yemou.pink
+1
2015/06/part1-tests/input1
+1
2015/06/part1-tests/input1
···
1
+
turn on 0,0 through 999,999
+1
2015/06/part1-tests/input2
+1
2015/06/part1-tests/input2
···
1
+
toggle 0,0 through 999,0
+2
2015/06/part1-tests/input4
+2
2015/06/part1-tests/input4
+1
2015/06/part1-tests/input5
+1
2015/06/part1-tests/input5
···
1
+
turn off 499,499 through 500,500
+1
2015/06/part2-tests/input1
+1
2015/06/part2-tests/input1
···
1
+
turn on 0,0 through 0,0
+1
2015/06/part2-tests/input2
+1
2015/06/part2-tests/input2
···
1
+
toggle 0,0 through 999,999
+103
2015/06/solution.erl
+103
2015/06/solution.erl
···
1
+
#!/usr/bin/env escript
2
+
% --- Part 1 Code
3
+
part1(Input) -> io:format("Part 1: ~b~n", [count_lit_lights(Input, #{})]).
4
+
5
+
generate_coordinates({XStart, YStart}, {XEnd, YEnd}) ->
6
+
[{X, Y} || X <- lists:seq(XStart, XEnd), Y <- lists:seq(YStart, YEnd)].
7
+
8
+
generate_map(Coords, Value) -> maps:from_list([{Coord, Value} || Coord <- Coords]).
9
+
10
+
perform_instruction(toggle, Coords, Map) ->
11
+
maps:merge_with(
12
+
fun(_, Current, _) ->
13
+
case Current of
14
+
0 -> 1;
15
+
1 -> 0
16
+
end
17
+
end,
18
+
Map,
19
+
generate_map(Coords, 1)
20
+
);
21
+
perform_instruction(Action, Coords, Map) ->
22
+
maps:merge(
23
+
Map,
24
+
case Action of
25
+
on -> generate_map(Coords, 1);
26
+
off -> generate_map(Coords, 0)
27
+
end
28
+
).
29
+
30
+
count_lit_lights([], Map) ->
31
+
maps:fold(fun(_, Value, Accumulator) -> Accumulator + Value end, 0, Map);
32
+
count_lit_lights([{Action, Start, End} | Instructions], Map) ->
33
+
count_lit_lights(
34
+
Instructions,
35
+
perform_instruction(Action, generate_coordinates(Start, End), Map)
36
+
).
37
+
38
+
% --- Part 2 Code
39
+
part2(Input) -> io:format("Part 2: ~b~n", [calculate_brightness(Input, #{})]).
40
+
41
+
perform_instruction2(off, Coords, Map) ->
42
+
maps:merge_with(
43
+
fun(_, Current, _) ->
44
+
case Current of
45
+
Current when Current > 0 -> Current - 1;
46
+
Current -> 0
47
+
end
48
+
end,
49
+
Map,
50
+
generate_map(Coords, 0)
51
+
);
52
+
perform_instruction2(Action, Coords, Map) ->
53
+
maps:merge_with(
54
+
fun(_, Current, New) -> Current + New end,
55
+
Map,
56
+
case Action of
57
+
toggle -> generate_map(Coords, 2);
58
+
on -> generate_map(Coords, 1)
59
+
end
60
+
).
61
+
62
+
calculate_brightness([], Map) ->
63
+
maps:fold(fun(_, Value, Accumulator) -> Accumulator + Value end, 0, Map);
64
+
calculate_brightness([{Action, Start, End} | Instructions], Map) ->
65
+
calculate_brightness(
66
+
Instructions,
67
+
perform_instruction2(Action, generate_coordinates(Start, End), Map)
68
+
).
69
+
70
+
% --- Read Input
71
+
split_coordinate(Coordinate) ->
72
+
[X, Y] = string:split(Coordinate, ","),
73
+
{Xint, _} = string:to_integer(X),
74
+
{Yint, _} = string:to_integer(Y),
75
+
{Xint, Yint}.
76
+
77
+
parse_line(Data) ->
78
+
case string:split(string:trim(Data), " ", all) of
79
+
["toggle", Start, _, End] -> {toggle, split_coordinate(Start), split_coordinate(End)};
80
+
["turn", "on", Start, _, End] -> {on, split_coordinate(Start), split_coordinate(End)};
81
+
["turn", "off", Start, _, End] -> {off, split_coordinate(Start), split_coordinate(End)}
82
+
end.
83
+
84
+
read_input() -> read_input("").
85
+
read_input(Prev) ->
86
+
case io:get_line("") of
87
+
eof -> Prev;
88
+
{error, _} -> halt(1);
89
+
Data when Prev == "" -> read_input([parse_line(Data)]);
90
+
Data -> read_input(Prev ++ [parse_line(Data)])
91
+
end.
92
+
93
+
main(Args) ->
94
+
Input = read_input(),
95
+
case Args of
96
+
["1"] ->
97
+
part1(Input);
98
+
["2"] ->
99
+
part2(Input);
100
+
_ ->
101
+
part1(Input),
102
+
part2(Input)
103
+
end.