day 24 made quicker, minor improvements

README.md

@@ -4,6 +4,6 @@ These are my solutions for [Advent of Code 2022](https://adventofcode.com/). Tha
 
 If you look at the code and see ways I could improve it, please do not hesitate to contact me. I am always grateful for everything that makes me a better programmer.
 
-Also, if you ever look for a programmer and think my code is any good, please also contact me at once.
+Also, if you ever look for a programmer and think my code is any good, please consider contacting me.
 
 All code is published under the [Unlicense](https://unlicense.org/)

src/common/direction.rs

@@ -96,35 +96,12 @@ where
     }
 }
 
-impl Add<Pos2<i32>> for Direction {
+impl Add<Direction> for Pos2<i32> {
     type Output = Pos2<i32>;
 
-    fn add(self, rhs: Pos2<i32>) -> Self::Output {
-        Pos2::add(rhs, self)
-    }
-}
-
-impl Add<Pos2<i32>> for &Direction {
-    type Output = Pos2<i32>;
-
-    fn add(self, rhs: Pos2<i32>) -> Self::Output {
-        Pos2::add(rhs, *self)
-    }
-}
-
-impl Add<&Pos2<i32>> for Direction {
-    type Output = Pos2<i32>;
-
-    fn add(self, rhs: &Pos2<i32>) -> Self::Output {
-        Pos2::add(*rhs, self)
-    }
-}
-
-impl Add<&Pos2<i32>> for &Direction {
-    type Output = Pos2<i32>;
-
-    fn add(self, rhs: &Pos2<i32>) -> Self::Output {
-        Pos2::add(*rhs, *self)
+    fn add(self, rhs: Direction) -> Self::Output {
+        let rhs: Pos2<i32> = rhs.into();
+        self + rhs
     }
 }
 
@@ -135,27 +112,3 @@ impl Add<Turn> for Direction {
         self.turn(rhs)
     }
 }
-
-impl Add<&Turn> for Direction {
-    type Output = Self;
-
-    fn add(self, rhs: &Turn) -> Direction {
-        Direction::add(self, *rhs)
-    }
-}
-
-impl Add<Turn> for &Direction {
-    type Output = Direction;
-
-    fn add(self, rhs: Turn) -> Direction {
-        Direction::add(*self, rhs)
-    }
-}
-
-impl Add<&Turn> for &Direction {
-    type Output = Direction;
-
-    fn add(self, rhs: &Turn) -> Direction {
-        Direction::add(*self, *rhs)
-    }
-}

src/common/pos2.rs

@@ -1,3 +1,5 @@
+#![allow(dead_code)]
+
 use super::direction::Direction;
 use super::{abs::Abs, math::gcd};
 use num_traits::{CheckedAdd, CheckedSub, Float, Num, NumCast, Signed, Zero};
@@ -157,17 +159,27 @@ where
     }
 }
 
-impl<T, P: Into<Pos2<T>>> Add<P> for Pos2<T>
+impl<T> Add for Pos2<T>
 where
     T: Num + Copy,
 {
     type Output = Self;
-    fn add(self, rhs: P) -> Self::Output {
-        let rhs = rhs.into();
+
+    fn add(self, rhs: Self) -> Self::Output {
         Pos2::new(self.x() + rhs.x(), self.y() + rhs.y())
     }
 }
 
+impl<T> Add<(T, T)> for Pos2<T>
+where
+    T: Num + Copy,
+{
+    type Output = Self;
+    fn add(self, rhs: (T, T)) -> Self::Output {
+        Pos2::new(self.x() + rhs.0, self.y() + rhs.1)
+    }
+}
+
 impl<T, P: Into<Pos2<T>>> AddAssign<P> for Pos2<T>
 where
     T: AddAssign<T> + Copy,

src/common/unit_vector.rs

@@ -14,11 +14,7 @@ pub const NEG_Z: UnitVector = UnitVector(Pos3::new(0, 0, -1));
 
 impl UnitVector {
     pub fn new(vector: Pos3<i8>) -> Option<Self> {
-        if vector.is_unit() {
-            Some(UnitVector(vector))
-        } else {
-            None
-        }
+        vector.is_unit().then(|| UnitVector(vector))
     }
 
     pub fn x(self) -> i8 {

src/days/day24/mod.rs

@@ -1,12 +1,7 @@
-use std::{
-    collections::{BinaryHeap, HashSet},
-    str::FromStr,
-};
-
-use crate::common::{direction::Direction, file::split_lines, math::lcm, pos2::Pos2};
-
 use super::template::{DayTrait, ResultType};
+use crate::common::{direction::Direction, file::split_lines, math::lcm, pos2::Pos2};
 use itertools::Itertools;
+use std::{collections::HashSet, str::FromStr};
 use thiserror::Error;
 
 const DAY_NUMBER: usize = 24;
@@ -74,7 +69,7 @@ struct Valley {
     storm: Storm,
 }
 
