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(*
* SPDX-FileCopyrightText: Copyright 2025 Alexandre Jesus <https://adbjesus.com>
*
* SPDX-License-Identifier: GPL-3.0-or-later
*)
type puzzle = { n : int; m : int; q : int list }
type shape = { n : int; m : int; g : bool array array }
let parse ch =
let parse_puzzle s =
let d = String.trim s |> String.split_on_char ':' in
match d with
| sz :: (q :: []) ->
let n, m = Scanf.sscanf sz "%dx%d" (fun n m -> (n, m)) in
let q = String.trim q |> String.split_on_char ' ' |> List.map int_of_string in
{ n; m; q}
| _ -> failwith ("Invalid puzzle: "^s)
in
let rec parse_shape l acc =
let make_res tl =
let g = List.rev acc |> Array.of_list in
let n = Array.length g in
let m = Array.length g.(0) in
(tl, { n; m; g })
in
match l with
| [] -> make_res []
| "" :: tl -> make_res tl
| line :: tl ->
let gl = String.to_seq line |> Seq.map (fun c -> c = '#') |> Array.of_seq in
parse_shape tl (gl :: acc)
in
let rec parse_all shapes puzzles l =
match l with
| [] -> (List.rev shapes, List.rev puzzles)
| "" :: tl -> parse_all shapes puzzles tl
| s :: tl ->
match Scanf.sscanf_opt s "%d:" (fun _ -> parse_shape tl []) with
| Some (l, shape) -> parse_all (shape :: shapes) puzzles l
| None -> parse_all shapes ((parse_puzzle s) :: puzzles) tl
in
In_channel.input_lines ch
|> parse_all [] []
let solve_naive shapes puzzle =
(* This is NOT a solution to the general problem, but is enough for the given input *)
List.map2 (fun s c -> s.n * s.m * c) shapes puzzle.q
|> List.fold_left ( + ) 0
|> fun a -> if a <= puzzle.n * puzzle.m then 1 else 0
let part1 ch =
let shapes, puzzles = parse ch in
List.map (solve_naive shapes) puzzles
|> List.fold_left ( + ) 0
|> Printf.printf "%d\n"
|
