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just keep the strings

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This commit is contained in:
Rhiannon Morris 2020-12-03 16:40:21 +01:00
parent e0b2dfe566
commit 3c2e61176a
1 changed files with 10 additions and 22 deletions
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32
day3.ml
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@ -1,38 +1,26 @@
type space = Tree | Free type map = string array
type map = space array array
let (.%()) arr i = arr.(i mod Array.length arr) let (.%[]) str i = str.[i mod String.length str]
let (+=) r x = r := !r + x
let iter_map ?(step_x=1) ?(step_y=1) f arr = let iter_map ?(step_x=1) ?(step_y=1) f arr =
let i = ref 0 in let i = ref 0 in let j = ref 0 in
let j = ref 0 in
while !i < Array.length arr do while !i < Array.length arr do
f arr.(!i).%(!j); f arr.(!i).%[!j];
i := !i + step_x; i += step_x; j += step_y
j := !j + step_y
done done
exception Unknown_char of char let read_file = Bracket.infile_lines ~line:Fun.id ~of_seq:Array.of_seq
let make_line str =
Array.init (String.length str)
(fun i -> match str.[i] with
| '#' -> Tree
| '.' -> Free
| c -> raise (Unknown_char c))
let read_file = Bracket.infile_lines ~line:make_line ~of_seq:Array.of_seq
let count_trees ?step_x ?step_y map = let count_trees ?step_x ?step_y map =
let count = ref 0 in let count = ref 0 in
iter_map ?step_x ?step_y (function Tree -> incr count | _ -> ()) map; iter_map ?step_x ?step_y (fun c -> if c = '#' then incr count) map;
!count !count
let main1 input = let main1 input =
Format.printf "%d trees\n" Format.printf "%d\n" (count_trees ~step_y:3 (read_file input))
(count_trees ~step_y:3 (read_file input))
let main2 input = let main2 input =
let map = read_file input in let map = read_file input in
@ -47,7 +35,7 @@ let main = Misc.main 3 [|main1; main2|]
let%expect_test _ = let%expect_test _ =
main1 "../../data/day3"; main1 "../../data/day3";
[%expect{| 244 trees |}] [%expect{| 244 |}]
let%expect_test _ = let%expect_test _ =
main2 "../../data/day3"; main2 "../../data/day3";