-#[derive(Debug)]
+#[derive(Debug, PartialEq, Eq)]
 struct State {
     time: Time,
     trip: Trip,
@@ -83,57 +78,28 @@ struct State {
     target: Pos2<usize>,
 }
 
-impl Eq for State {}
-
-impl PartialEq for State {
-    fn eq(&self, other: &Self) -> bool {
-        self.time == other.time
-    }
-}
-
-impl PartialOrd for State {
-    fn partial_cmp(&self, other: &Self) -> Option<std::cmp::Ordering> {
-        Some(self.cmp(&other))
-    }
-}
-
-impl Ord for State {
-    fn cmp(&self, other: &Self) -> std::cmp::Ordering {
-        self.time.cmp(&other.time).reverse()
-    }
-}
-
 impl State {
-    fn new(start: Pos2<usize>, target: Pos2<usize>) -> Self {
+    fn new(entry: Pos2<usize>, exit: Pos2<usize>) -> Self {
         Self {
             time: Time(0),
             trip: Trip(0),
-            position: start,
-            start,
-            target,
+            position: entry,
+            start: entry,
+            target: exit,
         }
     }
 
-    fn wait(&self) -> Self {
+    fn hit_target(&self) -> Self {
         Self {
             time: self.time.inc(),
-            trip: self.trip,
-            position: self.position,
-            start: self.start,
-            target: self.target,
+            trip: self.trip.inc(),
+            position: self.target,
+            start: self.target,
+            target: self.start,
         }
     }
 
     fn walk_to(&self, position: Pos2<usize>) -> Self {
-        if position == self.target {
-            Self {
-                time: self.time.inc(),
-                trip: self.trip.inc(),
-                position,
-                start: self.target,
-                target: self.start,
-            }
-        } else {
         Self {
             time: self.time.inc(),
             trip: self.trip,
@@ -142,25 +108,24 @@ impl State {
             target: self.target,
         }
     }
-    }
 
     fn next_states(&self, valley: &Valley) -> Vec<State> {
         let frame = valley.storm.get(self.time.inc());
 
-        let mut states = Vec::new();
+        let mut states = Vec::with_capacity(4);
         let mut dir = Direction::East;
         for _ in 0..4 {
             if let Some(next_pos) = self.position.check_add(dir) {
-                if frame.is_empty(&next_pos) || next_pos == self.target {
-                    states.push(self.walk_to(next_pos))
+                if next_pos == self.target {
+                    states.push(self.hit_target());
+                } else if frame.is_accessible(&next_pos) {
+                    states.push(self.walk_to(next_pos));
                 }
             }
             dir = dir.turn_left();
         }
-        if frame.is_empty(&self.position)
-            || (states.is_empty() && (self.position == self.target || self.position == self.start))
-        {
-            states.push(self.wait());
+        if frame.is_accessible(&self.position) || self.position == self.start {
+            states.push(self.walk_to(self.position));
         }
         states
     }
@@ -237,29 +202,26 @@ impl Valley {
     }
 
     fn cross(&self, trips: Trip) -> Result<usize, BlizzardError> {
-        let start = State::new(self.get_entry(), self.get_exit());
-        let mut queue = BinaryHeap::new();
-        queue.push(start);
         let mut seen = HashSet::new();
-        let mut advanced = Trip(0);
 
