2024-06 rust p1

4 files changed, 74 insertions, 6 deletions

diff --git a/2024/06/rust/Cargo.lock b/2024/06/rust/Cargo.lock
new file mode 100644
index 0000000..a049cf0
--- /dev/null
+++ b/2024/06/rust/Cargo.lock
@@ -0,0 +1,14 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "aoc"
+version = "0.1.0"
+
+[[package]]
+name = "aoc_2024-06"
+version = "0.1.0"
+dependencies = [
+ "aoc",
+]
diff --git a/2024/06/rust/Cargo.toml b/2024/06/rust/Cargo.toml
new file mode 100644
index 0000000..f478719
--- /dev/null
+++ b/2024/06/rust/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "aoc_2024-06"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+aoc = { version = "0.1.0", path = "../../../lib/rust" }
diff --git a/2024/06/rust/src/main.rs b/2024/06/rust/src/main.rs
new file mode 100644
index 0000000..92ac02d
--- /dev/null
+++ b/2024/06/rust/src/main.rs
@@ -0,0 +1,43 @@
+use std::io;
+
+use aoc::grid::{Direction, Grid};
+use std::collections::HashSet;
+
+fn main() -> io::Result<()> {
+    let grid: Vec<Vec<char>> = io::stdin()
+        .lines()
+        .map(|line| line.unwrap().chars().collect())
+        .collect();
+    let grid = Grid::new(grid);
+    let start = grid
+        .enumerate()
+        .filter(|(_, c)| **c == '^')
+        .next()
+        .unwrap()
+        .0;
+
+    let silver: usize = silver(&grid, start);
+    let gold: usize = gold(&grid);
+    println!("silver: {silver}");
+    println!("gold: {gold}");
+
+    return Ok(());
+}
+
+fn silver(grid: &Grid<char>, start: (usize, usize)) -> usize {
+    let mut pos = start;
+    let mut dir = Direction { x: 0, y: -1 };
+    let mut seen = HashSet::<(usize, usize)>::new();
+    loop {
+        seen.insert(pos);
+        match grid.move_pos(pos, dir, 1).and_then(|p| grid.at(p)) {
+            Some(&'#') => dir = dir.cw(),
+            Some(_) => pos = grid.move_pos(pos, dir, 1).unwrap(),
+            None => break seen.len(),
+        }
+    }
+}
+
+fn gold(grid: &Grid<char>) -> usize {
+    0
+}
diff --git a/lib/rust/src/grid.rs b/lib/rust/src/grid.rs
index 1b43852..671c7de 100644
--- a/lib/rust/src/grid.rs
+++ b/lib/rust/src/grid.rs
@@ -9,8 +9,8 @@ type Point = (usize, usize);
 
 #[derive(PartialEq, Eq, Clone, Hash, Debug, Copy)]
 pub struct Direction {
-    x: i64,
-    y: i64,
+    pub x: i64,
+    pub y: i64,
 }
 
 impl From<(i64, i64)> for Direction {
@@ -20,12 +20,12 @@ impl From<(i64, i64)> for Direction {
 }
 
 impl Direction {
-    fn cw(self) -> Self {
-        (self.y, -self.x).into()
-    }
-    fn acw(self) -> Self {
+    pub fn cw(self) -> Self {
         (-self.y, self.x).into()
     }
+    pub fn acw(self) -> Self {
+        (self.y, -self.x).into()
+    }
 }
 
 pub fn chebyshev_ball(n: i64) -> impl Iterator<Item = Direction> {
@@ -58,6 +58,10 @@ impl<T> Grid<T> {
         (0..self.width).flat_map(|x| (0..self.height).map(move |y| (x, y)))
     }
 
+    pub fn enumerate(&self) -> impl Iterator<Item = (Point, &T)> {
+        self.points().map(|p| (p, self.at(p).unwrap()))
+    }
+
     pub fn move_pos(&self, (x, y): Point, d: Direction, n: i64) -> Option<Point> {
         let x = (i64::try_from(x).ok()? + n * d.x).try_into().ok()?;
         let y = (i64::try_from(y).ok()? + n * d.y).try_into().ok()?;