blob: dadd60aba608d70899f42f9ddaeac30a20fa0614 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
|
module M : sig
type 'a t = 'a array array
val empty : int -> int -> 'a -> 'a t
(** [empty rows columns initial] is an empty 2D array of size [rows] * [columns]
where each element in the array is initialized to [initial]. *)
val of_list : 'a list list -> 'a t
(** [of_list lst] is a 2D array where every element in the array is an
element corresponds to an element of the [lst]. *)
val to_list : 'a t -> 'a list list
(** [to_list matrix] is a 2D list where every element in the list is an
element corresponds to an element of the [matrix]. *)
val of_string : string -> string t
(** [of_string str] is a 2D array where every character is an element. *)
val get : 'a t -> int -> int -> 'a
(** [get matrix x y] is an alias for [matrix.(y).(x)].
Requires: [x] and [y] are positive integers or 0. *)
val set : 'a t -> int -> int -> 'a -> unit
(** [set matrix x y v] is an alias for [matrix.(y).(x) <- v].
Requires: [x] and [y] are positive integers or 0. *)
val get_valid_neighbours : 'a t -> int -> int -> (int * int) list
(** [get_valid_neighbours matrix x y] is a list of pairs in the format
(x * y) that represent the valid surrounding positions of [matrix.(y).(x)].
Requires: [x] and [y] are positive integers or 0. *)
val pp : ('a -> string) -> 'a t -> string
(** [pp matrix string_of_elt] is the string representation of the [matrix]
where [string_of_elt] is called on each element. *)
end = struct
type 'a t = 'a array array
let empty cols rows initial = Array.make_matrix cols rows initial
let of_list lst = Array.of_list @@ List.map Array.of_list lst
let to_list matrix = Array.to_list @@ Array.map Array.to_list matrix
let of_string str =
let lines =
str |> String.split_on_char '\n'
|> List.filter_map (fun line ->
let trimmed = String.trim line in
if trimmed <> "" then Some trimmed else None )
in
let char_lst =
List.map
(fun s -> s |> String.to_seq |> List.of_seq |> List.map Char.escaped)
lines
in
of_list char_lst
let get matrix x y = matrix.(y).(x)
let set matrix x y v = matrix.(y).(x) <- v
let get_valid_neighbours matrix x y =
let potential_neighbours =
[ (x - 1, y - 1)
; (x, y - 1)
; (x + 1, y - 1)
; (x - 1, y)
; (x + 1, y)
; (x - 1, y + 1)
; (x, y + 1)
; (x + 1, y + 1) ]
in
let min_x = 0 in
let max_x = Array.length matrix.(y) - 1 in
let min_y = 0 in
let max_y = Array.length matrix - 1 in
List.filter
(fun (x, y) -> min_x <= x && x <= max_x && min_y <= y && y <= max_y)
potential_neighbours
let pp string_of_elt matrix =
"["
^ Array.fold_left
(fun col_acc arr ->
let row =
"["
^ Array.fold_left
(fun row_acc elt -> row_acc ^ string_of_elt elt ^ "; ")
" " arr
^ "]"
in
col_acc ^ " " ^ row ^ "\n" )
"\n" matrix
^ "]"
end
let%expect_test "matrix created from input is pretty-printed as the same matrix"
=
let example =
{|..@@.@@@@.
@@@.@.@.@@
@@@@@.@.@@
@.@@@@..@.
@@.@@@@.@@
.@@@@@@@.@
.@.@.@.@@@
@.@@@.@@@@
.@@@@@@@@.
@.@.@@@.@.|}
in
print_string @@ M.pp (fun s -> s) @@ M.of_string example ;
[%expect
{|..@@.@@@@.
@@@.@.@.@@
@@@@@.@.@@
@.@@@@..@.
@@.@@@@.@@
.@@@@@@@.@
.@.@.@.@@@
@.@@@.@@@@
.@@@@@@@@.
@.@.@@@.@.|}]
let%expect_test "direct access of the matrix is in form matrix.(y).(x)" =
let example =
{|..@@.@@@@.
@@@.@.@.@@
@@@@@.@.@@
@.@@@@..@.
@@.@@@@.@@
.@@@@@@@.@
.@.@.@.@@@
@.@@@.@@@@
.@@@@@@@@.
@.@.@@@.@.|}
in
let matrix = M.of_string example in
print_string matrix.(0).(0) ;
[%expect "."] ;
print_string matrix.(0).(1) ;
[%expect "."] ;
print_string matrix.(0).(2) ;
[%expect "@"] ;
print_string matrix.(0).(3) ;
[%expect "@"] ;
print_string matrix.(0).(4) ;
[%expect "."] ;
print_string matrix.(0).(5) ;
[%expect "@"] ;
print_string matrix.(0).(6) ;
[%expect "@"] ;
print_string matrix.(0).(7) ;
[%expect "@"] ;
print_string matrix.(0).(8) ;
[%expect "@"] ;
print_string matrix.(0).(9) ;
[%expect "."]
let%expect_test "[M.get matrix x y] is an alias for [matrix.(y).(x)]" =
let example =
{|..@@.@@@@.
@@@.@.@.@@
@@@@@.@.@@
@.@@@@..@.
@@.@@@@.@@
.@@@@@@@.@
.@.@.@.@@@
@.@@@.@@@@
.@@@@@@@@.
@.@.@@@.@.|}
in
let matrix = M.of_string example in
print_string @@ M.get matrix 0 0 ;
[%expect "."] ;
print_string @@ M.get matrix 1 0 ;
[%expect "."] ;
print_string @@ M.get matrix 2 0 ;
[%expect "@"] ;
print_string @@ M.get matrix 3 0 ;
[%expect "@"] ;
print_string @@ M.get matrix 4 0 ;
[%expect "."] ;
print_string @@ M.get matrix 5 0 ;
[%expect "@"] ;
print_string @@ M.get matrix 6 0 ;
[%expect "@"] ;
print_string @@ M.get matrix 7 0 ;
[%expect "@"] ;
print_string @@ M.get matrix 8 0 ;
[%expect "@"] ;
print_string @@ M.get matrix 9 0 ;
[%expect "."]
|
