106 lines
2.0 KiB
Rust
106 lines
2.0 KiB
Rust
use std::collections::HashSet;
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#[derive(Debug)]
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enum Direction {
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Up,
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Down,
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Left,
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Right,
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}
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use Direction::*;
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struct Move {
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dir: Direction,
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amount: usize,
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}
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impl Move {
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fn from_line(line: &str) -> Self {
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let parts: Vec<&str> = line.split_ascii_whitespace().collect();
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let dir = match parts[0] {
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"U" => Up,
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"D" => Down,
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"L" => Left,
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"R" => Right,
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_ => panic!("Invalid direction!"),
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};
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let amount = parts[1].parse::<usize>().unwrap();
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Move { dir, amount }
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}
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}
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#[derive(Debug, Default, Copy, Clone, Eq, Hash, PartialEq)]
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struct Location {
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x: usize,
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y: usize,
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}
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impl Location {
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fn new(x: usize, y: usize) -> Self {
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Location { x, y }
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}
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}
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// ----------------------------------------------------------------------------
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#[derive(Debug, Default)]
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struct Rope {
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head: Location,
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tail: Location,
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head_visited: HashSet<Location>,
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tail_visited: HashSet<Location>,
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}
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impl Rope {
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pub fn new() -> Self {
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Rope { ..Rope::default() }
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}
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pub fn move_head(&mut self, moves: Move) {
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let from = self.head;
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for _ in 0..moves.amount {
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let mut x = from.x;
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let mut y = from.y;
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match moves.dir {
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Up => y += 1,
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Down => y -= 1,
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Left => x -= 1,
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Right => x += 1,
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}
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let to = Location::new(x, y);
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self.move_tail(to);
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self.head = to;
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self.head_visited.insert(to);
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}
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}
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fn move_tail(&mut self, head: Location) {}
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}
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// ----------------------------------------------------------------------------
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fn main() {
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let file_str = include_str!("input.txt");
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let mut rope = Rope::new();
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file_str
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.lines()
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.map(Move::from_line)
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.for_each(|m| rope.move_head(m));
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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fn get_data() -> &'static str {
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include_str!("test-input.txt")
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}
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}
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