2022 day4/rust: add solution

2022/day4/rust/Cargo.toml

@@ -0,0 +1,8 @@
+[package]
+name = "rust_2022_04"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

2022/day4/rust/src/main.rs

@@ -0,0 +1,45 @@
+use std::io::{stdin, Read};
+
+fn main() {
+    let mut data = String::new();
+    stdin().read_to_string(&mut data).unwrap();
+
+    let pairs: Vec<_> = data
+        .lines()
+        .map(|line| {
+            let make_range = |s: &str| {
+                let (start, end) = s.split_once('-').unwrap();
+
+                let start: u64 = start.parse().unwrap();
+                let end = end.parse().unwrap();
+
+                assert!(start <= end);
+                start..=end
+            };
+
+            let (left, right) = line.split_once(',').unwrap();
+            let left = make_range(left);
+            let right = make_range(right);
+
+            (left, right)
+        })
+        .collect();
+
+    println!(
+        "{}",
+        pairs
+            .iter()
+            .filter(|(l, r)| l.start() == r.start()
+                || l.end() == r.end()
+                || l.start().cmp(r.start()) != l.end().cmp(r.end()))
+            .count()
+    );
+
+    println!(
+        "{}",
+        pairs
+            .iter()
+            .filter(|(l, r)| l.end() >= r.start() && r.end() >= l.start())
+            .count()
+    );
+}

Cargo.lock

@@ -473,6 +473,10 @@ version = "0.1.0"
 name = "rust_2022_03"
 version = "0.1.0"
 
+[[package]]
+name = "rust_2022_04"
+version = "0.1.0"
+
 [[package]]
 name = "ryu"
 version = "1.0.11"

Cargo.toml

@@ -12,4 +12,5 @@ members = [
 	"2022/day1/rust",
 	"2022/day2/rust",
 	"2022/day3/rust",
+	"2022/day4/rust",
 ]