Day 3

1 files changed, 43 insertions, 0 deletions

diff --git a/src/bin/day03.rs b/src/bin/day03.rs
new file mode 100644
index 0000000..8116acb
--- /dev/null
+++ b/src/bin/day03.rs
@@ -0,0 +1,43 @@
+use std::io::{self, Read};
+use std::str::FromStr;
+
+struct Triangle(u32, u32, u32);
+
+impl Triangle {
+    fn valid(&self) -> bool {
+        self.0 + self.1 > self.2
+            && self.1 + self.2 > self.0
+            && self.0 + self.2 > self.1
+    }
+}
+
+impl FromStr for Triangle {
+    type Err = ();
+    fn from_str(s: &str) -> Result<Self, ()> {
+        let mut iter = s.split_whitespace().map(str::parse);
+        match (iter.next(), iter.next(), iter.next()) {
+            (Some(Ok(a)), Some(Ok(b)), Some(Ok(c))) => Ok(Triangle(a, b, c)),
+            _ => Err(()),
+        }
+    }
+}
+
+fn solve(input: &str) -> usize {
+    input.lines()
+        .map(str::parse)
+        .map(Result::unwrap)
+        .filter(Triangle::valid)
+        .count()
+}
+
+fn main() {
+    let mut input = String::new();
+    io::stdin().read_to_string(&mut input).unwrap();
+
+    println!("Part 1: {}", solve(&input));
+}
+
+#[test]
+fn part1() {
+    assert_eq!(0, solve("5 10 25"));
+}