83 lines
1.6 KiB
Rust
83 lines
1.6 KiB
Rust
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#[derive(Copy, Clone, PartialEq)]
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struct Pos {
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x :i32,
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y :i32
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}
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fn move_tail(head :&Pos, tail :&mut Pos) {
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let dx = head.x - tail.x;
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let dy = head.y - tail.y;
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if dx.abs() > 1 || dy.abs() > 1{
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tail.x += dx.signum();
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tail.y += dy.signum();
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}
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}
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fn execute_move(head :&mut Pos, tails :&mut Vec<Pos>, cmd :&char) {
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match cmd {
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'U' => {
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head.y += 1;
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}
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'D' => {
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head.y -= 1;
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}
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'L' => {
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head.x -= 1;
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}
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'R' => {
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head.x += 1;
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}
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_ => {}
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}
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move_tail(head, &mut tails.first_mut().unwrap());
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for i in 1..tails.len() {
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move_tail(&tails[i-1].clone(), &mut tails[i]);
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}
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}
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fn parse_command(inp :&String) -> (char, i32) {
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let split = inp.split(' ').collect::<Vec<&str>>();
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return (split[0].chars().nth(0).unwrap(), split[1].parse::<i32>().unwrap());
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}
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pub fn run(inp :Vec<String>) {
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let mut visited_coordinates :Vec<Pos> = vec![];
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let mut head_pos = Pos {x: 0, y: 0} ;
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let mut tails :Vec<Pos> = vec![Pos {x: 0, y: 0}; 9];
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visited_coordinates.push(head_pos.clone());
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for curr_move in inp {
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let commands = parse_command(&curr_move);
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for _ in 0..commands.1 {
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execute_move(&mut head_pos, &mut tails, &commands.0);
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if !visited_coordinates.contains(&tails.last().unwrap()) {
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visited_coordinates.push(tails.last().unwrap().clone());
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}
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}
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}
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println!("a2: {}", visited_coordinates.len());
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}
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