day three, part one

day-3/src/main.rs

@@ -0,0 +1,24 @@
+use std::fs;
+
+use regex::Regex;
+
+pub fn parse(input: &str) -> Vec<(i32, i32)> {
+    let pattern = Regex::new(r"mul\((\d+),(\d+)\)").unwrap();
+    pattern.captures_iter(input).map(|caps| {
+        (caps.get(1).unwrap().as_str().parse().unwrap(), caps.get(2).unwrap().as_str().parse().unwrap())
+    }).collect()
+}
+
+fn main() {
+    let input = fs::read_to_string("input.txt").unwrap();
+
+    let parsed = parse(&input);
+
+    let mut sum = 0;
+
+    for (x, y) in parsed {
+        sum += x * y;
+    }
+
+    println!("{sum}");
+}