1use crate::util::grid::*;
5use crate::util::hash::*;
6use crate::util::point::*;
7
8type Input = (Grid<u8>, FastMap<u8, Vec<Point>>);
9
10pub fn parse(input: &str) -> Input {
11 let grid = Grid::parse(input);
12 let mut antennas = FastMap::new();
13
14 for y in 0..grid.height {
15 for x in 0..grid.width {
16 let point = Point::new(x, y);
17 let frequency = grid[point];
18
19 if frequency != b'.' {
20 antennas.entry(frequency).or_insert_with(Vec::new).push(point);
21 }
22 }
23 }
24
25 (grid, antennas)
26}
27
28pub fn part1(input: &Input) -> u32 {
29 let (grid, antennas) = input;
30 let mut locations = grid.same_size_with(0);
31
32 for frequency in antennas.values() {
33 for &first in frequency {
34 for &second in frequency {
35 if first != second {
36 let distance = second - first;
37 let antinode = second + distance;
38
39 if grid.contains(antinode) {
40 locations[antinode] = 1;
41 }
42 }
43 }
44 }
45 }
46
47 locations.bytes.iter().sum()
48}
49
50pub fn part2(input: &Input) -> u32 {
51 let (grid, antennas) = input;
52 let mut locations = grid.same_size_with(0);
53
54 for frequency in antennas.values() {
55 for &first in frequency {
56 for &second in frequency {
57 if first != second {
58 let distance = second - first;
59 let mut antinode = second;
60
61 while grid.contains(antinode) {
62 locations[antinode] = 1;
63 antinode += distance;
64 }
65 }
66 }
67 }
68 }
69
70 locations.bytes.iter().sum()
71}