1 files changed, 49 insertions, 1 deletions
diff --git a/2025/ocaml/lib/application/day_1.ml b/2025/ocaml/lib/application/day_1.ml
index 7ddac8b..bc0d5cc 100644
--- a/2025/ocaml/lib/application/day_1.ml
+++ b/2025/ocaml/lib/application/day_1.ml
@@ -1 +1,49 @@
-let run () = failwith "day 1 not implemented"
+open Domain.Day_1
+
+let rec input_to_lines input =
+  let lines =
+    String.split_on_char '\n' input |> List.filter (fun l -> l <> "")
+  in
+  pp_lines lines ; lines
+
+and pp_lines = function
+  | [] ->
+      ()
+  | h :: t ->
+      Logs.debug (fun m -> m "Line=%s" h) ;
+      pp_lines t
+
+let parse_line line =
+  Scanf.sscanf line "%c%d" (fun d n ->
+      match d with
+      | 'L' ->
+          Dial.Left n
+      | 'R' ->
+          Dial.Right n
+      | _ ->
+          failwith "invalid direction" )
+
+let lines_to_turns =
+  List.map (fun (l : string) ->
+      Logs.debug (fun m -> m "parsing %s into turn" l) ;
+      let turn = parse_line l in
+      Logs.debug (fun m -> m "%s" (Dial.pp_direction turn)) ;
+      turn )
+
+let rec turn_aux count current = function
+  | [] ->
+      count
+  | h :: t ->
+      let current' = Dial.turn current h in
+      Logs.debug (fun m -> m "dial at %d" (Dial.to_int current')) ;
+      if Dial.to_int current' = 0 then turn_aux (count + 1) current' t
+      else turn_aux count current' t
+
+let turn current = turn_aux 0 current
+
+let solve input () =
+  let lines = input_to_lines input in
+  let turns = lines_to_turns lines in
+  let start = Dial.start in
+  let answer = turn start turns in
+  answer