day 17

7 files changed, 321 insertions, 23 deletions

diff --git a/benches/2022.rs b/benches/2022.rs
index f6ebbc1..274ee25 100644
--- a/benches/2022.rs
+++ b/benches/2022.rs
@@ -33,6 +33,8 @@ mod day14;
 mod day15;
 #[path = "../src/bin/2022/day16.rs"]
 mod day16;
+#[path = "../src/bin/2022/day17.rs"]
+mod day17;
 // NEXT MOD
 
 day!(2022, 1, day1);
@@ -51,6 +53,7 @@ day!(2022, 13, day13);
 day!(2022, 14, day14);
 day!(2022, 15, day15);
 day!(2022, 16, day16);
+day!(2022, 17, day17);
 // NEXT DAY
 
 fn bench_2022(c: &mut criterion::Criterion) {
@@ -72,6 +75,7 @@ fn bench_2022(c: &mut criterion::Criterion) {
             day_combined!(2022, 14, day14);
             day_combined!(2022, 15, day15);
             day_combined!(2022, 16, day16);
+            day_combined!(2022, 17, day17);
             // NEXT DAY COMBINED
         })
     });
@@ -96,5 +100,6 @@ criterion::criterion_main!(
     bench_2022day14,
     bench_2022day15,
     bench_2022day16,
+    bench_2022day17,
     // NEXT GROUP
 );
diff --git a/data/2022/17.txt b/data/2022/17.txt
new file mode 100644
index 0000000..7283833
--- /dev/null
+++ b/data/2022/17.txt
@@ -0,0 +1 @@
+>>><<<<>><<<<>>>><<><<<<>><><<<><<<<>>><<<<><<>>>><<<<>><<<<>><<<>><>><<<>><>><<>>><<>><<<>>><<<<>>><<<<>>><<<<><<<<><>>><<<>>>><<>><<<><<<<><<<>>><<<<>>>><<<><<<><>>><<><>><<<<>>><>>>><<>>>><<<<><<<<><<<<>>><<>><><<<>><<<><<>>><<>>><>><>>><>>>><<<<>><<>>><<<>><<><<>><<<<>>><>><><>>>><<<<><>><<>><>>>><<>>><<>>><<>>><><<<<>>><<<>>><><<>>>><<<>><<<>>>><<>><<<>><<<>>>><>>>><<>><<<<>><<<>>><<>>><<>><<<>>>><<>><<<>><>>>><>><<<>>>><><<>>><<>>>><>><><<<<>>><<>><<>><<<<>><>>>><<<<>>>><<<>>><<<<>><<<<>>><<<<>>><<>>>><<>><>>><<><<<>>>><<<<>><<>><><<<<>>>><<<<><<<>><><<<><<>><>><<<<>><<><<<>><>><>><>>>><<<><>>><>>>><<<<>>><<<>>>><>>><>>><<<><<<>>><<<<>>><<><<<<>>>><<<<><<>>>><<>><<<<>>>><>>>><<>><<>><<><>>>><><><<<<>>><<<>>><<<<>>>><<>>><<<<>>>><><<><<<<>>><<<<>>>><<<>><>><<<<>>>><><>>>><>>><<><<<<>><<<<>>>><<>>><<>>>><>>><<>>><><<<<>>><<<>><>>>><<<><<<<>>>><<<<>><>><<>>>><<><>><>>><<>>>><<<<>>><<<<>>><<<>><<>><<>>><>><>><<<<>><<<>><><<<>><<<>>>><<<<><<<<>>><><<<><<>>><<<>>><<<<>>><<>>><<<><<>>><<<>>>><<<<>>><>>>><<>><>><<<<>><<<<>>>><<>><<<<><>><<<<>>>><>>><<<<>>><>><<<<><<<><<<>><><<<>>>><><<<>><>>><<<<>>>><<<<>>>><<>><<<<>><<<><<>>>><<<>>><<<><<><<<<>>>><<><<>><<>>>><<<<><><<<<>>>><<<<>><>>><<<>>><<<>><<<>><<>><<<<>>><<<<>>>><<<><>>>><<>><<>>>><<<><>>><><><<<>><<><<<><<<<>>>><<<>>><<<>>><<<<><><<<>>><<<<>>>><<>>>><<>><<>>><>>><<<>><<<<>>><<<<>><<<<>>><<><<<>>><<<>><<><<><<<<>>>><>>>><<>>><<<<>>>><<<<>><<<>><<<<>>>><<<>>>><<><<<><<<>>>><<<<>>><<<<>><<>>>><>><><<<>>><<<>>>><<<<>><<>>><><>><<<>>><<<>>>><<>>>><<<<><><>>>><<>><<<>><<<<>>><<<>>><<<>>><<<>>>><<>>><<>>>><><><>><<<<>>><<<<>>>><<<><><<<<><<>><<<<>><<><<<><<<>><<><<<>>>><>><><>><<<>>><<<<>>>><<<<>><<>><><<<>>><>>>><>>><<<<>>><><<<><>>>><<<><<>><<<>><>>><><<<<>><<>>>><<>>><<<>>><<<<>><>>><>>><<<>>>><<>>><><<<><<<>>><<<>>><<<<>>>><<<>><>>>><<<<>>>><<<>>>><<>>>><<<><<<<>><<<<><<><<>>>><<<<>><><>>><<>>>><>>><<<<>>><<<<>><<<><<<>>><<><<>>><<>><<<>>>><>>><<<<>>><<<>>><>>>><<<<>>><<<<>>><><<<<>>><><<<><<<>>>><<><<>><><<<<>>>><<<<>><<>>>><<><<<<>>>><<<<>>>><>>><<<>>>><<<<><>><<><<<>>><<<<><<<<>>>><>><>>><<<>>>><><