+        let start = State::new(self.get_entry(), self.get_exit());
+        let mut queue = vec![start];
+        let mut next_queue = vec![];
         while let Some(current) = queue.pop() {
-            if current.trip == trips {
-                return Ok(current.time.get());
-            }
-            if advanced > current.trip.inc() {
-                continue;
-            }
-            advanced = advanced.max(current.trip);
-
-            let normalized_time = self.normalize_time(current.time);
-            let fingerprint = (normalized_time, current.trip, current.position);
-            if seen.contains(&fingerprint) {
-                continue;
+            for next_state in current.next_states(&self) {
+                if next_state.trip == trips {
+                    return Ok(next_state.time.get());
                 }
+                let fingerprint = (next_state.position, next_state.trip);
+                if !seen.contains(&fingerprint) {
                     seen.insert(fingerprint);
-
-            queue.extend(current.next_states(&self));
+                    next_queue.push(next_state);
+                }
+            }
+            if queue.is_empty() {
+                std::mem::swap(&mut queue, &mut next_queue);
+                seen.clear();
+            }
         }
         Err(BlizzardError::NoPathFound)
     }
@@ -270,10 +232,6 @@ impl Valley {
     fn get_exit(&self) -> Pos2<usize> {
         Pos2::new(self.exit, self.height + 1)
     }
-
-    fn normalize_time(&self, time: Time) -> Time {
-        Time(time.get() % self.storm.len())
-    }
 }
 
 impl FromStr for Valley {
@@ -388,7 +346,7 @@ impl Blizzards {
 struct Frame(Vec<Vec<bool>>);
 
 impl Frame {
-    fn is_empty(&self, pos: &Pos2<usize>) -> bool {
+    fn is_accessible(&self, pos: &Pos2<usize>) -> bool {
         if pos.y() == 0 {
             false
         } else {
@@ -405,23 +363,20 @@ struct Storm(Vec<Frame>);
 
 impl Storm {
     fn new(blizzards: Blizzards) -> Self {
-        let mut storm = Vec::with_capacity(blizzards.period);
-        for time in 0..blizzards.period {
-            storm.push(blizzards.frame_at_time(time));
-        }
+        let storm = (0..blizzards.period)
+            .map(|time| blizzards.frame_at_time(time))
+            .collect_vec();
         Self(storm)
     }
 
     #[inline]
-    #[allow(dead_code)]
     pub fn len(&self) -> usize {
         self.0.len()
     }
 
     #[inline]
     pub fn get(&self, time: Time) -> &Frame {
-        let index = time.get() % self.0.len();
-        &self.0[index]
+        &self.0[time.get() % self.len()]
     }
 }
 
@@ -465,7 +420,10 @@ mod test {
         assert_eq!(valley.storm.len(), 5);
         assert_eq!(valley.get_entry(), Pos2::new(0, 0));
         assert_eq!(valley.get_exit(), Pos2::new(4, 6));
-        assert_eq!(valley.storm.get(Time(3)).is_empty(&Pos2::new(3, 2)), false);
+        assert_eq!(
+            valley.storm.get(Time(3)).is_accessible(&Pos2::new(3, 2)),
+            false
+        );
 
         Ok(())
     }
@@ -506,16 +464,7 @@ mod test {
             start: Pos2::new(0, 0),
             target: Pos2::new(5, 5),
         };
-        let mut next_states = position.next_states(&valley);
-        next_states.sort();
         let expected = vec![
-            State {
-                time: Time(18),
-                trip: Trip(1),
-                position: Pos2::new(5, 5),
-                start: Pos2::new(5, 5),
-                target: Pos2::new(0, 0),
-            },
             State {
                 time: Time(18),
                 trip: Trip(0),
@@ -523,7 +472,15 @@ mod test {
                 start: Pos2::new(0, 0),
                 target: Pos2::new(5, 5),
             },
+            State {
+                time: Time(18),
+                trip: Trip(1),
+                position: Pos2::new(5, 5),
+                start: Pos2::new(5, 5),
+                target: Pos2::new(0, 0),
+            },
         ];
+        let next_states = position.next_states(&valley);
         assert_eq!(next_states, expected);
         Ok(())
     }

src/days/day25/mod.rs

@@ -31,12 +31,11 @@ impl DayTrait for Day {
 
 impl Snafu {
     pub fn as_str(&self) -> String {
-        let value = self.0;
-        if value == 0 {
+        if self.0 == 0 {
             return String::from("0");
         }
 
-        unfold(value, |value| {
+        unfold(self.0, |value| {
             if *value == 0 {
                 return None;
             }
@@ -46,7 +45,7 @@ impl Snafu {
         })
         .map(|digit| "=-012".chars().nth(digit).unwrap())
         .collect_vec()
-        .iter()
+        .into_iter()
         .rev()
         .join("")
     }