[rs] Solve 2022_04 part 1

rs/src/y2022/d04.rs

@@ -0,0 +1,24 @@
+use std::ops::RangeInclusive;
+
+fn contains(a: &RangeInclusive<u32>, b: &RangeInclusive<u32>) -> bool {
+    a.start() <= b.start() && b.end() <= a.end()
+}
+
+pub fn solve(input: String) {
+    let pairs = input
+        .lines()
+        .map(|l| {
+            let mut ranges = l.split(',').map(|p| {
+                let mut numbers = p.split('-').map(|n| n.parse::<u32>().unwrap());
+                numbers.next().unwrap()..=numbers.next().unwrap()
+            });
+            (ranges.next().unwrap(), ranges.next().unwrap())
+        })
+        .collect::<Vec<_>>();
+
+    let score = pairs
+        .iter()
+        .filter(|(a, b)| contains(a, b) || contains(b, a))
+        .count();
+    println!("Part 1: {score}");
+}