From 6b5aed016bc40ebcf0ca699c2c598b7195101ab9 Mon Sep 17 00:00:00 2001
From: Johannes <freelon@gmx.net>
Date: Tue, 3 Dec 2024 06:07:59 +0100
Subject: [PATCH] day 3 part 1

---
 Cargo.lock   | 45 +++++++++++++++++++++++++++++++++++++++++++++
 Cargo.toml   |  1 +
 src/day03.rs | 20 ++++++++++++++++----
 3 files changed, 62 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index 68b0027..206637a 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -7,6 +7,16 @@ name = "advent-of-rust-2024"
 version = "0.1.0"
 dependencies = [
  "itertools",
+ "regex",
+]
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8e60d3430d3a69478ad0993f19238d2df97c507009a52b3c10addcd7f6bcb916"
+dependencies = [
+ "memchr",
 ]
 
 [[package]]
@@ -23,3 +33,38 @@ checksum = "413ee7dfc52ee1a4949ceeb7dbc8a33f2d6c088194d9f922fb8318faf1f01186"
 dependencies = [
  "either",
 ]
+
+[[package]]
+name = "memchr"
+version = "2.7.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78ca9ab1a0babb1e7d5695e3530886289c18cf2f87ec19a575a0abdce112e3a3"
+
+[[package]]
+name = "regex"
+version = "1.11.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b544ef1b4eac5dc2db33ea63606ae9ffcfac26c1416a2806ae0bf5f56b201191"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "809e8dc61f6de73b46c85f4c96486310fe304c434cfa43669d7b40f711150908"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2b15c43186be67a4fd63bee50d0303afffcef381492ebe2c5d87f324e1b8815c"
diff --git a/Cargo.toml b/Cargo.toml
index ea8ff06..9abeeaa 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -5,3 +5,4 @@ edition = "2021"
 
 [dependencies]
 itertools = "0.13.0"
+regex = "1.11.1"
diff --git a/src/day03.rs b/src/day03.rs
index d581495..f48e236 100644
--- a/src/day03.rs
+++ b/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]