<<<><<<<>><<<>><<<<><<<>>><><<<<>><<>><<<>><<<>>><<><<<>>><<><><<<<>>>><<>><<<><>>>><>>>><<>>><>><><<<>>><>>>><><<<<><>>><<>>>><<>><<>>>><<<>>>><<<<>>>><<<>><<<<>><<><<<>>><>>><<<>>><<<<>><<>>>><>>><<>>><<<>>><>><>>><<>><<<<>>><>><<>>>><<<<><<<<>>><<<><><><>>><<>>><<<<>>>><<<<>><>><<<<>>><<>><>>><<<>>>><<<<>>>><><><<<>>>><><<<>>><<<<>>>><<>>>><<<>>>><<><<<>>><<<<>>><<>>>><><>>><><>>><<<<>>>><<<>><<>>>><<><<>>><>><><>>><<<<>>><<>>><<<<>>><<<>>><>><<>>><<<>><>>>><<<>>><>>><<<>>>><<<<>>>><<<<><<<>>>><<<>>><<>>>><<<<><<<<>>><<<>><<<><<<>>><<<<>><<>><<<>>>><>>>><<<<><<<<>><<>><<>><<<><<<<>><<<>><<<<>>>><>>>><>><><<>>>><<<<>><<>>>><>>><<>>><<<<>>><<<>>><<<>>>><<>>>><>>>><><>><<<>><<<<><<<<>>>><<<>>>><>>><<<><<>>>><<<>>><>>>><<><<<><<<<>><<>>>><<<>><<<<><<><>>><>><>><>>>><<<>>><<>><<<<>>><<<>><<<<>>>><><<><<<>>>><<>>><<<><<><<<><<<<><>>><>><<<><<<>><<<><<>><<<<>>><<>>><<>>><<<<><>><<><<<<>><<<<>><<<<><>>><<<<>><<>>>><>><>>>><<<<>>><<<<>><><<<>><<>>>><>>>><<>>><><<>>>><<><<>><<<>><>>>><<<<>><<<><<><<>><<<>><<<>><>><>>>><<<<>>><<<<>>><<<>>>><>><<<>>>><<<<><>>><>>>><<>><<<<>><<<<>>><<<<>>><<<<><<<>>>><>>>><<<>>><<<>>>><<<>>>><<<<>>><<<<>>><<<><>>><<<<>>>><<<<><>>>><<>><<<>>>><<><<<<><>><><<>>><<<<>>><<<<>>>><<<<>>>><<>><<<<>>><<<<>>>><<>>>><<<>>><<<<>>>><<<><<<<><<>><<<<>>><<<<>>><>>>><>><<<<><<<>>><>>>><><<<><<<>><>>><<>><>><<<><>>><<><<<>>><>>><<<<><>>><<><<><<<<><<<>>><<<<>>><>>>><>><<<<>><<>><<<<>>><<<>><>><<<><>>>><>><<><><>>>><<<<><>>><<><<<<>><<<<><>>>><<>>><<<>><<<>>>><<>>><>>>><<<>>>><<>>><<<>>>><<<>><>>>><<><>>>><>>><>>>><<<>>>><<<<>>>><<>>><<>>><<<<>>>><>>>><<><>><<<<>>><><<<><<<<>>>><<<<>>>><<>>><<<>><<<>><<<>>>><<<<>>>><<<<>><<>>><<><<>>>><>><>><>>><<>><<<>>><<<<>><<>><<<<>>><>>>><<<<><<<>>>><>>><<>><>>>><>>>><><<<<>><<<><<<<>>>><<<>>><<<<>>>><<<<>>><<<>>><>>><<<>>>><>>>><<<<>>><<<<><<><<<<><<<<><>>>><<><>>>><<>><<<>><>>><<<<>><>><<<><<>>>><<>>>><>>><<<><<<>><>>><><<>>><<><<>>><<<>>>><<<<>><<><<<<>>>><<<<>>>><<<<><<<<>>><<<<><<<><>>><<>>>><<>>>><<<<>>><<<>>><<<>>>><<<<>>><>>><<>>>><<<<>>>><<<>><<<>>>><<<>><><<<>><><<<>>><><<<><>>>><<>><<<<>>>><<<>>>><<>>><<<<><<<<>>>><<>>><<<<>>>><>>><<<>>><<<<>>>><<>>><<>>><<>>><<<>><<><<>><><>><>>>><<<<>>><<<<>>>><<<><<>>><<<><<<>>>><<<<>>><<<<>>><<<<>><<<<>>><<<<>>><<<><<<><<<<><<>>><><<<>>><<>>>><<>>><>>>><<<>>>><<<<>>><>>>><<>><<<>>><<<>><>><<><>>><<<><<<<>>>><<>><<<>><>>>><<<>><<>><<>>>><><>><>>>><<<><<<<><><>>>><<>>>><<<>>><><<>><<<<><<<<>>><>>><<>><<<>>>><<<<>>>><><<<<>><<<<>><<><<>>>><<><<<<><>>>><<>><<<>><>><<<<><>>>><>><<>><<>>>><<<<>>><<<<>>>><<>>>><<<<>>><<<>>><><<<>>>><><>>><<<><<><<<<><<<>>><<>>><<>>>><<<><<<<>>>><<<>>>><<><<<<>>>><<<<>>><<<>>><<>>><><>>><<<<>>>><<><<<>>>><<<<><<><><<><<<<>><<<><<<<>><<>><<>>><>><>><<<<>>>><>>><><<>>>><<<>>><<<<>>>><<<<><>>>><<<>><>>><<<<>>>><<><<>>><<><>>><<>><<<<>><<<>><<>><<<><<>>>><<>><>>><>>><<<>><<<<>><<<><<>><<<<>>>><<<<>>><><<<<>>>><<><>>><<<>>>><<><>>>><<<<>><>><<<>><<>><<<<>>>><<<>>>><<<>><>>>><>>>><>>>><<<<>>>><<>>>><<<><<>>>><<><<<><<<>>>><<<<>>>><<<<>><>>>><>>><<><<<><>><<>>><>>>><<>>>><<<<>>>><>>><>><<>><<<>><<<><><<<<>>><<<<><<>>>><>>><<>><<>><<<<><<<<><<<>><<<<>>>><<><<<><<<<>>><<<>>>><<<<>><>><<<><><<<<>><<<<>><>>>><<<<>>><>>>><>><<>>>><<<>>><<>>><>>>><>><>>><>>><<><<>>><<>><<<>><<<>><