rust(day17): Optimize to run in 34 ms

rust/Cargo.lock

@@ -1,56 +1,6 @@
 # This file is automatically @generated by Cargo.
 # It is not intended for manual editing.
-[[package]]
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-checksum = "7404febffaa47dac81aa44dba71523c9d069b1bdc50a77db41195149e17f68e5"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "aoc"
 version = "0.1.0"
-dependencies = [
- "regex",
-]
 
-[[package]]
-name = "lazy_static"
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-
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-
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-checksum = "38cf2c13ed4745de91a5eb834e11c00bcc3709e773173b2ce4c56c9fbde04b9c"
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- "aho-corasick",
- "memchr",
- "regex-syntax",
- "thread_local",
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-dependencies = [
- "lazy_static",
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rust/Cargo.toml

@@ -7,4 +7,3 @@ edition = "2018"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-regex = "1.4.2"

rust/src/day17.rs

@@ -1,99 +1,100 @@
 use std::time::{Duration, Instant};
 
-const SIZE: usize = 50;
+const SIZE: usize = 20;
 const OFFSET: usize = SIZE / 2;
 
-type Field = Vec<Vec<Vec<bool>>>;
+type Field = Vec<[[[bool; SIZE]; SIZE]; SIZE]>;
 
-pub fn step(field: &mut Field) {
+pub fn step(hypercube: &mut Field) {
     let mut changes = Vec::new();
-    for (z, slice) in field.iter().enumerate() {
+    for w in 0..hypercube.len() as i64 {
-        for (y, row) in slice.iter().enumerate() {
+        for z in 0..SIZE as i64 {
-            for (x, cell) in row.iter().enumerate() {
+            for y in 0..SIZE as i64 {
+                for x in 0..SIZE as i64 {
                     let mut neighbors = 0;
+                    for dw in -1..=1 {
                         for dz in -1..=1 {
                             for dy in -1..=1 {
                                 for dx in -1..=1 {
-                            let nx = dx + x as i64;
+                                    let nx = dx + x;
-                            let ny = dy + y as i64;
+                                    let ny = dy + y;
-                            let nz = dz + z as i64;
+                                    let nz = dz + z;
+                                    let nw = dw + w;
 
-                            if (nx == x as i64 && ny == y as i64 && nz == z as i64)
+                                    if !(nx == x && ny == y && nz == z && nw == w)
-                                || (nx < 0 || nx >= SIZE as i64)
+                                        && !(nx < 0 || nx >= SIZE as i64)
-                                || (ny < 0 || ny >= SIZE as i64)
+                                        && !(ny < 0 || ny >= SIZE as i64)
-                                || (nz < 0 || nz >= SIZE as i64)
+                                        && !(nz < 0 || nz >= SIZE as i64)
+                                        && !(nw < 0 || nw >= hypercube.len() as i64)
+                                        && hypercube[nw as usize][nz as usize][ny as usize]
+                                            [nx as usize]
                                     {
-                                continue;
-                            }
-
-                            if field[nz as usize][ny as usize][nx as usize] {
                                         neighbors += 1;
                                     }
                                 }
                             }
                         }
+                    }
 
-                if *cell && neighbors != 2 && neighbors != 3 {
+                    let cell = hypercube[w as usize][z as usize][y as usize][x as usize];
-                    changes.push((x, y, z, false));
+                    if cell && neighbors != 2 && neighbors != 3 {
+                        changes.push((x, y, z, w, false));
                     }
                     if !cell && neighbors == 3 {
-                    changes.push((x, y, z, true));
+                        changes.push((x, y, z, w, true));
+                    }
                 }
             }
         }
     }
 
-    for (x, y, z, state) in changes {
+    for (x, y, z, w, state) in changes {
-        field[z][y][x] = state;
+        hypercube[w as usize][z as usize][y as usize][x as usize] = state;
     }
 }
 
-pub fn run(_: bool) -> Duration {
+pub fn simulate(input: &str, n: usize) -> usize {
-    let input = std::fs::read_to_string("../inputs/17").unwrap();
+    assert!(n == 3 || n == 4);
 
-    let instant = Instant::now();
+    let w_size = if n == 3 { 1 } else { SIZE };
+    let w_offset = if n == 3 { 0 } else { OFFSET };
 
-    let mut field = vec![vec![vec![false; SIZE]; SIZE]; SIZE];
+    let mut field = vec![[[[false; SIZE]; SIZE]; SIZE]; w_size];
     for (y, line) in input.lines().enumerate() {
         for (x, cell) in line.chars().enumerate() {
-            field[OFFSET][y + OFFSET - 1][x + OFFSET - 1] = cell == '#';
+            field[w_offset][OFFSET][y + OFFSET - 2][x + OFFSET - 2] = cell == '#';
         }
     }
 
-    // for y in 0..SIZE {
+    for _ in 0..6 {
-    //     for x in 0..SIZE {
-    //         print!("{}", if field[OFFSET][y][x] { '#' } else { '.' });
-    //     }
-    //     println!();
-    // }
-
-    for i in 0..6 {
         step(&mut field);
-
-        println!("step {}:", i + 1);
-        // for z in (OFFSET - 1)..=(OFFSET + 1) {
-        //     println!("z = {}", z as i64 - OFFSET as i64);
-        //     for y in 0..SIZE {
-        //         for x in 0..SIZE {
-        //             print!("{}", if field[z][y][x] { '#' } else { '.' });
-        //         }
-        //         println!();
-        //     }
-        //     println!();
-        // }
     }
 
     let mut alive = 0;
-    for slice in field {
+    for cube in field {
+        for slice in &cube {
             for row in slice {
-            for cell in row {
+                for &cell in row {
                     if cell {
                         alive += 1;
                     }
                 }
             }
         }
-    dbg!(alive);
+    }
+    alive
+}
+
+pub fn run(print: bool) -> Duration {
+    let input = std::fs::read_to_string("../inputs/17").unwrap();
+
+    let instant = Instant::now();
+
+    let part1 = simulate(&input, 3);
+    let part2 = simulate(&input, 4);
+    if print {
+        dbg!(part1, part2);
+    }
 
     instant.elapsed()
 }