2024-01 rust p1,p2

3 files changed, 44 insertions, 0 deletions

diff --git a/2024/01/rust/Cargo.lock b/2024/01/rust/Cargo.lock
new file mode 100644
index 0000000..7010c56
--- /dev/null
+++ b/2024/01/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_2024-01"
+version = "0.1.0"
diff --git a/2024/01/rust/Cargo.toml b/2024/01/rust/Cargo.toml
new file mode 100644
index 0000000..0e9bfaa
--- /dev/null
+++ b/2024/01/rust/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "aoc_2024-01"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
diff --git a/2024/01/rust/src/main.rs b/2024/01/rust/src/main.rs
new file mode 100644
index 0000000..c1648cf
--- /dev/null
+++ b/2024/01/rust/src/main.rs
@@ -0,0 +1,31 @@
+use std::collections::HashMap;
+use std::io;
+
+fn main() -> io::Result<()> {
+    let (mut ls, mut rs): (Vec<u64>, Vec<u64>) = io::stdin()
+        .lines()
+        .map(|line| {
+            line.unwrap()
+                .split_whitespace()
+                .map(|s| s.parse().unwrap())
+                .collect::<Vec<u64>>()
+        })
+        .map(|xs| (xs[0], xs[1]))
+        .unzip();
+
+    ls.sort_unstable();
+    rs.sort_unstable();
+
+    let mut counts = HashMap::new();
+    rs.iter().for_each(|&x| {
+        *counts.entry(x).or_insert(0) += 1;
+    });
+
+    let silver: u64 = ls.iter().zip(rs).map(|(x, y)| x.abs_diff(y)).sum();
+    let gold: u64 = ls.iter().map(|x| x * counts.get(x).unwrap_or(&0)).sum();
+
+    println!("silver: {silver}");
+    println!("gold: {gold}");
+
+    return Ok(());
+}