1 files changed, 61 insertions, 0 deletions
diff --git a/2022/src/bin/day_1.rs b/2022/src/bin/day_1.rs
new file mode 100644
index 0000000..bc988b7
--- /dev/null
+++ b/2022/src/bin/day_1.rs
@@ -0,0 +1,61 @@
+use nom::{
+    character::complete::{line_ending, u32 as nom_u32},
+    combinator::map,
+    multi::separated_list1,
+    sequence::pair,
+    IResult,
+};
+use std::fs;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let input = fs::read_to_string("inputs/day_1.txt")?;
+    let elves = Elves::parser(&input).unwrap().1;
+    dbg!(elves.max_calories_sum(1));
+    dbg!(elves.max_calories_sum(3));
+    Ok(())
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone)]
+struct Elves {
+    elves: Vec<Elf>,
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone)]
+struct Elf {
+    calories: Vec<u32>,
+}
+
+impl Elves {
+    fn parser(input: &str) -> IResult<&str, Elves> {
+        map(
+            separated_list1(pair(line_ending, line_ending), Elf::parser),
+            Elves::new,
+        )(input)
+    }
+
+    fn new(mut elves: Vec<Elf>) -> Elves {
+        elves.sort_unstable_by_key(|elf| elf.total_calories());
+        Elves { elves }
+    }
+
+    fn max_calories_sum(&self, count: usize) -> u32 {
+        self.elves
+            .iter()
+            .rev()
+            .take(count)
+            .map(|elf| elf.total_calories())
+            .sum()
+    }
+}
+
+impl Elf {
+    fn parser(input: &str) -> IResult<&str, Elf> {
+        map(separated_list1(line_ending, nom_u32), |calories| Elf {
+            calories,
+        })(input)
+    }
+
+    fn total_calories(&self) -> u32 {
+        self.calories.iter().sum()
+    }
+}