Complete day 9 part 1
This commit is contained in:
parent
9f337f8a6d
commit
5717adcf1c
110
day9/src/main.rs
110
day9/src/main.rs
@ -11,7 +11,7 @@ use Direction::*;
|
||||
|
||||
struct Move {
|
||||
dir: Direction,
|
||||
amount: usize,
|
||||
amount: isize,
|
||||
}
|
||||
|
||||
impl Move {
|
||||
@ -25,7 +25,7 @@ impl Move {
|
||||
"R" => Right,
|
||||
_ => panic!("Invalid direction!"),
|
||||
};
|
||||
let amount = parts[1].parse::<usize>().unwrap();
|
||||
let amount = parts[1].parse::<isize>().unwrap();
|
||||
|
||||
Move { dir, amount }
|
||||
}
|
||||
@ -33,17 +33,23 @@ impl Move {
|
||||
|
||||
#[derive(Debug, Default, Copy, Clone, Eq, Hash, PartialEq)]
|
||||
struct Location {
|
||||
x: usize,
|
||||
y: usize,
|
||||
x: isize,
|
||||
y: isize,
|
||||
}
|
||||
|
||||
impl Location {
|
||||
fn new(x: usize, y: usize) -> Self {
|
||||
fn new(x: isize, y: isize) -> Self {
|
||||
Location { x, y }
|
||||
}
|
||||
|
||||
fn get_distance(self, other: Self) -> f64 {
|
||||
let squares = (other.x - self.x).pow(2) + (other.y - self.y).pow(2);
|
||||
|
||||
(squares as f64).sqrt()
|
||||
}
|
||||
}
|
||||
|
||||
// ----------------------------------------------------------------------------
|
||||
// ---------------------------------------------------------------------------
|
||||
|
||||
#[derive(Debug, Default)]
|
||||
struct Rope {
|
||||
@ -55,21 +61,31 @@ struct Rope {
|
||||
|
||||
impl Rope {
|
||||
pub fn new() -> Self {
|
||||
Rope { ..Rope::default() }
|
||||
let mut rope = Self::default();
|
||||
rope.head_visited.insert(Location::default());
|
||||
rope.tail_visited.insert(Location::default());
|
||||
|
||||
rope
|
||||
}
|
||||
|
||||
pub fn move_head(&mut self, moves: Move) {
|
||||
let from = self.head;
|
||||
|
||||
for _ in 0..moves.amount {
|
||||
let mut x = from.x;
|
||||
let mut y = from.y;
|
||||
let mut x = self.head.x;
|
||||
let mut y = self.head.y;
|
||||
|
||||
match moves.dir {
|
||||
Up => y += 1,
|
||||
Down => y -= 1,
|
||||
Left => x -= 1,
|
||||
Right => x += 1,
|
||||
Up => {
|
||||
y += 1;
|
||||
}
|
||||
Down => {
|
||||
y -= 1;
|
||||
}
|
||||
Left => {
|
||||
x -= 1;
|
||||
}
|
||||
Right => {
|
||||
x += 1;
|
||||
}
|
||||
}
|
||||
|
||||
let to = Location::new(x, y);
|
||||
@ -80,7 +96,42 @@ impl Rope {
|
||||
}
|
||||
}
|
||||
|
||||
fn move_tail(&mut self, head: Location) {}
|
||||
fn must_tail_move(&mut self, head: Location) -> bool {
|
||||
let distance = self.tail.get_distance(head);
|
||||
|
||||
distance >= 2.0
|
||||
}
|
||||
|
||||
fn move_tail(&mut self, head: Location) {
|
||||
if !self.must_tail_move(head) {
|
||||
return;
|
||||
}
|
||||
|
||||
let mut tail = self.tail.clone();
|
||||
|
||||
if tail.y != head.y {
|
||||
if head.y - tail.y < 0 {
|
||||
tail.y -= 1;
|
||||
} else {
|
||||
tail.y += 1;
|
||||
}
|
||||
}
|
||||
|
||||
if tail.x != head.x {
|
||||
if head.x - tail.x < 0 {
|
||||
tail.x -= 1;
|
||||
} else {
|
||||
tail.x += 1;
|
||||
}
|
||||
}
|
||||
|
||||
self.tail = tail;
|
||||
self.tail_visited.insert(tail);
|
||||
}
|
||||
|
||||
fn get_tail_pos_count(&self) -> usize {
|
||||
self.tail_visited.len()
|
||||
}
|
||||
}
|
||||
|
||||
// ----------------------------------------------------------------------------
|
||||
@ -93,6 +144,10 @@ fn main() {
|
||||
.lines()
|
||||
.map(Move::from_line)
|
||||
.for_each(|m| rope.move_head(m));
|
||||
|
||||
let tail_positions = rope.get_tail_pos_count();
|
||||
|
||||
println!("Part 1: Number of tail movements: {}", tail_positions);
|
||||
}
|
||||
|
||||
#[cfg(test)]
|
||||
@ -102,4 +157,27 @@ mod tests {
|
||||
fn get_data() -> &'static str {
|
||||
include_str!("test-input.txt")
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_location_get_distance() {
|
||||
let a = Location::new(0, 0);
|
||||
|
||||
assert_eq!(a.get_distance(Location::new(0, 0)), 0.0);
|
||||
assert_eq!(a.get_distance(Location::new(1, 0)), 1.0);
|
||||
assert_eq!(a.get_distance(Location::new(1, 1)), 2.0f64.sqrt());
|
||||
}
|
||||
|
||||
#[test]
|
||||
fn test_get_tail_position_count() {
|
||||
let mut rope = Rope::new();
|
||||
|
||||
assert_eq!(rope.get_tail_pos_count(), 1);
|
||||
|
||||
get_data()
|
||||
.lines()
|
||||
.map(Move::from_line)
|
||||
.for_each(|m| rope.move_head(m));
|
||||
|
||||
assert_eq!(rope.get_tail_pos_count(), 13);
|
||||
}
|
||||
}
|
||||
|
Reference in New Issue
Block a user