day 2

Author: prevostc

Cargo.lock

@@ -24,8 +24,10 @@ test_lib = []
 # Template dependencies
 chrono = { version = "0.4.38", optional = true }
 dhat = { version = "0.3.3", optional = true }
+heapless = "0.8.0"
 itertools = "0.13.0"
 pico-args = "0.5.0"
+rayon = "1.10.0"
 tinyjson = "2.5.1"
 
 # Solution dependencies

Cargo.toml

@@ -6,6 +6,15 @@ 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) | `66.9µs` | `82.5µs` |
+| [Day 2](./src/bin/02.rs) | `363.4µs` | `690.8µs` |
+
+**Total: 1.20ms**
 <!--- benchmarking table --->
 
 ---

README.md

@@ -0,0 +1,6 @@
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9

data/examples/02.txt

@@ -0,0 +1,57 @@
+use heapless::Vec as HeaplessVec;
+advent_of_code::solution!(2);
+
+const MAX_LEVELS: usize = 20;
+
+fn parse_input<'a>(input: &'a str) -> impl Iterator<Item = HeaplessVec<u32, MAX_LEVELS>> + 'a {
+    input.lines().map(|line| {
+        line.split_whitespace()
+            .map(|s| s.parse::<u32>().unwrap())
+            .collect::<HeaplessVec<_, MAX_LEVELS>>()
+    })
+}
+
+#[inline]
+fn is_safe(level: &[u32]) -> bool {
+    let increasing = level.windows(2).all(|w| w[0] <= w[1]);
+    let decreasing = level.windows(2).all(|w| w[0] >= w[1]);
+    let diff = level
+        .windows(2)
+        .all(|w| w[0].abs_diff(w[1]) >= 1 && w[0].abs_diff(w[1]) <= 3);
+    (increasing || decreasing) && diff
+}
+
+pub fn part_one(input: &str) -> Option<u32> {
+    let c = parse_input(input).filter(|level| is_safe(level)).count();
+    Some(c as u32)
+}
+
+pub fn part_two(input: &str) -> Option<u32> {
+    let c = parse_input(input)
+        .filter(|level| {
+            (0..level.len()).any(|i| {
+                let mut l = level.clone();
+                l.remove(i);
+                is_safe(&l)
+            })
+        })
+        .count();
+    Some(c as u32)
+}
+
+#[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(2));
+    }
+
+    #[test]
+    fn test_part_two() {
+        let result = part_two(&advent_of_code::template::read_file("examples", DAY));
+        assert_eq!(result, Some(4));
+    }
+}