<<>>><><>>><>>>><<>>>><<<<>><>>>><>>>><>><<>>><<<<>>>><<>><><<>>><<<>>><<<>>>><<><<<<><>>>><>>><<<>>><<<><<<<>>><>>>><<>>><<>>>><><<>><<>>><>>><>>><<><<<><>><<<>>><>><<<><<>>>><<<>>><<<<>><<>>>><>>>><<<<>>><<<<><<<<>><<<><<>>>><><<<<>><<<><<<>>>><<<>><<<<>>><<<><<<>>>><<><>>><<<>><<<<><<<>>><<<>><>><<<>>>><>>><<><<>>><<<>>>><<<<>>><<<<>>><<<<><><><<>>><<>><<<>>>><<<>>>><><<<>>>><>>><<>><<>><>>><><<>><<<<>><<<<>>><<><<>>><<>>><<><<<<><<<>><><<>>>><<<<>>><<<>>><<<<><<<<><<>><<<><<>>>><>>><<<>>>><<<>>>><>>><>><<>><<>>><<>><<<<>><<>><<<>>><<<<><>>><>><<<><<>><<<<><<<><<>><<>>>><>>>><<><<><<>><>>>><><><<<<>>><><<>>>><<<><<<<>><<<<>><><<<><>>>><<<>>>><<>><<<>>><<>>>><<<<>>>><><<<>>><<<<><<<><<<><<<<>>>><>><<<<>>>><>>>><<<<>>><>>>><<<<>><<<>>>><<<<>>>><<>>>><<>><<<<>><<<><<<<>>><>><<<<>><>>><<<>>><<<<>>>><>><<><<>><><<<<>>>><<<<>><>>>><<<>>>><<>>>><>>>><<><>>>><<<<>>>><<<<>><<<<>>><><<><<<><<<<>>><>><<>>><<>>>><<<>>>><<>>><<<>>>><<><>>>><<<><><<<><<<>><<<><<<<>>><<><<<<>><>>><>>><>>><><>><<>>><<<<>>><>>><<<<><<<>>>><<>><<<<>>>><<<>><><<<<><<<<>>>><<>><<>>>><<>>>><><<<<>>><>>><<>><<<<>>>><>>>><<<<>><<>>><<<>>><>>>><<<>>>><<<><<><<><<<>>>><>>><<<>><<<>><<<<>>>><<<>><<<<>>><<>>><<<>>>><><<>>>><<<>>><<<>>>><<<<>><<>>><<<<>><<>>><>>><<<<><>>>><<<><>>>><<<<>><<<<><>>>><<<<>><>><<<<><<>>><<<<>>><><<<<><>>>><<<<><<<<>><<<<>>><<>>><<<<><>>>><<>>>><><<<>>>><>><<<>>><<<<><<>>>><<<<>>><><>>><>><<<>><<<<>>>><>>>><<<<>>><<<<>>><<>><<<>>>><<<>>><<>><>><><><<<><><<<>>><<<<>><<<<>><>>>><<>><><<>><<<<>>>><>><>>><>>><<<>>><<><>><><<<><<>>>><<<<>>>><>>><<<<>><<<>>><><<<<><<<>><<><<<><<>>><<<>>><<<>>>><><<>>><<<<><<<>>>><<>>><>><<<<>>>><<<<>>>><<>>><<>>>><<<<>><<<<>>>><<<<>><<>><>>><<>>><<>>>><<>>>><<<>>>><<<<>>>><<<><<<>>>><<<<>>>><<>>>><<<<>>>><<<><><>>><<>><<<<>>><<<<>>><><<><<<<><<><<<<>>><>>><<<<>>><<<<>><<<<>>>><<><<>><<>><<<<>>>><<<<>><><<>><>>>><>><><>>>><<<><<>>><<>>>><<><<<<><<>><>>>><>>>><<<<>>>><<<>>><<>><<<><<<>>><<>><<<><>>>><>>>><<>><>>>><<>><<<<>><>>><<>><<>>><<<<>>><<<><<<<>>><<<<>>><<<>><<>>><<<<>>><><<<<>>><<<<>>>><<<<>>>><><<>>>><<>>>><<<<>>>><>>><<<<><<>><<<>>><<<<>>>><>>><<<><<>>>><<<<>><<<><>>>><<<<>>><<<>>>><>>><<><>>>><<<<><<<<>>><<<>><<<><<<>>>><>>>><<<<><<>><<<><<>>>><<<>>>><>><<>>><<<><<<>><>>>><<>><<>>>><<<<><<<>><<<<><<>>><>><<<>>><<>><<><<<>>>><<<<>>><><<<<>><<>>>><<<<>>><>><<>><<>>>><<<><<>>>><<>>><<<>>><<<<><<<>><<<<>>><<>>><<<>><<<><<<<>>>><<<><<>><<<>><<>>><>>>><<<>>>><<>><<>>>><<>><<<<><>>>><<<>>>><<>>>><<<>><<<<><<<<>><<<<>>><<<<><<<<><<<><<<<>><<<<>>>><<<<>>><<<<>>><>><><><<>>><<>><<<<>><>>>><>><<<>>><>><>>><<<><<<><>>>><<><>><<>><><<>><<><<<>><<<>>><<>><<<><><<>><<<>><<<><<<>><>>><<<>>><<<>>><>>>><>>>><<<><>><<>><<<<><<<<>><<<<>><<<>>><<<>><<><<><<>><<><<><>>>><<<><<><<>>><<<>><<<>><<>>><<<<><<<<>>><<<<>><<><>><<>><<><<<><<<>>><<>>>><>><<<<><<<<>>>><<<<>>><>>><<>>>><<>>>><<>>><<<>><<<><<<<><<<<><<<<>>><<<>>>><<<<>><>><<<>>><<>>><<<<><>>>><<>>><<<<>>><<>><><<>>>><><<<>><>>><<><<<>>>><<<>>><<<><<<>>><>><<<><<<<>><<<<><<><<>>>><><<<<>>>><>><<>><<><<<><<<<>>><><<><<<<>>>><><<<<>>>><<>><<<>>>><>>>><<<<>>><<>>><><<<<>>>><><>>><<>><<<<>>><<<<><<<<><><<<<>>><<<<>>>><<><<>>>><<<>>><<>>><<><<<<><<>><>>><<<>>>><<<><<<<>>><<<>>>><<<<>><<<<>><<<<>><<<<><<<<>>>><<<<>>>><<<>>><<<>>><<<<>><