day-03 part-1

2024/day-03/src/bin/part1.rs

@@ -0,0 +1,12 @@
+use day_03::part1::process;
+use miette::{Context, Result};
+
+#[tracing::instrument]
+fn main() -> Result<()> {
+    tracing_subscriber::fmt::init();
+
+    let file = include_str!("../../input1.txt");
+    let result = process(file).context("process part 1")?;
+    println!("{}", result);
+    Ok(())
+}

2024/day-03/src/bin/part2.rs

@@ -0,0 +1,12 @@
+use day_03::part2::process;
+use miette::{Context, Result};
+
+#[tracing::instrument]
+fn main() -> Result<()> {
+    tracing_subscriber::fmt::init();
+
+    let file = include_str!("../../input2.txt");
+    let result = process(file).context("process part 2")?;
+    println!("{}", result);
+    Ok(())
+}

2024/day-03/src/lib.rs

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+pub mod part1;
+pub mod part2;

2024/day-03/src/part1.rs

@@ -0,0 +1,62 @@
+use std::num::ParseIntError;
+
+use miette::Result;
+use regex::Regex;
+
+#[derive(Debug)]
+struct Multiplication(usize, usize);
+
+impl Multiplication {
+    fn calculate(&self) -> usize {
+        self.0 * self.1
+    }
+}
+
+impl<T, U> TryFrom<(T, U)> for Multiplication
+where
+    T: Into<String>,
+    U: Into<String>,
+{
+    type Error = ParseIntError;
+    fn try_from(value: (T, U)) -> std::result::Result<Self, Self::Error> {
+        Ok(Self(
+            value.0.into().parse::<usize>()?,
+            value.1.into().parse::<usize>()?,
+        ))
+    }
+}
+
+fn extract_multiplications<'a>(
+    line: &'a str,
+    re: &'a Regex,
+) -> impl Iterator<Item = Multiplication> + 'a {
+    re.captures_iter(line).filter_map(|caps| {
+        let first = caps.get(1)?.as_str().to_owned();
+        let second = caps.get(2)?.as_str().to_owned();
+        Multiplication::try_from((first, second)).ok()
+    })
+}
+
+#[tracing::instrument]
+pub fn process(input: &str) -> Result<usize> {
+    let re = Regex::new(r"mul\((\d{1,3}),(\d{1,3})\)").unwrap();
+    let result = input
+        .lines()
+        .flat_map(|line| extract_multiplications(line, &re))
+        .map(|mult| mult.calculate())
+        .sum();
+    Ok(result)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_process() -> Result<()> {
+        let input = "xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))";
+        let result = 161;
+        assert_eq!(process(input)?, result);
+        Ok(())
+    }
+}

2024/day-03/src/part2.rs

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+use miette::Result;
+
+#[tracing::instrument]
+pub fn process(input: &str) -> Result<usize> {
+    todo!("day xx - part 2");
+    Ok(0)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_process() -> Result<()> {
+        let input = "";
+        todo!("haven't built test yet");
+        let result = 0;
+        assert_eq!(process(input)?, result);
+        Ok(())
+    }
+}