Added hashbrown

aoc_2024/src/day8.rs

@@ -1,4 +1,4 @@
-use std::collections::{HashMap, HashSet};
+use hashbrown::{HashMap, HashSet};
 
 use aoc_runner_derive::{aoc, aoc_generator};
 use num::integer::gcd;
@@ -15,11 +15,9 @@ fn parse(input: &str) -> Input {
             .enumerate()
             .filter(|(_, c)| c != &'.')
             .for_each(|(x, c)| {
-                if let std::collections::hash_map::Entry::Vacant(e) = map.entry(c) {
-                    e.insert(vec![(x as isize, y as isize)]);
-                } else {
-                    map.get_mut(&c).unwrap().push((x as isize, y as isize));
-                }
+                map.entry(c)
+                    .or_insert(Vec::new())
+                    .push((x as isize, y as isize));
             });
     });
     let vec = map.into_values().collect();
@@ -28,7 +26,7 @@ fn parse(input: &str) -> Input {
 
 #[aoc(day8, part1)]
 fn part1(input: &Input) -> usize {
-    let mut set = HashSet::with_capacity(input.1.len() * input.1.len());
+    let mut set = HashSet::new();
     input.1.iter().for_each(|vec| {
         for l in 0..vec.len() {
             for r in l + 1..vec.len() {
@@ -58,7 +56,6 @@ fn part2(input: &Input) -> usize {
                 let a2 = vec[r];
                 let s = a1;
                 let v = (a2.0 - a1.0, a2.1 - a1.1);
-                let v = (v.0 / gcd(v.0, v.1), v.1 / gcd(v.0, v.1));
                 let mut d = 0;
                 loop {
                     let c = (s.0 + d * v.0, s.1 + d * v.1);
@@ -82,12 +79,6 @@ fn part2(input: &Input) -> usize {
             }
         }
     });
-    // for y in 0..input.0 .1 {
-    //     println!();
-    //     for x in 0..input.0 .0 {
-    //         print!("{}", if set.contains(&(x, y)) { '#' } else { '.' })
-    //     }
-    // }
     set.len()
 }
 
@@ -113,5 +104,7 @@ mod tests {
             )),
             34
         );
+
+        assert_eq!(part2(&parse(include_str!("../input/2024/day8.txt"))), 1017);
     }
 }