Add day 1

src/bin/day1.rs

@@ -0,0 +1,57 @@
+use aoc2022::StdError;
+use std::fs::File;
+use std::io::{BufRead, BufReader};
+
+struct BlanklineSplitter<T: Iterator> {
+    iter: T,
+}
+
+impl<T: Iterator<Item = String>> BlanklineSplitter<T> {
+    fn new(iter: T) -> Self {
+        BlanklineSplitter { iter }
+    }
+}
+
+impl<T: Iterator<Item = String>> Iterator for BlanklineSplitter<T> {
+    type Item = Vec<String>;
+    fn next(&mut self) -> Option<Self::Item> {
+        let mut acc = vec![];
+        loop {
+            match self.iter.next().as_deref() {
+                Some("") => {
+                    // Skip over multiple empty lines
+                    if !acc.is_empty() {
+                        break;
+                    }
+                }
+                Some(l) => acc.push(l.into()),
+                None => break,
+            }
+        }
+        if acc.is_empty() {
+            return None;
+        } else {
+            return Some(acc);
+        }
+    }
+}
+
+fn main() -> StdError<()> {
+    let lines = BufReader::new(File::open("input/day1.txt")?)
+        .lines()
+        .filter_map(Result::ok);
+    let mut sums: Vec<_> = BlanklineSplitter::new(lines)
+        .map(|e| {
+            e.iter()
+                .map(|l| l.parse::<u32>())
+                .filter_map(Result::ok)
+                .sum::<u32>()
+        })
+        .collect();
+    sums.sort_by(|a, b| b.cmp(a));
+    let max = sums.iter().max().unwrap();
+    println!("Part 1: {}", max);
+    let top3 = sums[0..3].iter().sum::<u32>();
+    println!("Part 2: {}", top3);
+    Ok(())
+}

src/lib.rs

@@ -0,0 +1 @@
+pub type StdError<T> = Result<T, Box<dyn std::error::Error>>;

src/main.rs

@@ -0,0 +1,3 @@
+fn main() {
+    println!("Hello, world!");
+}