day 15, 16
This commit is contained in:
213
15/main.ml
Normal file
213
15/main.ml
Normal file
@@ -0,0 +1,213 @@
|
||||
open Printf;;
|
||||
|
||||
let rec list_of_lines in_file =
|
||||
try
|
||||
let line = input_line in_file in
|
||||
line :: list_of_lines(in_file)
|
||||
with End_of_file ->
|
||||
close_in in_file;
|
||||
[]
|
||||
|
||||
let lines_to_2d_array lines =
|
||||
let size_x = String.length @@ List.hd lines in
|
||||
let size_y = List.length lines in
|
||||
let arr = Array.make_matrix size_x size_y '?' in
|
||||
List.iteri (fun j line -> String.iteri (fun i c -> arr.(j).(i) <- c) line) lines;
|
||||
arr
|
||||
|
||||
let rec take_nonempty_lines lines =
|
||||
match lines with
|
||||
| head :: tail ->
|
||||
if String.length head = 0 then
|
||||
([], tail)
|
||||
else
|
||||
let rest_of_list, remaining_lines = take_nonempty_lines tail in
|
||||
(head :: rest_of_list, remaining_lines)
|
||||
| _ -> ([], lines)
|
||||
|
||||
let print_layout arr =
|
||||
arr
|
||||
|> Array.iter (fun row -> row
|
||||
|> Array.iter (fun x -> print_char x);
|
||||
print_endline "")
|
||||
|
||||
let rec find_index_inner elem arr pos =
|
||||
try
|
||||
if arr.(pos) = elem then
|
||||
Some pos
|
||||
else
|
||||
find_index_inner elem arr (pos + 1)
|
||||
with Invalid_argument _ -> None
|
||||
|
||||
let find_index elem arr =
|
||||
find_index_inner elem arr 0
|
||||
|
||||
let rec find_index_2d_inner elem arr pos =
|
||||
try
|
||||
match find_index elem arr.(pos) with
|
||||
| Some pos_x -> Some (pos_x, pos)
|
||||
| None -> find_index_2d_inner elem arr (pos + 1)
|
||||
with Invalid_argument _ -> None
|
||||
|
||||
let find_index_2d elem arr =
|
||||
find_index_2d_inner elem arr 0
|
||||
|
||||
let get_dir_vector dir =
|
||||
match dir with
|
||||
| '<' -> (-1, 0)
|
||||
| '>' -> (1, 0)
|
||||
| '^' -> (0, -1)
|
||||
| 'v' -> (0, 1)
|
||||
| _ -> raise (Invalid_argument "Invalid direction")
|
||||
|
||||
let add_int_pair (x1, y1) (x2, y2) =
|
||||
(x1 + x2, y1 + y2)
|
||||
|
||||
let rec skip_through_boxes (x, y) (dir_x, dir_y) arr =
|
||||
if arr.(y).(x) <> 'O' then
|
||||
(x, y)
|
||||
else
|
||||
let new_pos = add_int_pair (x, y) (dir_x, dir_y) in
|
||||
skip_through_boxes new_pos (dir_x, dir_y) arr
|
||||
|
||||
let robot_move arr pos dir =
|
||||
let dir_vector = get_dir_vector dir in
|
||||
let new_pos = add_int_pair pos dir_vector in
|
||||
let pos_behind_boxes = skip_through_boxes new_pos dir_vector arr in
|
||||
if arr.(snd pos_behind_boxes).(fst pos_behind_boxes) <> '#' then begin
|
||||
arr.(snd pos).(fst pos) <- '.';
|
||||
arr.(snd new_pos).(fst new_pos) <- '@';
|
||||
if new_pos <> pos_behind_boxes then
|
||||
arr.(snd pos_behind_boxes).(fst pos_behind_boxes) <- 'O';
|
||||
new_pos
|
||||
end else
|
||||
pos
|
||||
|
||||
let process_warehouse_tile c =
|
||||
match c with
|
||||
| '#' -> ['#'; '#']
|
||||
| 'O' -> ['['; ']']
|
||||
| '.' -> ['.'; '.']
|
||||
| '@' -> ['@'; '.']
