day 3

src/bin/day03_1.rs

@@ -0,0 +1,7 @@
+use aoc2022::day03::process_part_1;
+use std::fs;
+
+fn main() {
+    let file = fs::read_to_string("./inputs/day3.txt").unwrap();
+    println!("{}", process_part_1(&file));
+}

src/bin/day03_2.rs

@@ -0,0 +1,7 @@
+use aoc2022::day03::process_part_2;
+use std::fs;
+
+fn main() {
+    let file = fs::read_to_string("./inputs/day3.txt").unwrap();
+    println!("{}", process_part_2(&file));
+}

src/day03.rs

@@ -0,0 +1,68 @@
+use itertools::Itertools;
+
+pub fn process_part_1(input: &str) -> u32 {
+    input
+        .lines()
+        .map(|line| {
+            let compartments = line.split_at(line.len() / 2);
+            let overlap = compartments
+                .0
+                .chars()
+                .find(|ch| compartments.1.contains(*ch))
+                .expect("There should be one overlapping item");
+
+            match overlap {
+                'a'..='z' => 1 + overlap as u32 - 'a' as u32,
+                'A'..='Z' => 27 + overlap as u32 - 'A' as u32,
+                _ => panic!("Invalid overlapping item"),
+            }
+        })
+        .sum()
+}
+
+pub fn process_part_2(input: &str) -> u32 {
+    let result = input
+        .lines()
+        .chunks(3)
+        .into_iter()
+        .map(|chunk| {
+            let lines: Vec<_> = chunk
+                .map(|l| l.chars().unique().collect::<Vec<_>>())
+                .collect();
+
+            let overlap = *lines[0]
+                .iter()
+                .find(|c| lines[1].contains(*c) && lines[2].contains(*c))
+                .unwrap();
+
+            match overlap {
+                'a'..='z' => 1 + overlap as u32 - 'a' as u32,
+                'A'..='Z' => 27 + overlap as u32 - 'A' as u32,
+                _ => panic!("Invalid overlapping item"),
+            }
+        })
+        .sum();
+    return result;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const INPUT: &str = "vJrwpWtwJgWrhcsFMMfFFhFp
+jqHRNqRjqzjGDLGLrsFMfFZSrLrFZsSL
+PmmdzqPrVvPwwTWBwg
+wMqvLMZHhHMvwLHjbvcjnnSBnvTQFn
+ttgJtRGJQctTZtZT
+CrZsJsPPZsGzwwsLwLmpwMDw";
+
+    #[test]
+    fn day1() {
+        assert_eq!(process_part_1(INPUT), 157);
+    }
+
+    #[test]
+    fn day2() {
+        assert_eq!(process_part_2(INPUT), 70);
+    }
+}

src/lib.rs

@@ -1,2 +1,5 @@
+extern crate core;
+
 pub mod day01;
 pub mod day02;
+pub mod day03;