A3655FDD288571E90EE9C4009B719FEF59FA16AFCDF3952A76A125AF23CF1592" },
   { name = "gleam_stdlib", version = "0.45.0", build_tools = ["gleam"], requirements = [], otp_app = "gleam_stdlib", source = "hex", outer_checksum = "206FCE1A76974AECFC55AEBCD0217D59EDE4E408C016E2CFCCC8FF51278F186E" },
   { name = "glearray", version = "1.0.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "glearray", source = "hex", outer_checksum = "B99767A9BC63EF9CC8809F66C7276042E5EFEACAA5B25188B552D3691B91AC6D" },
   { name = "gleeunit", version = "1.2.0", build_tools = ["gleam"], requirements = ["gleam_stdlib"], otp_app = "gleeunit", source = "hex", outer_checksum = "F7A7228925D3EE7D0813C922E062BFD6D7E9310F0BEE585D3A42F3307E3CFD13" },
@@ -28,5 +29,6 @@ packages = [
 [requirements]
 gladvent = { version = ">= 2.0.2 and < 3.0.0" }
 gleam_otp = { version = ">= 0.14.1 and < 1.0.0" }
+gleam_regexp = { version = ">= 1.0.0 and < 2.0.0" }
 gleam_stdlib = { version = ">= 0.34.0 and < 2.0.0" }
 gleeunit = { version = ">= 1.0.0 and < 2.0.0" }

src/aoc_2024/day_3.gleam

@@ -0,0 +1,69 @@
+import extra
+import gleam/int
+import gleam/list
+import gleam/regexp
+import gleam/string
+
+pub type Op {
+  Mul(Int, Int)
+  Do
+  Dont
+}
+
+fn from_match(match: regexp.Match) -> Op {
+  case match.content {
+    "mul(" <> rest -> {
+      let assert Ok(strs) =
+        rest
+        |> string.drop_end(1)
+        |> string.split_once(",")
+      Mul(extra.yolo_int(strs.0), extra.yolo_int(strs.1))
+    }
+    "do()" -> Do
+    "don't()" -> Dont
+    _ -> panic as "Bad input"
+  }
+}
+
+pub fn parse(input: String) -> List(Op) {
+  let assert Ok(regex) =
+    regexp.from_string("mul\\(\\d+,\\d+\\)|do\\(\\)|don't\\(\\)")
+
+  regex
+  |> regexp.scan(input)
+  |> list.map(from_match)
+}
+
+pub fn pt_1(ops: List(Op)) {
+  ops
+  |> list.map(fn(op) {
+    case op {
+      Mul(x, y) -> x * y
+      Do -> 0
+      Dont -> 0
+    }
+  })
+  |> int.sum
+}
+
+type State {
+  State(sum: Int, can_mult: Bool)
+}
+
+pub fn pt_2(ops: List(Op)) {
+  let result =
+    ops
+    |> list.fold(State(0, True), fn(acc, op) {
+      case op {
+        Mul(x, y) ->
+          case acc.can_mult {
+            True -> State(..acc, sum: acc.sum + x * y)
+            False -> acc
+          }
+        Do -> State(..acc, can_mult: True)
+        Dont -> State(..acc, can_mult: False)
+      }
+    })
+
+  result.sum
+}