|
||||
| _ -> raise (Invalid_argument "Invalid tile")
|
||||
|
||||
let process_warehouse arr =
|
||||
arr
|
||||
|> Array.map (fun row -> row
|
||||
|> Array.map process_warehouse_tile
|
||||
|> Array.to_seq
|
||||
|> List.of_seq
|
||||
|> List.concat
|
||||
|> List.to_seq
|
||||
|> Array.of_seq
|
||||
)
|
||||
|
||||
let rec try_push_horizontal (x, y) dir_x arr =
|
||||
let next_elem = arr.(y).(x) in
|
||||
if next_elem = '#' then
|
||||
false
|
||||
else if next_elem = '.' then
|
||||
true
|
||||
else
|
||||
let new_pos = (x + dir_x * 2, y) in
|
||||
if try_push_horizontal new_pos dir_x arr then begin
|
||||
let intermediate_pos = (x + dir_x, y) in
|
||||
arr.(snd new_pos).(fst new_pos) <- arr.(snd intermediate_pos).(fst intermediate_pos);
|
||||
arr.(snd intermediate_pos).(fst intermediate_pos) <- next_elem;
|
||||
true
|
||||
end else
|
||||
false
|
||||
|
||||
let rec possible_to_push_box_vertical (x, y) dir_y arr =
|
||||
let new_y = y + dir_y in
|
||||
possible_to_push_vertical (x, new_y) dir_y arr
|
||||
&& possible_to_push_vertical (x + 1, new_y) dir_y arr
|
||||
|
||||
and possible_to_push_vertical (x, y) dir_y arr =
|
||||
let next_elem = arr.(y).(x) in
|
||||
if next_elem = '#' then
|
||||
false
|
||||
else if next_elem = '.' then
|
||||
true
|
||||
else if next_elem = '[' then
|
||||
possible_to_push_box_vertical (x, y) dir_y arr
|
||||
else
|
||||
possible_to_push_box_vertical (x - 1, y) dir_y arr
|
||||
|
||||
let rec do_push_box_vertical (x, y) dir_y arr =
|
||||
let new_y = y + dir_y in begin
|
||||
do_push_vertical (x, new_y) dir_y arr;
|
||||
do_push_vertical (x + 1, new_y) dir_y arr;
|
||||
arr.(new_y).(x) <- '[';
|
||||
arr.(new_y).(x + 1) <- ']';
|
||||
arr.(y).(x) <- '.';
|
||||
arr.(y).(x + 1) <- '.'
|
||||
end
|
||||
|
||||
and do_push_vertical (x, y) dir_y arr =
|
||||
let next_elem = arr.(y).(x) in
|
||||
if next_elem = '#' || next_elem = '.' then
|
||||
()
|
||||
else if next_elem = '[' then
|
||||
do_push_box_vertical (x, y) dir_y arr
|
||||
else
|
||||
do_push_box_vertical (x - 1, y) dir_y arr
|
||||
|
||||
let try_push pos (dir_x, dir_y) arr =
|
||||
if dir_y = 0 then
|
||||
try_push_horizontal pos dir_x arr
|
||||
else
|
||||
if possible_to_push_vertical pos dir_y arr then begin
|
||||
do_push_vertical pos dir_y arr;
|
||||
true
|
||||
end else
|
||||
false
|
||||
|
||||
let robot_move_alt arr pos dir =
|
||||
let dir_vector = get_dir_vector dir in
|
||||
let new_pos = add_int_pair pos dir_vector in
|
||||
if try_push new_pos dir_vector arr then begin
|
||||
arr.(snd new_pos).(fst new_pos) <- '@';
|
||||
arr.(snd pos).(fst pos) <- '.';
|
||||
new_pos
|
||||
end else begin
|
||||
pos
|
||||
end
|
||||
|
||||
let array_copy_2d arr =
|
||||
Array.init (Array.length arr) (fun i -> Array.copy arr.(i))
|
||||
|
||||
let find_all_indices_of elem arr =
|
||||
arr |> Array.to_seq
|
||||
|> Seq.mapi (fun i x -> (i, x))
|
||||
|> Seq.filter_map (fun (i, x) -> if x = elem then Some i else None)
|
||||
|
||||
let find_all_indices_of_2d elem arr =
|
||||
arr |> Array.to_seq
|
||||
|> Seq.mapi (fun j row -> Seq.map (fun i -> (i, j)) (find_all_indices_of elem row))
|
||||
|> Seq.concat
|
||||
