ocaml day 1 done

1 files changed, 32 insertions, 0 deletions

diff --git a/2024/day_01.ml b/2024/day_01.ml
new file mode 100644
index 0000000..42ee50d
--- /dev/null
+++ b/2024/day_01.ml
@@ -0,0 +1,32 @@
+let filename = "./day_01_input.txt"
+
+let () =
+  let ic = open_in filename in
+
+  let try_read () = try Some (input_line ic) with End_of_file -> None in
+
+  let rec read_lines left right =
+    match try_read () with
+    | Some line -> (
+        let ints =
+          Str.split_delim (Str.regexp "   ") line |> List.map int_of_string
+        in
+        match ints with
+        | [ a; b ] -> read_lines (a :: left) (b :: right)
+        | _ -> failwith "invalid")
+    | None ->
+        close_in ic;
+        (List.sort compare left, List.sort compare right)
+  in
+  let left, right = read_lines [] [] in
+  let sum =
+    List.map2 ( - ) left right |> List.map abs |> List.fold_left ( + ) 0
+  in
+  Printf.sprintf "Sum %d" sum |> print_endline;
+  let sim =
+    List.map
+      (fun x -> x * (List.filter (fun y -> x == y) right |> List.length))
+      left
+    |> List.fold_left ( + ) 0
+  in
+  Printf.sprintf "Sim %d" sim |> print_endline