><<<<>><>>>><<<<><>>>><<<<>><<>>><>><<<><<<<>>>><><<<><<>>>><<<<><<<><>>><<><>>>><<<<><<>>><<>>><<>>><<<>>><>>>><<<>>>><><<<<>>><<<<>>><<<<>>>><<<>>>><<>>><<>>>><<<<><>>>><>><<<<>>><<<<>>>><<<>>><<<>><<<>><<<>><>><>>>><>><<>><<<<><>>><<<<>>><>>><>>>><<<<>>><>>>><<><<<>>><>>><<<<>><<<>><<<<>><<<>>>><>>>><<<>>><<<<>>>><<<<>>>><<<>>>><><<<><<<>>>><<<><<<<>>>><<<>>>><>>><<<<><<<>><<<><<>><<>><<<<><<>>>><<<>>>><<<<>><>><>>>><>><<<><<><<<>>><<<<>>><<>><<<<>><><>><>><<>><>>>><<>>>><<>>><<<><>>><<<>>>><>><>>>><<<<><<>>><<<>>><<>>><>><><<<<>><><>>>><>><<<>><<<><<><>>><<<<><<<<>>><<>>>><<><<<<>>><<<>><<<<>>><<>>>><<>>>><<>><<<<>><<><<<><<<<>>>><><<>>><<<>>>><>>>><<><<<<>>>><<<>><>>><<<<>><<<<>>><<<><>>><<<>>><>>><<<<>><>>>><<<<>>><<><<<<>><<><<<<><<>><<<>>>><<<>><<<>>><<<>>>><<<<><<<>><<>>>><<>>>><>><<<<>>>><>>><<<><<>>><<<><<>>>><<<>>><<<>>><>><<<>>><<<<>><<>>>><<>>><<>>><<<>>><><<<>>><<>>>><>>><<>>><<>><<<><>>>><<>>>><<<<>><<>>><<<<>><<>><<>><<<>><<><>>><><<<>>>><><<>>><<>>><<<>>><<><><<<<>>><<<<><<>>>><<>><<<>>><<<>>>><>>><<<>>><<<<><<<>>><<<>><>><<><<<<>>><<>>>><<>><><<<<>>><<<<>>><<<<>>><<>><<>><<>><>><<<><>>><><>>>><<<>>><>>><<>>><<<><<>>>><<<><<<<>>><<<><<<><<<<>><<<<>><>>>><<<>>><<<><<<<>><<<<>><><<<<><<<<><<<>><<<>>>><>><<<>>><<>>><>><<<<>><<<><><<<<>>>><<<<>><<<>>>><<<<><<<>>>><<<<>>><<<>>><<>>>><>>>><<<<>><<<<>><<><<>><>>>><<>>>><<>><>>><<>>>><><<><>>><<><<<<>>>><<>>><<<<>><>>><<<<>><<<>><>>>><<<><<><<<>>><>>>><>>><<<>>><<>>><<<<><<<>>><>>><><<<>><<<>>><<<<>><<>>><<<<><>><>><><>>><<>><<
diff --git a/src/bin/2021/day25.rs b/src/bin/2021/day25.rs
index 4bd5c92..135f6b3 100644
--- a/src/bin/2021/day25.rs
+++ b/src/bin/2021/day25.rs
@@ -1,6 +1,6 @@
 use advent_of_code::prelude::*;
 
-#[derive(Debug, Clone, Eq, PartialEq)]
+#[derive(Debug, Clone, Eq, PartialEq, Hash)]
 pub enum Cell {
     Down,
     Right,
diff --git a/src/bin/2022/day17.rs b/src/bin/2022/day17.rs
new file mode 100644
index 0000000..46900e1
--- /dev/null
+++ b/src/bin/2022/day17.rs
@@ -0,0 +1,263 @@
+#![allow(dead_code)]
+#![allow(unused_variables)]
+
+use advent_of_code::prelude::*;
+
+#[derive(Clone, Copy, Debug)]
+pub enum Direction {
+    Left,
+    Right,
+}
+
+impl TryFrom<u8> for Direction {
+    type Error = Error;
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
+        match value {
+            b'<' => Ok(Self::Left),
+            b'>' => Ok(Self::Right),
+            _ => Err(anyhow!("unknown char {}", value)),
+        }
+    }
+}
+
+struct Piece(Vec<(Row, Col)>);
+static PIECES: once_cell::sync::Lazy<[Piece; 5]> =
+    once_cell::sync::Lazy::new(|| {
+        fn p(row: usize, col: usize) -> (Row, Col) {
+            (Row(row), Col(col))
+        }
+        [
+            Piece(vec![p(0, 0), p(0, 1), p(0, 2), p(0, 3)]),
+            Piece(vec![p(0, 1), p(1, 0), p(1, 1), p(1, 2), p(2, 1)]),
+            Piece(vec![p(0, 0), p(0, 1), p(0, 2), p(1, 2), p(2, 2)]),
+            Piece(vec![p(0, 0), p(1, 0), p(2, 0), p(3, 0)]),
+            Piece(vec![p(0, 0), p(0, 1), p(1, 0), p(1, 1)]),
+        ]
+    });
+
+#[derive(Default)]
+struct Chamber {
+    grid: Grid<bool>,
+    piece_pos: Option<(Row, Col)>,
+    piece_idx: usize,
+    extra_height: usize,
+    seen: HashMap<u64, usize>,
+    heights: Vec<usize>,
