Day 1

.gitignore

@@ -1 +1,2 @@
 /target
+.DS_Store

Cargo.lock

@@ -0,0 +1,54 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "aho-corasick"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b2969dcb958b36655471fc61f7e416fa76033bdd4bfed0678d8fee1e2d07a1f0"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "aoc23"
+version = "0.1.0"
+dependencies = [
+ "regex",
+]
+
+[[package]]
+name = "memchr"
+version = "2.6.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f665ee40bc4a3c5590afb1e9677db74a508659dfd71e126420da8274909a0167"
+
+[[package]]
+name = "regex"
+version = "1.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "380b951a9c5e80ddfd6136919eef32310721aa4aacd4889a8d39124b026ab343"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5f804c7828047e88b2d32e2d7fe5a105da8ee3264f01902f796c8e067dc2483f"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.8.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c08c74e62047bb2de4ff487b251e4a92e24f48745648451635cec7d591162d9f"

Cargo.toml

@@ -6,3 +6,4 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+regex = "1.10"

src/day01.rs

@@ -0,0 +1,80 @@
+use regex::Regex;
+
+pub fn run() {
+    let input = include_str!("../input/day1.txt");
+    // let input = r#"1abc2
+    // pqr3stu8vwx
+    // a1b2c3d4e5f
+    // treb7uchet"#;
+    // let input = r#"two1nine
+    // eightwothree
+    // abcone2threexyz
+    // xtwone3four
+    // 4nineeightseven2
+    // zoneight234
+    // 7pqrstsixteen"#;
+
+    // let sum: u32 = input
+    //     .lines()
+    //     .filter(|s| !s.is_empty())
+    //     .map(|s| find_digits(s))
+    //     .sum();
+    // dbg!(sum);
+
+    dbg!(find_digits_part2("gdgj3f"));
+
+    let sum2 = input
+        .lines()
+        .filter(|s| !s.is_empty())
+        .map(|s| find_digits_part2(s))
+        .sum::<u32>();
+    dbg!(sum2);
+}
+
+fn find_digits(s: &str) -> u32 {
+    let first = s
+        .chars()
+        .nth(s.find(|c: char| c.is_ascii_digit()).unwrap())
+        .unwrap()
+        .to_digit(10)
+        .unwrap();
+    let last = s
+        .chars()
+        .nth(s.rfind(|c: char| c.is_ascii_digit()).unwrap())
+        .unwrap()
+        .to_digit(10)
+        .unwrap();
+    first * 10 + last
+}
+
+fn find_digits_part2(s: &str) -> u32 {
+    let re = Regex::new("^([1-9]|one|two|three|four|five|six|seven|eight|nine)").unwrap();
+    let mut s = s.to_owned();
+    let mut first: Option<u32> = None;
+    let mut last: Option<u32> = None;
+    while !s.is_empty() {
+        if let Some(m) = re.find(&s) {
+            last = Some(parse_digit(m.as_str()));
+            if first == None {
+                first = last;
+            }
+        }
+        s.remove(0);
+    }
+    return first.unwrap() * 10 + last.unwrap();
+}
+
+fn parse_digit(s: &str) -> u32 {
+    match s {
+        "one" => 1,
+        "two" => 2,
+        "three" => 3,
+        "four" => 4,
+        "five" => 5,
+        "six" => 6,
+        "seven" => 7,
+        "eight" => 8,
+        "nine" => 9,
+        _ => s.parse().unwrap(),
+    }
+}

src/main.rs

@@ -1,3 +1,5 @@
+mod day01;
+
 fn main() {
-    println!("Hello, world!");
+    day01::run();
 }