multiple: Use FxHashMap for s p e e d

src/day1.rs

@@ -1,7 +1,9 @@
 use aoc_runner_derive::{aoc, aoc_generator};
-use std::collections::HashMap;
+use rustc_hash::FxHashMap;
 use std::io::{BufRead, Lines};
 
+type HashMap<K, V> = FxHashMap<K, V>;
+
 #[aoc_generator(day1)]
 pub fn get_input(input: &[u8]) -> Locations {
     Locations::from(input.lines())
@@ -32,7 +34,7 @@ impl Locations {
         self.right.sort();
     }
     fn right_count(&self) -> HashMap<u64, u64> {
-        let mut right_count: HashMap<u64, u64> = HashMap::new();
+        let mut right_count: HashMap<u64, u64> = HashMap::default();
         for rval in &self.right {
             right_count.insert(*rval, *right_count.get(rval).unwrap_or(&0) + 1);
         }

src/day11.rs

@@ -1,10 +1,10 @@
 use aoc_runner_derive::aoc;
 use itertools::Itertools;
-use std::collections::HashMap;
+use rustc_hash::FxHashMap;
 use std::iter::repeat;
 
 type IntType = u64;
-type CacheType = HashMap<Stone, IntType>;
+type CacheType = FxHashMap<Stone, IntType>;
 
 #[derive(Clone, Debug, Hash, PartialEq, Eq)]
 struct Stone(IntType);
@@ -66,7 +66,7 @@ fn count_blinks(stone: &Stone, blink: usize, cache: &mut Vec<CacheType>) -> IntT
 }
 
 fn blink_stones(stones: Stones, blinks: usize) -> IntType {
-    let mut cache = Vec::from_iter(repeat(CacheType::new()).take(blinks));
+    let mut cache = Vec::from_iter(repeat(CacheType::default()).take(blinks));
     stones
         .0
         .iter()

src/day8.rs

@@ -1,9 +1,11 @@
 use aoc_runner_derive::{aoc, aoc_generator};
 use grid::Grid;
 use itertools::Itertools;
-use std::collections::HashSet;
+use rustc_hash::FxHashSet;
 use std::io::BufRead;
 
+type HashSet<T> = FxHashSet<T>;
+
 #[aoc_generator(day8)]
 pub fn get_input(input: &[u8]) -> AntennaMap {
     AntennaMap::from(input)