+}
+
+impl std::fmt::Display for Chamber {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let absolute_pos = if let Some(piece_pos) = self.piece_pos {
+            self.piece()
+                .0
+                .iter()
+                .map(|(row, col)| {
+                    (*row + piece_pos.0 .0, *col + piece_pos.1 .0)
+                })
+                .collect()
+        } else {
+            vec![]
+        };
+        for row in self
+            .grid
+            .each_row()
+            .take(
+                absolute_pos
+                    .iter()
+                    .copied()
+                    .map(|(row, _)| row.0)
+                    .chain(std::iter::once(self.height()))
+                    .max()
+                    .unwrap_or(0)
+                    + 1,
+            )
+            .rev()
+        {
+            write!(f, "|")?;
+            for col in self.grid.each_col() {
+                if absolute_pos.iter().any(|(piece_row, piece_col)| {
+                    row == *piece_row && col == *piece_col
+                }) {
+                    write!(f, "@")?;
+                } else if self.grid[row][col] {
+                    write!(f, "#")?;
+                } else {
+                    write!(f, ".")?;
+                }
+            }
+            writeln!(f, "|")?;
+        }
+        write!(f, "|-------|")?;
+        Ok(())
+    }
+}
+
+impl Chamber {
+    fn step(
+        &mut self,
+        idx: usize,
+        direction: Direction,
+    ) -> Option<(usize, Option<usize>)> {
+        if self.piece_pos.is_none() {
+            let pos = (Row(self.height() + 3), Col(2));
+            self.grid.grow(pos.0 + 4, Col(7));
+            self.piece_pos = Some(pos);
+        }
+        let (mut row, mut col) = self.piece_pos.unwrap();
+
+        // println!("{}/{:?}", self.height(), direction);
+        // println!("{}", self);
+        // println!("*********");
+        let new_col = Col(match direction {
+            Direction::Left => col.0.saturating_sub(1),
+            Direction::Right => col.0.saturating_add(1),
+        });
+        let piece = self.piece();
+        if !self.collides(piece, (row, new_col)) {
+            col = new_col;
+            self.piece_pos = Some((row, col))
+        }
+
+        // println!("{}/Down", self.height());
+        // println!("{}", self);
+        // println!("*********");
+        let collides = if row > Row(0) {
+            self.collides(piece, (row - 1, col))
+        } else {
+            true
+        };
+        if collides {
+            self.apply(piece, (row, col));
+            self.shrink();
+            self.heights.push(self.height() + self.extra_height);
+            let prev = self.seen_grid_hash(idx);
+            self.piece_pos = None;
+            self.piece_idx += 1;
+            Some((self.piece_idx - 1, prev))
+        } else {
+            row = row - 1;
+            self.piece_pos = Some((row, col));
+            None
+        }
+    }
+
+    fn piece(&self) -> &'static Piece {
+        &PIECES[self.piece_idx % PIECES.len()]
+    }
+
+    fn collides(&self, piece: &Piece, piece_pos: (Row, Col)) -> bool {
+        for pos in &piece.0 {
+            let absolute_pos =
