2022: day 01 part 1

aoc2022/src/day01.rs

@@ -0,0 +1,63 @@
+use std::fmt::Write;
+
+use anyhow::{Context, Result};
+
+const INPUT: &str = include_str!("../input/day01.txt");
+
+pub fn run() -> Result<String> {
+    let mut res = String::with_capacity(128);
+
+    writeln!(res, "part 1: {}", part1(INPUT)?)?;
+
+    Ok(res)
+}
+
+fn part1(input: &str) -> Result<u64> {
+    let inventories = input
+        .split("\n\n")
+        .map(str::parse::<Inventory>)
+        .collect::<Result<Vec<_>>>()?;
+
+    inventories
+        .iter()
+        .map(Inventory::total_calories)
+        .max()
+        .context("inventory list was empty")
+}
+
+struct Inventory(Vec<u64>);
+
+impl std::str::FromStr for Inventory {
+    type Err = anyhow::Error;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(Inventory(
+            s.lines()
+                .map(|line| line.parse::<u64>().map_err(anyhow::Error::new))
+                .collect::<Result<Vec<_>>>()?,
+        ))
+    }
+}
+
+impl Inventory {
+    fn total_calories(&self) -> u64 {
+        self.0.iter().sum()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const PROVIDED: &str = include_str!("../input/day01_provided.txt");
+
+    #[test]
+    fn part1_provided() {
+        assert_eq!(part1(PROVIDED).unwrap(), 24000);
+    }
+
+    #[test]
+    fn part1_real() {
+        assert_eq!(part1(INPUT).unwrap(), 68923);
+    }
+}

aoc2022/src/lib.rs

@@ -0,0 +1,3 @@
+#![warn(clippy::explicit_iter_loop, clippy::redundant_closure_for_method_calls)]
+
+pub mod day01;

aoc2022/src/main.rs

@@ -0,0 +1,11 @@
+use anyhow::Result;
+
+use aoc::DayFunc;
+
+use aoc2022::day01;
+
+fn main() -> Result<()> {
+    let days: &[DayFunc] = &[day01::run];
+
+    aoc::run(days)
+}