Solve year 2022 day 04

src/lib.rs

@@ -15,4 +15,5 @@ pub mod year2022 {
     pub mod day01;
     pub mod day02;
     pub mod day03;
+    pub mod day04;
 }

src/main.rs

@@ -85,5 +85,6 @@ fn year2022() -> Vec<Solution> {
         solution!(year2022, day01),
         solution!(year2022, day02),
         solution!(year2022, day03),
+        solution!(year2022, day04),
     ]
 }

src/year2022/day04.rs

@@ -0,0 +1,44 @@
+use crate::util::parse::ParseExt;
+
+fn solve(input: &str, filter: fn(u32, u32, u32, u32) -> bool) -> usize {
+    input
+        .lines()
+        .filter_map(|line| {
+            let mut nums = line.u32s();
+
+            if (filter)(nums.next()?, nums.next()?, nums.next()?, nums.next()?) {
+                Some(())
+            } else {
+                None
+            }
+        })
+        .count()
+}
+
+pub fn part1(input: &str) -> impl std::fmt::Display {
+    solve(input, |s1, e1, s2, e2| {
+        s1 <= s2 && e1 >= e2 || s1 >= s2 && e1 <= e2
+    })
+}
+
+pub fn part2(input: &str) -> impl std::fmt::Display {
+    solve(input, |s1, e1, s2, e2| {
+        s1 >= s2 && s1 <= e2 || s2 >= s1 && s2 <= e1
+    })
+}
+
+#[test]
+fn test_part1() {
+    assert_eq!(
+        "2",
+        part1("2-4,6-8\n2-3,4-5\n5-7,7-9\n2-8,3-7\n6-6,4-6\n2-6,4-8").to_string()
+    )
+}
+
+#[test]
+fn test_part2() {
+    assert_eq!(
+        "4",
+        part2("2-4,6-8\n2-3,4-5\n5-7,7-9\n2-8,3-7\n6-6,4-6\n2-6,4-8").to_string()
+    )
+}