+                (piece_pos.0 + pos.0 .0, piece_pos.1 + pos.1 .0);
+            if absolute_pos.1 >= Col(7) {
+                return true;
+            }
+            if self.grid[absolute_pos.0][absolute_pos.1] {
+                return true;
+            }
+        }
+        false
+    }
+
+    fn apply(&mut self, piece: &Piece, piece_pos: (Row, Col)) {
+        for pos in &piece.0 {
+            let absolute_pos =
+                (piece_pos.0 + pos.0 .0, piece_pos.1 + pos.1 .0);
+            assert!(!self.grid[absolute_pos.0][absolute_pos.1]);
+            self.grid[absolute_pos.0][absolute_pos.1] = true;
+        }
+    }
+
+    fn shrink(&mut self) {
+        let height = self
+            .grid
+            .each_col()
+            .map(|col| {
+                self.grid
+                    .each_row()
+                    .rev()
+                    .find(|row| self.grid[*row][col])
+                    .map(|row| row.0 + 1)
+                    .unwrap_or(0)
+            })
+            .min()
+            .unwrap_or(0);
+        self.grid.unshift_rows(height);
+        self.extra_height += height;
+    }
+
+    fn seen_grid_hash(&mut self, idx: usize) -> Option<usize> {
+        use std::hash::{Hash as _, Hasher as _};
+        let mut hasher = ahash::AHasher::default();
+        self.grid.hash(&mut hasher);
+        idx.hash(&mut hasher);
+        let hash = hasher.finish();
+        let ret = self.seen.get(&hash).copied();
+        self.seen.insert(hash, self.piece_idx);
+        ret
+    }
+
+    fn height(&self) -> usize {
+        self.grid
+            .each_row()
+            .rev()
+            .find(|row| self.grid[*row].iter().any(|c| *c))
+            .map(|row| row.0 + 1)
+            .unwrap_or(0)
+    }
+}
+
+pub fn parse(fh: File) -> Result<Vec<Direction>> {
+    Ok(parse::bytes(fh)
+        .take_while(|c| *c == b'<' || *c == b'>')
+        .map(|c| c.try_into().unwrap())
+        .collect())
+}
+
+pub fn part1(directions: Vec<Direction>) -> Result<usize> {
+    let mut chamber = Chamber::default();
+    for (i, direction) in directions.iter().copied().enumerate().cycle() {
+        if let Some((dropped, prev)) = chamber.step(i, direction) {
+            if dropped + 1 >= 2022 {
+                break;
+            }
+        }
+    }
+    Ok(chamber.height() + chamber.extra_height)
+}
+
+pub fn part2(directions: Vec<Direction>) -> Result<usize> {
+    let mut chamber = Chamber::default();
+    for (i, direction) in directions.iter().copied().enumerate().cycle() {
+        if let Some((dropped, Some(prev))) = chamber.step(i, direction) {
+            let cycle_len = dropped - prev;
+            let height_diff =
+                chamber.heights[dropped] - chamber.heights[prev];
+            let start_height = chamber.heights[prev];
+            let rest = 1_000_000_000_000 - (prev + 1);
+            let remaining_full_cycles = rest / cycle_len;
+            let partial_cycle_len = rest - remaining_full_cycles * cycle_len;
+            let partial_height_diff = chamber.heights
+                [prev + partial_cycle_len]
+                - chamber.heights[prev];
+            let height = start_height
+                + height_diff * remaining_full_cycles
