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|
use advent_of_code::prelude::*;
pub struct Map {
grid: Grid<u8>,
}
impl advent_of_code::graph::Graph<(Row, Col), (Row, Col)> for Map {
type Edges = advent_of_code::grid::Adjacent;
fn edges(&self, v: (Row, Col)) -> Self::Edges {
self.grid.adjacent(v.0, v.1, false)
}
fn edge(&self, _v: (Row, Col), e: (Row, Col)) -> ((Row, Col), u64) {
(e, u64::from(self.grid[e.0][e.1]))
}
}
pub fn parse(fh: File) -> Result<Map> {
Ok(Map {
grid: parse::digit_grid(parse::raw_lines(fh)),
})
}
pub fn part1(map: Map) -> Result<u64> {
Ok(map
.dijkstra(
(Row(0), Col(0)),
(map.grid.rows() - 1, map.grid.cols() - 1),
)
.0)
}
pub fn part2(map: Map) -> Result<u64> {
let mut large_grid = Grid::default();
large_grid.grow(Row(map.grid.rows().0 * 5), Col(map.grid.cols().0 * 5));
for lrow in 0..5 {
for lcol in 0..5 {
for ((Row(row), Col(col)), val) in map.grid.indexed_cells() {
let mut val = val + lrow + lcol;
while val > 9 {
val -= 9;
}
large_grid[Row(usize::from(lrow) * map.grid.rows().0 + row)]
[Col(usize::from(lcol) * map.grid.cols().0 + col)] = val;
}
}
}
let large_map = Map { grid: large_grid };
Ok(large_map
.dijkstra(
(Row(0), Col(0)),
(large_map.grid.rows() - 1, large_map.grid.cols() - 1),
)
.0)
}
#[test]
fn test() {
assert_eq!(
part1(parse(parse::data(2021, 15).unwrap()).unwrap()).unwrap(),
441
);
assert_eq!(
part2(parse(parse::data(2021, 15).unwrap()).unwrap()).unwrap(),
2849
);
}
|
