day 3 part 1

src/day03.rs

@@ -2,14 +2,26 @@ use std::fs::read_to_string;
 
 pub fn day_main() {
     let input = read_to_string("input/day03.txt").unwrap();
+    let input = input.trim();
     println!("part1: {}", part1(&input));
     println!("part2: {}", part2(&input));
 }
 
-type RiddleResult = usize;
+type RiddleResult = i64;
 
 fn part1(input: &str) -> RiddleResult {
-    0
+    let r = regex::Regex::new(r"mul\(\d{1,3},\d{1,3}\)").unwrap();
+    r.captures_iter(input)
+        .map(|c| {
+            let s = c.get(0).unwrap().as_str();
+            println!("{s}");
+            let x = s.strip_prefix("mul(").unwrap().strip_suffix(")").unwrap();
+            let (a, b) = x.split_once(',').unwrap();
+            let a: i64 = a.parse().unwrap();
+            let b: i64 = b.parse().unwrap();
+            a * b
+        })
+        .sum()
 }
 
 fn part2(_input: &str) -> RiddleResult {
@@ -20,12 +32,12 @@ fn part2(_input: &str) -> RiddleResult {
 mod test {
     use super::{part1, part2};
 
-    const TEST_INPUT: &str = r"
+    const TEST_INPUT: &str = r"xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))
 ";
 
     #[test]
     fn test1() {
-        assert_eq!(part1(TEST_INPUT), 0);
+        assert_eq!(part1(TEST_INPUT), 161);
     }
 
     #[test]