+                + partial_height_diff;
+            return Ok(height);
+        }
+    }
+    unreachable!()
+}
+
+#[test]
+fn test() {
+    assert_eq!(
+        part1(parse(parse::data(2022, 17).unwrap()).unwrap()).unwrap(),
+        3083
+    );
+    assert_eq!(
+        part2(parse(parse::data(2022, 17).unwrap()).unwrap()).unwrap(),
+        1532183908048
+    );
+}
diff --git a/src/bin/2022/main.rs b/src/bin/2022/main.rs
index dff9ae4..744516a 100644
--- a/src/bin/2022/main.rs
+++ b/src/bin/2022/main.rs
@@ -27,6 +27,7 @@ mod day13;
 mod day14;
 mod day15;
 mod day16;
+mod day17;
 // NEXT MOD
 
 #[paw::main]
@@ -49,6 +50,7 @@ fn main(opt: Opt) -> Result<()> {
         14 => advent_of_code::day!(2022, opt.day, opt.puzzle, day14),
         15 => advent_of_code::day!(2022, opt.day, opt.puzzle, day15),
         16 => advent_of_code::day!(2022, opt.day, opt.puzzle, day16),
+        17 => advent_of_code::day!(2022, opt.day, opt.puzzle, day17),
         // NEXT PART
         _ => panic!("unknown day {}", opt.day),
     }
diff --git a/src/grid.rs b/src/grid.rs
index 96ac933..347c902 100644
--- a/src/grid.rs
+++ b/src/grid.rs
@@ -154,12 +154,12 @@ impl std::ops::Sub<ICol> for isize {
     }
 }
 
-#[derive(Default, Clone, Debug, Eq, PartialEq)]
-pub struct GridRow<T: Default + Clone + Eq + PartialEq> {
+#[derive(Default, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct GridRow<T: Default + Clone + Eq + PartialEq + std::hash::Hash> {
     cells: Vec<T>,
 }
 
-impl<T: Default + Clone + Eq + PartialEq> GridRow<T> {
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash> GridRow<T> {
     pub fn iter(&self) -> impl Iterator<Item = &T> + Clone {
         self.cells.iter()
     }
@@ -169,8 +169,8 @@ impl<T: Default + Clone + Eq + PartialEq> GridRow<T> {
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq> std::ops::Index<Col>
-    for GridRow<T>
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash>
+    std::ops::Index<Col> for GridRow<T>
 {
     type Output = T;
     fn index(&self, col: Col) -> &Self::Output {
@@ -178,20 +178,20 @@ impl<T: Default + Clone + Eq + PartialEq> std::ops::Index<Col>
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq> std::ops::IndexMut<Col>
-    for GridRow<T>
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash>
+    std::ops::IndexMut<Col> for GridRow<T>
 {
     fn index_mut(&mut self, col: Col) -> &mut Self::Output {
         &mut self.cells[col.0]
     }
 }
 
-#[derive(Default, Clone, Debug, Eq, PartialEq)]
-pub struct Grid<T: Default + Clone + Eq + PartialEq> {
+#[derive(Default, Clone, Debug, Eq, PartialEq, Hash)]
+pub struct Grid<T: Default + Clone + Eq + PartialEq + std::hash::Hash> {
     rows: Vec<GridRow<T>>,
 }
 
-impl<T: Default + Clone + Eq + PartialEq> Grid<T> {
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash> Grid<T> {
     pub fn grow(&mut self, rows: Row, cols: Col) {
         self.rows
             .resize_with(rows.0.max(self.rows.len()), GridRow::default);
@@ -201,6 +201,10 @@ impl<T: Default + Clone + Eq + PartialEq> Grid<T> {
         }
     }
 
+    pub fn unshift_rows(&mut self, count: usize) {
+        self.rows = self.rows.split_off(count);
+    }
+
     pub fn rows(&self) -> Row {
         Row(self.rows.len())
     }
