advent-of-code-2024/day14/part2.rs
2024-12-15 21:12:26 -07:00

57 lines
1.6 KiB
Rust

const INPUT: &str = include_str!("input.txt");
const GRID_WIDTH: i64 = 101;
const GRID_HEIGHT: i64 = 103;
const SQUARE_THRESHOLD: i64 = 4; // 4x4 square
#[derive(Debug)]
pub struct Robot {
pub position: (i64, i64),
pub velocity: (i64, i64),
}
fn main() {
let mut robots = INPUT
.lines()
.map(|l| l.split_once(" v=").unwrap())
.map(|(p, v)| {
(
p.trim_start_matches("p=").split_once(",").unwrap(),
v.split_once(",").unwrap(),
)
})
.map(|(p, v)| Robot {
position: (p.0.parse().unwrap(), p.1.parse().unwrap()),
velocity: (v.0.parse().unwrap(), v.1.parse().unwrap()),
})
.collect::<Vec<_>>();
let mut i = 0u64;
loop {
i += 1;
for robot in robots.iter_mut() {
robot.position = (
((robot.position.0 + robot.velocity.0)).rem_euclid(GRID_WIDTH),
((robot.position.1 + robot.velocity.1)).rem_euclid(GRID_HEIGHT),
);
}
// Check for square
let square = robots.iter().map(|r| r.position).any(
|(start_x, start_y)|
(start_x..(start_x + SQUARE_THRESHOLD)).all(
|x|
(start_y..(start_y + SQUARE_THRESHOLD)).all(
|y|
robots.iter().any(
|r|
r.position == (x, y)
)
)
)
);
if square { break; }
}
println!("Result: {}", i);
}