|
||||
let get_gps_index (x, y) =
|
||||
x + 100 * y
|
||||
|
||||
let () =
|
||||
let f = open_in "input.txt" in
|
||||
let layout_lines, remaining_lines = take_nonempty_lines @@ list_of_lines f in
|
||||
let arr = lines_to_2d_array layout_lines in
|
||||
let moves = String.concat "" remaining_lines in
|
||||
let pos = find_index_2d '@' arr |> Option.get in
|
||||
let warehouse1 = array_copy_2d arr in
|
||||
let _ = String.fold_left (robot_move warehouse1) pos moves in
|
||||
let result = warehouse1
|
||||
|> find_all_indices_of_2d 'O'
|
||||
|> Seq.map get_gps_index
|
||||
|> Seq.fold_left Int.add 0 in
|
||||
printf "%d\n" result;
|
||||
let warehouse2 = process_warehouse arr in
|
||||
let pos2 = find_index_2d '@' warehouse2 |> Option.get in
|
||||
let _ = String.fold_left (robot_move_alt warehouse2) pos2 moves in
|
||||
let result2 = warehouse2
|
||||
|> find_all_indices_of_2d '['
|
||||
|> Seq.map get_gps_index
|
||||
|> Seq.fold_left Int.add 0 in
|
||||
printf "%d\n" result2
|
||||
217
16/main.ml
Normal file
217
16/main.ml
Normal file
@@ -0,0 +1,217 @@
|
||||
open Printf;;
|
||||
|
||||
let rec list_of_lines in_file =
|
||||
try
|
||||
let line = input_line in_file in
|
||||
line :: list_of_lines(in_file)
|
||||
with End_of_file ->
|
||||
close_in in_file;
|
||||
[]
|
||||
|
||||
let lines_to_2d_array lines =
|
||||
let size_x = String.length @@ List.hd lines in
|
||||
let size_y = List.length lines in
|
||||
let arr = Array.make_matrix size_y size_x '?' in
|
||||
List.iteri (fun j line -> String.iteri (fun i c -> arr.(j).(i) <- c) line) lines;
|
||||
arr
|
||||
|
||||
let print_layout arr =
|
||||
arr
|
||||
|> Array.iter (fun row -> row
|
||||
|> Array.iter (fun x -> print_char x);
|
||||
print_endline "")
|
||||
|
||||
let rec find_index_inner elem arr pos =
|
||||
try
|
||||
if arr.(pos) = elem then
|
||||
Some pos
|
||||
else
|
||||
find_index_inner elem arr (pos + 1)
|
||||
with Invalid_argument _ -> None
|
||||
|
||||
let find_index elem arr =
|
||||
find_index_inner elem arr 0
|
||||
|
||||
let rec find_index_2d_inner elem arr pos =
|
||||
try
|
||||
match find_index elem arr.(pos) with
|
||||
| Some pos_x -> Some (pos_x, pos)
|
||||
| None -> find_index_2d_inner elem arr (pos + 1)
|
||||
with Invalid_argument _ -> None
|
||||
|
||||
let find_index_2d elem arr =
|
||||
find_index_2d_inner elem arr 0
|
||||
|
||||
let add_int_pair (x1, y1) (x2, y2) =
|
||||
(x1 + x2, y1 + y2)
|
||||
|
||||
let array_copy_2d arr =
|
||||
Array.init (Array.length arr) (fun i -> Array.copy arr.(i))
|
||||
|
||||
let find_all_indices_of elem arr =
|
||||
arr |> Array.to_seq
|
||||
|> Seq.mapi (fun i x -> (i, x))
|
||||
|> Seq.filter_map (fun (i, x) -> if x = elem then Some i else None)
|
||||
|
||||
let find_all_indices_of_2d elem arr =
|
||||
arr |> Array.to_seq
|
||||
|> Seq.mapi (fun j row -> Seq.map (fun i -> (i, j)) (find_all_indices_of elem row))
|
||||
|> Seq.concat
|
||||
|
||||
let rec chain_comparison comp1 comp2 arg1 arg2 =
|
||||
match comp1 arg1 arg2 with
|
||||
| 0 -> comp2 arg1 arg2
|
||||
| c -> c
|
||||
|
||||
type maze_walk_state = {
|
||||
pos: (int * int);
|
||||
dir: char;
|
||||
score: int
|
