Upload day 1

README.md

@@ -6,6 +6,14 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 
 <!--- advent_readme_stars table --->
 
+<!--- benchmarking table --->
+## Benchmarks
+
+| Day | Part 1 | Part 2 |
+| :---: | :---: | :---:  |
+| [Day 1](./src/bin/01.rs) | `89.5µs` | `125.4µs` |
+
+**Total: 0.21ms**
 <!--- benchmarking table --->
 
 ---

src/bin/01.rs

@@ -0,0 +1,85 @@
+advent_of_code::solution!(1);
+use std::collections::HashMap;
+
+pub fn part_one(input: &str) -> Option<u32> {
+    if input.is_empty() {
+        return None;
+    }
+
+    let mut left: Vec<u32> = Vec::new();
+    let mut right: Vec<u32> = Vec::new();
+
+    for line in input.lines() {
+        let mut split = line.split_whitespace();
+
+        if let (Some(l), Some(r)) = (split.next(), split.next()) {
+            if let (Ok(l_number), Ok(r_number)) = (l.parse::<u32>(), r.parse::<u32>()) {
+                left.push(l_number);
+                right.push(r_number);
+            }
+        }
+    }
+
+    left.sort();
+    right.sort();
+
+    let total_distance: u32 = left
+        .iter()
+        .zip(right.iter())
+        .map(|(&x, &y)| if x > y { x - y } else { y - x })
+        .sum();
+
+    Some(total_distance)
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    if input.is_empty() {
+        return None;
+    }
+
+    let mut left: Vec<u32> = Vec::new();
+    let mut right: Vec<u32> = Vec::new();
+
+    for line in input.lines() {
+        let mut split = line.split_whitespace();
+
+        if let (Some(l), Some(r)) = (split.next(), split.next()) {
+            if let (Ok(l_number), Ok(r_number)) = (l.parse::<u32>(), r.parse::<u32>()) {
+                left.push(l_number);
+                right.push(r_number);
+            }
+        }
+    }
+
+    left.sort();
+    right.sort();
+
+    let mut right_list_counts: HashMap<u32, u32> = HashMap::new();
+    for &num in &right {
+        *right_list_counts.entry(num).or_insert(0) += 1;
+    }
+
+    let total_similarity_score: u32 = left
+        .iter()
+        .map(|&num| num * right_list_counts.get(&num).unwrap_or(&0))
+        .sum();
+
+    Some(total_similarity_score)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_part_one() {
+        let result = part_one(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, None);
+    }
+}