Solve day 4

input/04-test

@@ -0,0 +1,6 @@
+2-4,6-8
+2-3,4-5
+5-7,7-9
+2-8,3-7
+6-6,4-6
+2-6,4-8

src/bin/04.rs

@@ -0,0 +1,63 @@
+use aoc2022::*;
+
+const INPUT: &str = include_str!("../../input/04");
+
+fn main() {
+    let solution = INPUT
+        .lines()
+        .map(parse_line)
+        .filter(|&(a, b)| a.contains(b) || b.contains(a))
+        .count();
+    solved_level_1(solution);
+
+    let solution = INPUT
+        .lines()
+        .map(parse_line)
+        .filter(|&(a, b)| a.overlaps(b))
+        .count();
+    solved_level_2(solution);
+}
+
+fn parse_line(line: &str) -> (Range, Range) {
+    let (a, b) = line.split_once(',').unwrap();
+    (a.into(), b.into())
+}
+
+#[derive(Clone, Copy)]
+struct Range {
+    start: i64,
+    end: i64,
+}
+
+impl Range {
+    fn contains<O>(self, other: O) -> bool
+    where
+        O: Into<Self>,
+    {
+        let other = other.into();
+        other.start >= self.start && other.end <= self.end
+    }
+
+    fn overlaps(self, other: Self) -> bool {
+        self.contains(other.start)
+            || self.contains(other.end)
+            || other.contains(self.start)
+            || other.contains(self.end)
+    }
+}
+
+impl From<&str> for Range {
+    fn from(s: &str) -> Self {
+        let (start, end) = s.split_once('-').unwrap();
+        Self {
+            start: start.parse().unwrap(),
+            end: end.parse().unwrap(),
+        }
+    }
+}
+
+impl From<i64> for Range {
+    fn from(n: i64) -> Self {
+        Self { start: n, end: n }
+    }
+}