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//use std::{thread::{sleep}, time::Duration};
use std::{collections::VecDeque, thread::sleep, time::Duration};
const ROCK: char = '#';
const AIR: char = '.';
//type Grid = Vec<Vec<char>>;
type GridRow = (usize,Vec<char>);
struct Grid {
rows: VecDeque<GridRow>
}
impl Grid {
const WIDTH:usize = 7;
fn new() -> Grid {
let mut rows = VecDeque::new();
rows.push_back((0,(0..Grid::WIDTH).map(|_| { AIR }).collect()));
Grid { rows }
}
fn iy(&mut self, p: &Pos) -> usize {
let lb = self.rows[0].0;
let y = p.y as usize;
let iy:usize = y - lb; // will fail if we try to access a trimmed blcok
// Grow on demand
if iy >= self.rows.len() {
let lr = self.rows.back().unwrap().0;
for y in (lr+1)..=y {
self.rows.push_back((y, (0..Grid::WIDTH).map(|_| { AIR }).collect()))
}
}
iy
}
fn get(&mut self, p: &Pos)->char {
let iy = self.iy(p);
self.rows[iy].1[p.x as usize]
}
fn set(&mut self, p: &Pos, x: char) {
let iy:usize = self.iy(p);
self.rows[iy].1[p.x as usize] = x;
}
fn trim(&mut self) {
// cheat, jjust keep the top 100 rows
// really we should check for impassable points
// I don't really like this solution either tbh, I want an rtruncate method...
let tt = self.rows.len() as i32 - 30;
if tt > 0 {
for _ in 0..tt {
let _ = self.rows.pop_front();
}
}
}
fn rock_height(&self) -> usize {
self.rows.iter()
.rfind(|row| {
row.1.iter().any(|cell| {*cell == ROCK})
})
.map(|row| {
row.0+1 // height is one more than the index..
})
.unwrap_or(0)
}
fn print(&self, rock: &Rock, rock_count: usize) {
print!("{}[2J", 27 as char); // clear terminal!
println!("+++++++");
let pts = rock.points();
for (y ,row) in self.rows.iter().rev() {
print!("{:012} ", y);
for (x, cell) in row.iter().enumerate() {
if pts.contains(&Pos{x:(x as i32),y:(*y as i32)}) {
print!("@");
} else {
print!("{}", cell);
}
}
print!("\n");
}
println!("+++++++ height: {} rocks: {}", self.rock_height(), rock_count);
}
}
#[derive(Debug,Clone,PartialEq)]
struct Pos {
x: i32,
y: i32,
}
impl Pos {
fn new(x:i32,y:i32) -> Pos {
Pos{x, y}
}
fn translate(&self, other: &Pos) -> Pos {
Pos{x: self.x+other.x, y: self.y+other.y}
}
}
/*
####
.#.
###
.#.
..#
..#
###
#
#
#
#
##
##
*/
#[derive(Debug,Clone,PartialEq)]
enum RockType {
Bar,Cross,Ell,VBar,Square
}
impl RockType {
fn points(&self) -> Vec<Pos> {
match self {
Self::Bar => vec![Pos::new(0,0), Pos::new(1,0), Pos::new(2,0), Pos::new(3,0)],
Self::Cross => vec![Pos::new(1,0), Pos::new(0,1), Pos::new(1,1), Pos::new(2,1), Pos::new(1,2)],
Self::Ell => vec![Pos::new(0,0), Pos::new(1,0), Pos::new(2,0), Pos::new(2,1), Pos::new(2,2)],
Self::VBar => vec![Pos::new(0,0), Pos::new(0,1), Pos::new(0,2), Pos::new(0,3)],
Self::Square => vec![Pos::new(0,0), Pos::new(0,1), Pos::new(1,0), Pos::new(1,1)],
}
}
}
#[derive(Debug,Clone,PartialEq)]
enum Direction {
Down,Left,Right
}
impl Direction {
fn unit(&self)->Pos {
match self {
Self::Down => Pos{x:0, y:-1},
Self::Left => Pos{x:-1, y:0},
Self::Right => Pos{x:1, y:0},
}
}
}
#[derive(Debug,Clone,PartialEq)]
struct Rock {
rtype: RockType,
pos: Pos, // Position of lower left point in formation
}
impl Rock {
fn points(&self) -> Vec<Pos> {
self.rtype.points()
.into_iter().map(|p| {p.translate(&self.pos)}).collect()
}
pub fn mv(self, dir: Direction, grid: &mut Grid) -> Result<Self,Self> {
let du = dir.unit();
let np: Vec<Pos> = self.points().into_iter().map(|p| {p.translate(&du)}).collect();
if np.iter().any(|p| {
// Bounds check
p.y < 0 ||
p.x < 0 ||
p.x >= Grid::WIDTH as i32 ||
// Intersecting another rock?
grid.get(p) != AIR
}) {
Err(self)
} else {
let mut nr = self.clone();
nr.pos = self.pos.translate(&du);
Ok(nr)
}
}
pub fn solidify(self, grid: &mut Grid) {
for pt in self.points() {
grid.set(&pt,ROCK);
}
}
}
pub fn run(input: String) {
let mut rocks = vec![RockType::Bar,RockType::Cross,RockType::Ell,RockType::VBar,RockType::Square].into_iter().cycle();
let mut gas_jets = input.chars().cycle();
let mut grid: Grid = Grid::new();
let mut rock = Rock{
rtype: rocks.next().unwrap(),
pos: Pos{x: 2, y: 3}
};
let mut rock_count: usize = 1;
'lp: loop {
let push = match gas_jets.next().unwrap() {
'>' => Direction::Right,
'<' => Direction::Left,
dir => panic!("Unexpected jet direction! {}", dir)
};
// apply jet, ignore any error.
rock = rock.mv(push, &mut grid).unwrap_or_else(|e| {e});
// apply gravity
rock = match rock.mv(Direction::Down, &mut grid) {
Ok(rr) => rr, // Complete the move!
Err(rr) => {
// We didn't move, solidify!
rr.solidify(&mut grid);
if rock_count == 1_000_000_000_000 {
break 'lp;
}
// Measure height...
let max_rock = grid.rock_height();
// remember how many rocks we did
rock_count += 1;
if rock_count % 1_000_000 == 0 {
println!("Done {} rocks...", rock_count);
}
// Spawn new rock
Rock {
rtype: rocks.next().unwrap(),
pos: Pos{x: 2, y: max_rock as i32 +3 }
}
}
};
grid.trim();
// grid.print(&rock, rock_count);
//print(&grid, &rock, rocks_count);
// sleep(Duration::from_millis(50));
// It just isn't enough.. we need to detect the repeating pattern!!!!! or find a fast enough computer :D
}
println!("Day 17: {}", grid.rock_height());
}
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