25-09 rust

3 files changed, 40 insertions, 0 deletions

diff --git a/2025/09/rust/Cargo.lock b/2025/09/rust/Cargo.lock
new file mode 100644
index 0000000..1a33f1f
--- /dev/null
+++ b/2025/09/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 = "aoc_2025-09"
+version = "0.1.0"
diff --git a/2025/09/rust/Cargo.toml b/2025/09/rust/Cargo.toml
new file mode 100644
index 0000000..a713c42
--- /dev/null
+++ b/2025/09/rust/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "aoc_2025-09"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
diff --git a/2025/09/rust/src/main.rs b/2025/09/rust/src/main.rs
new file mode 100644
index 0000000..0a60ece
--- /dev/null
+++ b/2025/09/rust/src/main.rs
@@ -0,0 +1,27 @@
+use std::io;
+
+fn main() {
+    let pts = io::stdin()
+        .lines()
+        .flatten()
+        .map(|line| {
+            let (x, y) = line.split_once(',').unwrap();
+            (x.parse().unwrap(), y.parse().unwrap())
+        })
+        .collect::<Vec<(u64, u64)>>();
+
+    let silver: u64 = pts
+        .iter()
+        .enumerate()
+        .flat_map(|(idx, p1)| pts.iter().take(idx).map(move |p2| area(*p1, *p2)))
+        .max()
+        .unwrap();
+
+    let gold: u64 = 0;
+    println!("silver: {silver}");
+    println!("gold: {gold}");
+}
+
+fn area((x1, y1): (u64, u64), (x2, y2): (u64, u64)) -> u64 {
+    (x1.abs_diff(x2) + 1) * (y1.abs_diff(y2) + 1)
+}