||||
}
|
||||
|
||||
module MazeWalkState =
|
||||
struct
|
||||
type t = maze_walk_state
|
||||
let compare arg0 arg1 =
|
||||
chain_comparison (fun arg1 arg2 -> Stdlib.compare arg1.score arg2.score) (
|
||||
chain_comparison (fun arg1 arg2 -> Stdlib.compare (fst arg1.pos) (fst arg2.pos)) (
|
||||
chain_comparison (fun arg1 arg2 -> Stdlib.compare (snd arg1.pos) (snd arg2.pos))
|
||||
(fun arg1 arg2 -> Stdlib.compare arg1.dir arg2.dir)
|
||||
)
|
||||
) arg0 arg1
|
||||
end
|
||||
module MazeWalkStateSet = Set.Make(MazeWalkState)
|
||||
module IntMap = Map.Make(Int)
|
||||
module IntSet = Set.Make(Int)
|
||||
|
||||
let get_dir_vector dir =
|
||||
match dir with
|
||||
| '<' -> (-1, 0)
|
||||
| '>' -> (1, 0)
|
||||
| '^' -> (0, -1)
|
||||
| 'v' -> (0, 1)
|
||||
| _ -> raise (Invalid_argument "Invalid direction")
|
||||
|
||||
let rotate_dir_right dir =
|
||||
match dir with
|
||||
| '<' -> '^'
|
||||
| '>' -> 'v'
|
||||
| '^' -> '>'
|
||||
| 'v' -> '<'
|
||||
| _ -> raise (Invalid_argument "Invalid direction")
|
||||
|
||||
let rotate_dir_left dir =
|
||||
match dir with
|
||||
| '<' -> 'v'
|
||||
| '>' -> '^'
|
||||
| '^' -> '<'
|
||||
| 'v' -> '>'
|
||||
| _ -> raise (Invalid_argument "Invalid direction")
|
||||
|
||||
let rotate_dir_back dir =
|
||||
match dir with
|
||||
| '<' -> '>'
|
||||
| '>' -> '<'
|
||||
| '^' -> 'v'
|
||||
| 'v' -> '^'
|
||||
| _ -> raise (Invalid_argument "Invalid direction")
|
||||
|
||||
let walk_forward state =
|
||||
{state with pos = add_int_pair state.pos (get_dir_vector state.dir); score = state.score + 1 }
|
||||
|
||||
let turn_right state =
|
||||
walk_forward {state with score = state.score + 1000; dir = rotate_dir_right state.dir}
|
||||
|
||||
let turn_left state =
|
||||
walk_forward {state with score = state.score + 1000; dir = rotate_dir_left state.dir}
|
||||
|
||||
let dir_index dir =
|
||||
match dir with
|
||||
| '<' -> 0
|
||||
| '>' -> 1
|
||||
| '^' -> 2
|
||||
| 'v' -> 3
|
||||
| _ -> raise (Invalid_argument "Invalid direction")
|
||||
|
||||
let generate_next_moves maze state =
|
||||
[walk_forward state; turn_left state; turn_right state]
|
||||
|> List.filter (fun state -> let (x, y) = state.pos in maze.(y).(x) <> '#')
|
||||
|
||||
let get_state_index maze {pos=(x, y); dir=dir; score=_} =
|
||||
((Array.length maze) * x + y) * 4 + (dir_index dir)
|
||||
|
||||
let state_index_remove_rotation state_index =
|
||||
state_index / 4
|
||||
|
||||
let decode_position_index maze position_index =
|
||||
let height = Array.length maze in
|
||||
(position_index / height, position_index mod height)
|
||||
|
||||
let add_prev maze prev_state next_state prev_move_map =
|
||||
let prev_index = get_state_index maze prev_state in
|
||||
let next_index = get_state_index maze next_state in
|
||||
let update_fun lst_opt =
|
||||
match lst_opt with
|
||||
| Some (score, lst) ->
|
||||
if next_state.score = score then
|
||||
Some (score, prev_index :: lst)
|
||||
else if next_state.score < score then
|
||||
Some (next_state.score, [prev_index])
|
||||
else
|
||||
Some (score, lst)
|
||||
| None -> Some (next_state.score, [prev_index]) in
|
||||
IntMap.update next_index update_fun prev_move_map