@@ -267,7 +271,15 @@ impl<T: Default + Clone + Eq + PartialEq> Grid<T> {
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq + std::fmt::Display> Grid<T> {
+impl<
+        T: Default
+            + Clone
+            + Eq
+            + PartialEq
+            + std::hash::Hash
+            + std::fmt::Display,
+    > Grid<T>
+{
     pub fn display_packed<F: Fn(&T) -> char>(
         &self,
         f: F,
@@ -276,8 +288,14 @@ impl<T: Default + Clone + Eq + PartialEq + std::fmt::Display> Grid<T> {
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq + std::fmt::Display>
-    std::fmt::Display for Grid<T>
+impl<
+        T: Default
+            + Clone
+            + Eq
+            + PartialEq
+            + std::hash::Hash
+            + std::fmt::Display,
+    > std::fmt::Display for Grid<T>
 {
     fn fmt(
         &self,
@@ -293,22 +311,26 @@ impl<T: Default + Clone + Eq + PartialEq + std::fmt::Display>
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq> std::ops::Index<Row> for Grid<T> {
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash>
+    std::ops::Index<Row> for Grid<T>
+{
     type Output = GridRow<T>;
     fn index(&self, row: Row) -> &Self::Output {
         &self.rows[row.0]
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq> std::ops::IndexMut<Row>
-    for Grid<T>
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash>
+    std::ops::IndexMut<Row> for Grid<T>
 {
     fn index_mut(&mut self, row: Row) -> &mut Self::Output {
         &mut self.rows[row.0]
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq> FromIterator<Vec<T>> for Grid<T> {
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash>
+    FromIterator<Vec<T>> for Grid<T>
+{
     fn from_iter<I>(iter: I) -> Self
     where
         I: IntoIterator<Item = Vec<T>>,
@@ -319,8 +341,8 @@ impl<T: Default + Clone + Eq + PartialEq> FromIterator<Vec<T>> for Grid<T> {
     }
 }
 
-impl<T: Default + Clone + Eq + PartialEq> FromIterator<((Row, Col), T)>
-    for Grid<T>
+impl<T: Default + Clone + Eq + PartialEq + std::hash::Hash>
+    FromIterator<((Row, Col), T)> for Grid<T>
 {
     fn from_iter<I>(iter: I) -> Self
     where
@@ -337,13 +359,18 @@ impl<T: Default + Clone + Eq + PartialEq> FromIterator<((Row, Col), T)>
 
 pub struct DisplayPacked<
     'a,
-    T: Default + Clone + Eq + PartialEq + std::fmt::Display,
+    T: Default + Clone + Eq + PartialEq + std::hash::Hash + std::fmt::Display,
     F: Fn(&'a T) -> char,
 >(&'a Grid<T>, F);
 
 impl<
         'a,
-        T: Default + Clone + Eq + PartialEq + std::fmt::Display,
+        T: Default
+            + Clone
+            + Eq
+            + PartialEq
+            + std::hash::Hash
+            + std::fmt::Display,
         F: Fn(&'a T) -> char,
     > std::fmt::Display for DisplayPacked<'a, T, F>
 {
diff --git a/src/parse.rs b/src/parse.rs
index 1219484..6969e84 100644
--- a/src/parse.rs
+++ b/src/parse.rs
@@ -109,7 +109,7 @@ pub fn digit_grid(lines: impl Iterator<Item = String>) -> Grid<u8> {
 pub fn grid<F, T>(lines: impl Iterator<Item = String>, mut f: F) -> Grid<T>
 where
     F: FnMut(u8, Row, Col) -> T,
-    T: Clone + Default + Eq + PartialEq,
+    T: Clone + Default + Eq + PartialEq + std::hash::Hash,
 {
     lines
         .enumerate()