feat: day 11

README.md

@@ -36,8 +36,9 @@ Solutions for [Advent of Code](https://adventofcode.com/) in [Rust](https://www.
 | [Day 8](./src/bin/08.rs) | `55.8µs` | `136.5µs` |
 | [Day 9](./src/bin/09.rs) | `942.7µs` | `122.7ms` |
 | [Day 10](./src/bin/10.rs) | `530.9µs` | `284.2µs` |
+| [Day 11](./src/bin/11.rs) | `238.7µs` | `12.7ms` |
 
-**Total: 436.23ms**
+**Total: 449.17ms**
 <!--- benchmarking table --->
 
 ---

data/examples/11.txt

@@ -0,0 +1 @@
+125 17

src/bin/11.rs

@@ -0,0 +1,58 @@
+use std::collections::HashMap;
+
+advent_of_code::solution!(11);
+
+pub fn solve(input: &str, iterations: usize) -> Option<u64> {
+    let mut stones: HashMap<u64, u64> = input
+        .split_whitespace()
+        .map(|x| (x.parse::<u64>().unwrap(), 1))
+        .collect();
+    for _ in 0..iterations {
+        let mut new_stones: HashMap<u64, u64> = HashMap::new();
+        for stone in stones.iter() {
+            let new = if *stone.0 == 0 {
+                vec![1]
+            } else {
+                let stone_str = stone.0.to_string();
+                if stone_str.len() % 2 == 0 {
+                    vec![
+                        stone_str[0..stone_str.len() / 2].parse::<u64>().unwrap(),
+                        stone_str[(stone_str.len() / 2)..].parse::<u64>().unwrap(),
+                    ]
+                } else {
+                    vec![stone.0 * 2024]
+                }
+            };
+            for n in new.iter() {
+                *new_stones.entry(*n).or_insert(0) += stone.1;
+            }
+        }
+        stones = new_stones;
+    }
+    Some(stones.iter().map(|x| x.1).sum())
+}
+
+pub fn part_one(input: &str) -> Option<u64> {
+    solve(input, 25)
+}
+
+pub fn part_two(input: &str) -> Option<u64> {
+    solve(input, 75)
+}
+
+#[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, Some(55312));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(65601038650482));
+    }
+}