|
||||
|
||||
let worse_than_final_score final_score_opt score =
|
||||
match final_score_opt with
|
||||
| Some final_score -> score > final_score
|
||||
| None -> false
|
||||
|
||||
let rec dijkstra_find_path maze visited_array end_pos final_score_opt prev_move_map next_move_queue =
|
||||
match MazeWalkStateSet.min_elt_opt next_move_queue with
|
||||
| Some state ->
|
||||
let queue_with_removed = MazeWalkStateSet.remove state next_move_queue in
|
||||
if visited_array.(get_state_index maze state) then
|
||||
dijkstra_find_path maze visited_array end_pos final_score_opt prev_move_map queue_with_removed
|
||||
else
|
||||
if worse_than_final_score final_score_opt state.score then
|
||||
(Option.get final_score_opt, prev_move_map)
|
||||
else begin
|
||||
visited_array.(get_state_index maze state) <- true;
|
||||
let next_states = generate_next_moves maze state in
|
||||
let new_prev_move_map = List.fold_left (fun map s -> add_prev maze state s map) prev_move_map next_states in
|
||||
let solution_states = List.filter (fun s -> s.pos = end_pos) next_states in
|
||||
if List.length solution_states > 0 then
|
||||
let final_score = (List.hd solution_states).score in
|
||||
dijkstra_find_path maze visited_array end_pos (Some final_score) new_prev_move_map queue_with_removed
|
||||
else
|
||||
let new_queue = List.fold_left (fun queue s -> MazeWalkStateSet.add s queue) queue_with_removed next_states in
|
||||
dijkstra_find_path maze visited_array end_pos final_score_opt new_prev_move_map new_queue
|
||||
end
|
||||
| None -> (-1, prev_move_map)
|
||||
|
||||
let rec backtrack_and_fill_position_set prev_move_map state_index pos_set =
|
||||
let new_pos_set = IntSet.add (state_index_remove_rotation state_index) pos_set in
|
||||
match IntMap.find_opt state_index prev_move_map with
|
||||
| Some (_, prev_list) ->
|
||||
List.fold_left (fun set idx -> backtrack_and_fill_position_set prev_move_map idx set) new_pos_set prev_list
|
||||
| None -> new_pos_set
|
||||
|
||||
let count_tiles_on_best_paths maze end_pos prev_move_map =
|
||||
['<'; '>'; '^'; 'v']
|
||||
|> List.map (fun dir -> get_state_index maze {pos=end_pos; dir=dir; score=0})
|
||||
|> List.fold_left (fun set state_index -> backtrack_and_fill_position_set prev_move_map state_index set) IntSet.empty
|
||||
|
||||
let find_best_path maze start_pos end_pos =
|
||||
let visited_array = Array.make ((Array.length maze) * (Array.length maze.(0) * 4)) false in
|
||||
let start_state = {pos=start_pos; dir='>'; score=0} in
|
||||
dijkstra_find_path maze visited_array end_pos None IntMap.empty (MazeWalkStateSet.add start_state MazeWalkStateSet.empty)
|
||||
|
||||
let () =
|
||||
let f = open_in "input.txt" in
|
||||
let maze = lines_to_2d_array @@ list_of_lines f in
|
||||
let start_pos = find_index_2d 'S' maze |> Option.get in
|
||||
let end_pos = find_index_2d 'E' maze |> Option.get in
|
||||
let (result, prev_move_map) = find_best_path maze start_pos end_pos in
|
||||
let result2 = prev_move_map |> count_tiles_on_best_paths maze end_pos |> IntSet.cardinal in
|
||||
printf "%d\n%d\n" result result2
|
||||
Reference in New Issue
Block a user