Optimize 09

Cargo.lock

@@ -32,9 +32,9 @@ version = "0.0.0"
 dependencies = [
  "anyhow",
  "cached",
- "derive_more",
  "glam",
  "itertools",
+ "rayon",
 ]
 
 [[package]]
@@ -82,6 +82,31 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "crossbeam-deque"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9dd111b7b7f7d55b72c0a6ae361660ee5853c9af73f70c3c2ef6858b950e2e51"
+dependencies = [
+ "crossbeam-epoch",
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-epoch"
+version = "0.9.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5b82ac4a3c2ca9c3460964f020e1402edd5753411d7737aa39c3714ad1b5420e"
+dependencies = [
+ "crossbeam-utils",
+]
+
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
+
 [[package]]
 name = "darling"
 version = "0.20.11"
@@ -117,27 +142,6 @@ dependencies = [
  "syn",
 ]
 
-[[package]]
-name = "derive_more"
-version = "2.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "10b768e943bed7bf2cab53df09f4bc34bfd217cdb57d971e769874c9a6710618"
-dependencies = [
- "derive_more-impl",
-]
-
-[[package]]
-name = "derive_more-impl"
-version = "2.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6d286bfdaf75e988b4a78e013ecd79c581e06399ab53fbacd2d916c2f904f30b"
-dependencies = [
- "proc-macro2",
- "quote",
- "rustc_version",
- "syn",
-]
-
 [[package]]
 name = "either"
 version = "1.13.0"
@@ -229,12 +233,23 @@ dependencies = [
 ]
 
 [[package]]
-name = "rustc_version"
+name = "rayon"
-version = "0.4.1"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfcb3a22ef46e85b45de6ee7e79d063319ebb6594faafcf1c225ea92ab6e9b92"
+checksum = "368f01d005bf8fd9b1206fb6fa653e6c4a81ceb1466406b81792d87c5677a58f"
 dependencies = [
- "semver",
+ "either",
+ "rayon-core",
+]
+
+[[package]]
+name = "rayon-core"
+version = "1.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "22e18b0f0062d30d4230b2e85ff77fdfe4326feb054b9783a3460d8435c8ab91"
+dependencies = [
+ "crossbeam-deque",
+ "crossbeam-utils",
 ]
 
 [[package]]
@@ -243,12 +258,6 @@ version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b39cdef0fa800fc44525c84ccb54a029961a8215f9619753635a9c0d2538d46d"
 
-[[package]]
-name = "semver"
-version = "1.0.27"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d767eb0aabc880b29956c35734170f26ed551a859dbd361d140cdbeca61ab1e2"
-
 [[package]]
 name = "strsim"
 version = "0.11.1"

Cargo.toml

@@ -6,9 +6,9 @@ edition = "2021"
 [dependencies]
 anyhow = "1.0.100"
 cached = "0.56.0"
-derive_more = { version = "2.1.0", features = ["deref"] }
 glam = "0.30.9"
 itertools = "0.14.0"
+rayon = "1.11.0"
 
 [profile.release]
 debug = true

src/bin/09.rs

@@ -1,8 +1,7 @@
 use aoc::*;
-use derive_more::Deref;
 use glam::I64Vec2;
 use itertools::Itertools;
-use std::cmp::Reverse;
+use rayon::prelude::*;
 use std::collections::HashMap;
 
 const INPUT: &str = include_str!("../../input/09");
@@ -45,19 +44,19 @@ fn part2(input: &str) -> u64 {
         .iter()
         .copied()
         .tuple_combinations()
+        .par_bridge()
         .map(Rect::from)
-        .sorted_by_key(|r| {
+        .filter(|&r| polygon.contains_rect(r))
-            let area = r.uncompress(&uncompress).area();
+        .map(|r| r.uncompress(&uncompress).area())
-            Reverse(area)
+        .max()
-        })
-        .find(|&r| polygon.contains_rect(r))
         .unwrap()
-        .uncompress(&uncompress)
-        .area()
 }
 
 struct Polygon {
     points: Vec<I64Vec2>,
+    /// Contains vertical lines sorted by their x value in ascending order.
+    /// This is important for contains_point, as that assumes the lines are in this order.
+    /// This dramatically speeds up the raycast in contains_point, as the ray is cast in positive x direction.
     cached_vertical_lines: Vec<Line>,
 }
 
@@ -72,7 +71,7 @@ impl Polygon {
     fn parse(input: &str) -> Self {
         let mut polygon = Self {
             points: input.lines().map(parse_line).collect(),
-            cached_vertical_lines: vec![],
+            cached_vertical_lines: Default::default(),
         };
         polygon.cache_vertical_lines();
         polygon
@@ -127,19 +126,20 @@ impl Polygon {
         let xs = self
             .cached_vertical_lines
             .iter()
+            .take_while(|line| line.0.x < p.x)
             .filter(|l| {
                 let ymin = l.0.y.min(l.1.y);
                 let ymax = l.0.y.max(l.1.y);
                 ymin <= p.y && p.y <= ymax
             })
-            .flat_map(|l| [l.0.x])
+            .map(|l| l.0.x)
-            .filter(|&x| x < p.x)
             .chain([p.x])
             .sorted();
 
-        let line = |p| {
+        let line_with = |p: I64Vec2| {
             self.cached_vertical_lines
                 .iter()
+                .take_while(|line| line.0.x <= p.x)
                 .find(|line| line.contains(p))
                 .copied()
         };
@@ -149,7 +149,7 @@ impl Polygon {
 
         for x in xs {
             let check = I64Vec2::new(x, p.y);
-            if let Some(line) = line(check) {
+            if let Some(line) = line_with(check) {
                 winding = line.winding();
                 on_line = true;
             } else {
@@ -160,19 +160,17 @@ impl Polygon {
         winding < 0 || on_line
     }
 
-    fn vertical_lines(&self) -> Vec<Line> {
+    fn cache_vertical_lines(&mut self) {
-        self.points
+        self.cached_vertical_lines = self
+            .points
             .iter()
             .chain(self.points.first()) // close the loop
             .copied()
             .tuple_windows()
             .map(|(a, b)| Line(a, b))
             .filter(|l| l.is_vertical())
-            .collect()
+            .sorted_by_key(|line| line.0.x)
-    }
+            .collect();
-
-    fn cache_vertical_lines(&mut self) {
-        self.cached_vertical_lines = self.vertical_lines();
     }
 }