ishan/aoc2023
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day23: kind of optimized, p2 insanely slow

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This commit is contained in:
Ishan Jain 2023-12-24 03:47:59 +05:30
parent 6828455692
commit c0c1daa276
Signed by: ishan
GPG Key ID: 0506DB2A1CC75C27
2 changed files with 69 additions and 42 deletions
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68
src/day23/1.rs
View File

@ -4,36 +4,56 @@ extern crate test;
const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")]; const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
#[derive(Debug, Hash, Eq, PartialEq, Copy, Clone)]
enum Direction {
East,
West,
North,
South,
}
impl Direction {
#[inline]
const fn coords(&self) -> [([i64; 2], Self); 3] {
use Direction::*;
match self {
Direction::East => [([0, 1], East), ([1, 0], South), ([-1, 0], North)],
Direction::West => [([0, -1], West), ([1, 0], South), ([-1, 0], North)],
Direction::North => [([0, 1], East), ([0, -1], West), ([-1, 0], North)],
Direction::South => [([0, 1], East), ([0, -1], West), ([1, 0], South)],
}
}
}
fn process(data: &str) -> i64 { fn process(data: &str) -> i64 {
let mut answer = 0; let mut answer = 0;
let size = data.lines().count() as i64;
let grid: Vec<Vec<char>> = data.lines().map(|x| x.chars().collect()).collect(); let data = data.as_bytes();
let m = grid.len();
let n = grid[0].len();
let mut stack = Vec::new(); let mut stack = Vec::new();
stack.push((0, 0, 1, BitSet::<156>::new())); use Direction::*;
stack.push((0, 0, 1, BitSet::<156>::new(), South));
while let Some((distance, sx, sy, mut visited)) = stack.pop() { while let Some((distance, sx, sy, mut visited, direction)) = stack.pop() {
if sx == m as i64 - 1 && sy == n as i64 - 2 { if sx == size - 1 && sy == size - 2 {
answer = std::cmp::max(answer, distance); answer = std::cmp::max(answer, distance);
continue; continue;
} }
if visited.get(sx * m as i64 + sy) { if visited.get(sx * size + sy) {
continue; continue;
} }
visited.set(sx * m as i64 + sy); visited.set(sx * size + sy);
let c = grid[sx as usize][sy as usize]; let c = unsafe { *data.get_unchecked((sx * size + sy + sx) as usize) };
let sticky = match c { let sticky = match c {
'>' => Some([0, 1]), b'>' => Some([0, 1]),
'<' => Some([0, -1]), b'<' => Some([0, -1]),
'v' => Some([1, 0]), b'v' => Some([1, 0]),
'^' => Some([-1, 0]), b'^' => Some([-1, 0]),
_ => None, _ => None,
}; };
const DIRS: [[i64; 2]; 4] = [[0, 1], [1, 0], [0, -1], [-1, 0]];
if let Some(d) = sticky { if let Some(d) = sticky {
let mut x = sx; let mut x = sx;
let mut y = sy; let mut y = sy;
@ -44,9 +64,9 @@ fn process(data: &str) -> i64 {
if p < 0 if p < 0
|| q < 0 || q < 0
|| p >= m as i64 || p >= size
|| q >= n as i64 || q >= size
|| grid[p as usize][q as usize] != '.' || unsafe { *data.get_unchecked((p * size + q + p) as usize) } != b'.'
{ {
break; break;
} }
@ -56,21 +76,21 @@ fn process(data: &str) -> i64 {
dis += 1; dis += 1;
} }
stack.push((distance + dis, x, y, visited)); stack.push((distance + dis, x, y, visited, direction));
} else { } else {
for dir in DIRS.iter() { for (dir, direction) in direction.coords().iter() {
let a = dir[0] + sx; let a = dir[0] + sx;
let b = dir[1] + sy; let b = dir[1] + sy;
if a < 0 || b < 0 || a >= m as i64 || b >= n as i64 { if a < 0 || b < 0 || a >= size || b >= size {
continue; continue;
} }
if unsafe { grid.get_unchecked(a as usize).get_unchecked(b as usize) == &'#' } { if unsafe { *data.get_unchecked((a * size + b + a) as usize) == b'#' } {
continue; continue;
} }
stack.push((distance + 1, a, b, visited.clone())); stack.push((distance + 1, a, b, visited.clone(), *direction));
} }
} }
} }

43
src/day23/2.rs
View File

@ -3,43 +3,50 @@ extern crate test;
const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")]; const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
#[derive(Debug, Hash, Eq, PartialEq, Copy, Clone)]
enum Direction {
East,
West,
North,
South,
}
fn process(data: &str) -> i64 { fn process(data: &str) -> i64 {
let mut answer = 0; let mut answer = 0;
let grid: Vec<Vec<char>> = data.lines().map(|x| x.chars().collect()).collect(); let size = data.lines().count() as i64;
let m = grid.len() as i64; let data = data.as_bytes();
let n = grid[0].len() as i64;
use Direction::*;
let mut stack = Vec::new(); let mut stack = Vec::new();
stack.push((0, 0, 1, BitSet::<156>::new(), South));
stack.push((0, 0, 1, BitSet::<156>::new())); while let Some((distance, sx, sy, mut visited, direction)) = stack.pop() {
if sx == size - 1 && sy == size - 2 {
while let Some((distance, sx, sy, mut visited)) = stack.pop() {
if sx == m - 1 && sy == n - 2 {
answer = std::cmp::max(answer, distance); answer = std::cmp::max(answer, distance);
continue; continue;
} }
if unsafe { grid.get_unchecked(sx as usize).get_unchecked(sy as usize) == &'#' } { if unsafe { *data.get_unchecked((sx * size + sy + sx) as usize) == b'#' } {
continue; continue;
} }
if visited.get(sx * m + sy) { if visited.get(sx * size + sy) {
continue; continue;
} }
visited.set(sx * m + sy); visited.set(sx * size + sy);
if sy + 1 < n { if sy + 1 < size && direction != West {
stack.push((distance + 1, sx, sy + 1, visited.clone())); stack.push((distance + 1, sx, sy + 1, visited.clone(), East));
} }
if sy > 0 { if sy > 0 && direction != East {
stack.push((distance + 1, sx, sy - 1, visited.clone())); stack.push((distance + 1, sx, sy - 1, visited.clone(), West));
} }
if sx + 1 < n { if sx + 1 < size && direction != North {
stack.push((distance + 1, sx + 1, sy, visited.clone())); stack.push((distance + 1, sx + 1, sy, visited.clone(), South));
} }
if sx > 0 { if sx > 0 && direction != South {
stack.push((distance + 1, sx - 1, sy, visited)); stack.push((distance + 1, sx - 1, sy, visited, North));
} }
} }