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Move to use Aoc.Grid

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This commit is contained in:
Matthew Gretton-Dann
2024-12-10 11:31:37 +00:00
parent fe93f65f6a
commit b2e56f802e
3 changed files with 25 additions and 94 deletions
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44
bin/day2410.ml
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@@ -1,33 +1,3 @@
type grid = { grid : string; width : int; height : int }
(** Type to hold the grid in... We should be moving this to the library soon *)
(** [grid_of_file fname] loads a grid from the given file *)
let grid_of_file fname =
let strs = Aoc.strings_of_file fname in
let grid = List.fold_left String.cat "" strs in
let width = String.length (List.hd strs) in
let height = String.length grid / width in
assert (width * height = String.length grid);
{ grid; width; height }
(** [grid_length grid] gives the length of the grid ([width * height]). *)
let grid_length grid = String.length grid.grid
(** [grid_get_by_idx grid idx] returns the element of [grid] at [idx]. *)
let grid_get_by_idx grid idx = grid.grid.[idx]
(** [grid_get_by_idx grid pos] returns the element of [grid] at [pos]. *)
let grid_get_by_pos grid (x, y) = grid.grid.[x + (y * grid.width)]
(** [grid_pos_if_idx grid idx] returns the [(x, y)] position of [idx] in [grid].
*)
let grid_pos_of_idx grid idx = (idx mod grid.width, idx / grid.width)
(** [grid_pos_is_valid grid pos] returns [true] if and only if [pos] is a valid
position in [grid]. *)
let grid_pos_is_valid grid (x, y) =
x >= 0 && y >= 0 && x < grid.width && y < grid.height
(** [next_char ch] returns the next character after [ch]. *)
let next_char ch = Char.chr (1 + Char.code ch)
@@ -42,10 +12,10 @@ let one = '1'
'0'. The same endpoint may be returned multiple times if there are multiple
routes to it. *)
let find_trail grid pos0 =
assert (grid_get_by_pos grid pos0 = '0');
assert (Aoc.Grid.get_by_pos grid pos0 = '0');
let add_pos lst pos digit =
if grid_pos_is_valid grid pos && grid_get_by_pos grid pos = digit then
pos :: lst
if Aoc.Grid.pos_is_valid grid pos && Aoc.Grid.get_by_pos grid pos = digit
then pos :: lst
else lst
in
let add_poses lst (x, y) digit =
@@ -69,10 +39,10 @@ let find_trail grid pos0 =
corresponds to the trails starting at index [n]. *)
let find_trails grid =
let rec impl acc idx =
if idx >= grid_length grid then acc
else if grid_get_by_idx grid idx <> '0' then impl acc (idx + 1)
if idx >= Aoc.Grid.length grid then acc
else if Aoc.Grid.get_by_idx grid idx <> '0' then impl acc (idx + 1)
else (* grid_get_by_idx grid idx = 0 *)
impl (find_trail grid (grid_pos_of_idx grid idx) :: acc) (idx + 1)
impl (find_trail grid (Aoc.Grid.pos_of_idx grid idx) :: acc) (idx + 1)
in
impl [] 0 |> List.rev
@@ -83,7 +53,7 @@ let part sort_fn grid =
|> List.fold_left ( + ) 0
let _ =
Aoc.main grid_of_file
Aoc.main Aoc.Grid.of_file
[
(string_of_int, part (List.sort_uniq Stdlib.compare));
(string_of_int, part Fun.id);