From 86bac31392a76da84817eec020d2b84d099b3cc1 Mon Sep 17 00:00:00 2001
From: mhsn <mail@mhsn.net>
Date: Wed, 18 Mar 2026 21:48:13 +0000
Subject: add other challenges support

---
 aoc/2024/04/rust/Cargo.lock  |  7 ++++
 aoc/2024/04/rust/Cargo.toml  |  4 +++
 aoc/2024/04/rust/src/main.rs | 82 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 93 insertions(+)
 create mode 100644 aoc/2024/04/rust/Cargo.lock
 create mode 100644 aoc/2024/04/rust/Cargo.toml
 create mode 100644 aoc/2024/04/rust/src/main.rs

(limited to 'aoc/2024/04/rust')

diff --git a/aoc/2024/04/rust/Cargo.lock b/aoc/2024/04/rust/Cargo.lock
new file mode 100644
index 0000000..ac79b17
--- /dev/null
+++ b/aoc/2024/04/rust/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "puzzle"
+version = "0.1.0"
diff --git a/aoc/2024/04/rust/Cargo.toml b/aoc/2024/04/rust/Cargo.toml
new file mode 100644
index 0000000..5a7c59b
--- /dev/null
+++ b/aoc/2024/04/rust/Cargo.toml
@@ -0,0 +1,4 @@
+[package]
+name = "puzzle"
+version = "0.1.0"
+edition = "2021"
diff --git a/aoc/2024/04/rust/src/main.rs b/aoc/2024/04/rust/src/main.rs
new file mode 100644
index 0000000..191e461
--- /dev/null
+++ b/aoc/2024/04/rust/src/main.rs
@@ -0,0 +1,82 @@
+use std::io;
+
+fn main() -> io::Result<()> {
+    let grid = io::stdin()
+        .lines()
+        .flatten()
+        .map(|line| line.chars().collect())
+        .collect::<Vec<Vec<char>>>();
+    let grid = Grid(grid);
+
+    let silver: usize = silver(&grid);
+    let gold: usize = gold(&grid);
+
+    println!("silver: {silver}");
+    println!("gold: {gold}");
+
+    return Ok(());
+}
+
+struct Grid(Vec<Vec<char>>);
+
+impl Grid {
+    fn at(&self, (x, y): (isize, isize)) -> Option<&char> {
+        self.0
+            .get(usize::try_from(y).ok()?)?
+            .get(usize::try_from(x).ok()?)
+    }
+
+    fn check<'a>(
+        &self,
+        (x, y): (isize, isize),
+        mut pat: impl Iterator<Item = &'a ((isize, isize), char)>,
+    ) -> bool {
+        pat.all(|((dx, dy), ch)| self.at((x + dx, y + dy)).is_some_and(|c| c == ch))
+    }
+
+    fn pts(&self) -> impl Iterator<Item = (isize, isize)> + use<'_> {
+        (0..self.0[0].len()).flat_map(|x| (0..self.0.len()).map(move |y| (x as isize, y as isize)))
+    }
+}
+
+fn silver(grid: &Grid) -> usize {
+    let dirs = vec![
+        (-1, -1),
+        (-1, 0),
+        (-1, 1),
+        (0, -1),
+        (0, 1),
+        (1, -1),
+        (1, 0),
+        (1, 1),
+    ];
+
+    let xmases: Vec<Vec<((isize, isize), char)>> = dirs
+        .iter()
+        .map(|(dx, dy)| {
+            (0..4)
+                .map(move |n| (dx * n, dy * n))
+                .zip("XMAS".chars())
+                .collect()
+        })
+        .collect();
+
+    grid.pts()
+        .flat_map(|p| xmases.iter().map(move |xmas| grid.check(p, xmas.iter())))
+        .filter(|p| *p)
+        .count()
+}
+
+fn gold(grid: &Grid) -> usize {
+    let dirs = vec![(-1, -1), (1, -1), (0, 0), (-1, 1), (1, 1)];
+
+    let xmases: Vec<Vec<((isize, isize), char)>> = vec!["MMASS", "SMASM", "SSAMM", "MSAMS"]
+        .iter()
+        .map(|x| dirs.clone().into_iter().zip(x.chars()).collect())
+        .collect();
+
+    grid.pts()
+        .flat_map(|p| xmases.iter().map(move |xmas| grid.check(p, xmas.iter())))
+        .filter(|p| *p)
+        .count()
+}
-- 
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