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diff --git a/lib/day10.ml b/lib/day10.ml
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+(*
+ * SPDX-FileCopyrightText: Copyright 2025 Alexandre Jesus <https://adbjesus.com>
+ *
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ *)
+
+open Glpk.C.Functions
+open Glpk.C.Types
+
+type machine = { lights : int; buttons : int list list; ibuttons : int list; joltage : int list }
+
+let parse_machine s =
+  let a = String.split_on_char ' ' s in
+  let lights =
+    List.hd a
+    |> String.fold_left
+         (fun acc c ->
+           match c with
+           | '.' -> acc * 2
+           | '#' -> (acc * 2) + 1
+           | '[' | ']' -> acc
+           | _ -> failwith (Printf.sprintf "Wrong data: %s" s))
+         0
+  in
+  let nlights = String.length (List.hd a) - 2 in
+  let parse_button s =
+    if s.[0] = '(' then
+      let sub = String.sub s 1 (String.length s - 2) in
+      Some (String.split_on_char ',' sub |> List.map int_of_string)
+    else None
+  in
+  let parse_ibutton b =
+    b
+    |> List.map (fun v ->
+           let v = nlights - v - 1 in
+           Int.shift_left 1 v)
+    |> List.fold_left ( + ) 0
+  in
+  let buttons = List.filter_map parse_button (List.tl a) in
+  let ibuttons = List.map parse_ibutton buttons in
+  let joltage = List.rev a |> List.hd in
+  let joltage = String.sub joltage 1 (String.length joltage - 2) in
+  let joltage = String.split_on_char ',' joltage |> List.map int_of_string in
+  { lights; buttons; ibuttons; joltage }
+
+let print_machines machines =
+  List.iter
+    (fun machine ->
+      Printf.printf "%d ->" machine.lights;
+      List.iter (Printf.printf " %d") machine.ibuttons;
+      Printf.printf " ->";
+      List.iter (Printf.printf " %d") machine.joltage;
+      Printf.printf "\n")
+    machines
+
+let parse ch = ch |> In_channel.input_lines |> List.map parse_machine
+
+let part1 ch =
+  let machines = parse ch in
+  let solve machine =
+    let rec fn v c bs =
+      if v = machine.lights then c
+      else
+        match bs with
+        | [] -> Int.max_int
+        | b :: bt -> Int.min (fn (Int.logxor v b) (c + 1) bt) (fn v c bt)
+    in
+    fn 0 0 machine.ibuttons
+  in
+  List.map solve machines |> List.fold_left ( + ) 0 |> Printf.printf "%d\n"
+
+let part2 ch =
+  let machines = parse ch in
+  let solve machine =
+    let p = glp_create_prob () in
+    let n = List.length machine.joltage in
+    let m = List.length machine.buttons in
+    glp_set_obj_dir p glp_min;
+    glp_add_rows p n;
+    machine.joltage
+    |> List.to_seq
+    |> Seq.map Float.of_int
+    |> Seq.iteri (fun i v -> glp_set_row_bnds p (i + 1) glp_fx v v);
+    glp_add_cols p m;
+    for i = 1 to m do
+      glp_set_col_bnds p i glp_lo 0.0 0.0;
+      glp_set_col_kind p i glp_iv;
+      glp_set_obj_coef p i 1.0;
+    done;
+    (machine.buttons
+     |> List.iteri
+       (fun i b ->
+         let len = List.length b in
+         let ind = 0 :: (List.map (( + ) 1) b) |> Ctypes.CArray.of_list Ctypes.int in
+         let vals = Ctypes.CArray.make Ctypes.double ~initial:1.0 (len + 1) in
+         glp_set_mat_col p (i + 1) len (Ctypes.CArray.start ind) (Ctypes.CArray.start vals)
+    ));
+    glp_simplex p Ctypes.null;
+    glp_intopt p Ctypes.null;
+    (if (glp_mip_status p) <> glp_opt then
+      failwith "Infeasible ILP");
+    let ans = glp_mip_obj_val p in
+    glp_delete_prob p;
+    Int.of_float (ans +. 0.1)
+  in
+  ignore (glp_term_out glp_off);
+  machines
+  |> List.map solve
+  |> List.fold_left ( + ) 0
+  |> Printf.printf "%d\n"