1 files changed, 85 insertions, 0 deletions

diff --git a/2022/17/common.rs b/2022/17/common.rs
new file mode 100644
index 0000000..d27ec3a
--- /dev/null
+++ b/2022/17/common.rs
@@ -0,0 +1,85 @@
+use std::cmp::max;
+
+pub const SCREEN_WIDTH: usize = 7;
+pub const SCREEN_HEIGHT: usize = 100000;
+
+pub struct Screen {
+    pub cell: [[bool; SCREEN_WIDTH]; SCREEN_HEIGHT],
+    pub top: usize
+}
+
+#[derive(Debug)]
+pub struct Rock {
+    pub a: Vec<(usize, usize)>,
+    pub h: usize
+}
+
+pub fn get_rocks() -> Vec<Rock> {
+    vec![
+        Rock { a: vec![(0, 0), (0, 1), (0, 2), (0, 3)], h: 1 },
+        Rock { a: vec![(0, 1), (1, 0), (1, 1), (1, 2), (2, 1)], h: 3 },
+        Rock { a: vec![(0, 0), (0, 1), (0, 2), (1, 2), (2, 2)], h: 3 },
+        Rock { a: vec![(0, 0), (1, 0), (2, 0), (3, 0)], h: 4 },
+        Rock { a: vec![(0, 0), (0, 1), (1, 0), (1, 1)], h: 2 }
+    ]
+}
+
+fn in_bounds(position: (i32, i32)) -> bool {
+    position.0 >= 0 && position.1 >= 0 && position.1 < SCREEN_WIDTH as i32
+}
+
+impl Screen {
+    pub fn new() -> Screen {
+        Screen {
+            cell: [[false; SCREEN_WIDTH]; SCREEN_HEIGHT],
+            top: 0
+        }
+    }
+
+    fn allowed(&self, rock: &Rock, p: (i32, i32)) -> bool {
+        for r in &rock.a {
+            let (i, j) = (r.0 as i32 + p.0, r.1 as i32 + p.1);
+            if !in_bounds((i, j)) || self.cell[i as usize][j as usize] {
+                return false;
+            }
+        }
+        true
+    }
+
+    fn draw(&mut self, rock: &Rock, p: (usize, usize), b: bool) {
+        for r in &rock.a {
+            self.cell[r.0 + p.0][r.1 + p.1] = b;
+        }
+    }
+
+    fn move_rock(&mut self, r: &Rock, p: (usize, usize), d: (i32, i32)) -> (usize, usize) {
+        let newpos = (p.0 as i32 + d.0, p.1 as i32 + d.1);
+        if !self.allowed(r, newpos) { return p; }
+        let newpos = (newpos.0 as usize, newpos.1 as usize);
+        newpos
+    }
+
+    pub fn drop_rock(&mut self, r: &Rock, t: &mut usize, gas: &str) {
+        let mut p = (self.top + 3, 2);
+        loop {
+            let d = gas.chars().nth(*t % gas.len()).unwrap();
+            let d = if d == '>' { (0, 1) } else { (0, -1) };
+            p = self.move_rock(r, p, d);
+            *t += 1;
+            let q = self.move_rock(r, p, (-1, 0));
+            if p == q { break; } else { p = q; }
+        }
+        self.draw(r, p, true);
+        self.top = max(self.top, p.0 + r.h);
+    }
+
+    #[allow(dead_code)]
+    pub fn print(&self) {
+        for i in (0..=self.top).rev() {
+            for j in 0..SCREEN_WIDTH {
+                print!("{}", if self.cell[i][j] { '#' } else { '.' })
+            }
+            println!(" {i}");
+        }
+    }
+}