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day6 fast

This commit is contained in:
Jan-Bulthuis 2024-12-06 17:54:34 +01:00
parent 586dbbfe17
commit 02fe9aea97
3 changed files with 180 additions and 115 deletions
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52
Cargo.lock generated
View File

@ -47,10 +47,42 @@ dependencies = [
"aoc-runner",
"aoc-runner-derive",
"nom",
"rayon",
"regex",
"topological-sort",
]
[[package]]
name = "crossbeam-deque"
version = "0.8.5"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "613f8cc01fe9cf1a3eb3d7f488fd2fa8388403e97039e2f73692932e291a770d"
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 = "0.8.20"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "22ec99545bb0ed0ea7bb9b8e1e9122ea386ff8a48c0922e43f36d45ab09e0e80"
[[package]]
name = "either"
version = "1.13.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "60b1af1c220855b6ceac025d3f6ecdd2b7c4894bfe9cd9bda4fbb4bc7c0d4cf0"
[[package]]
name = "itoa"
version = "1.0.14"
@ -97,6 +129,26 @@ dependencies = [
"proc-macro2",
]
[[package]]
name = "rayon"
version = "1.10.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "b418a60154510ca1a002a752ca9714984e21e4241e804d32555251faf8b78ffa"
dependencies = [
"either",
"rayon-core",
]
[[package]]
name = "rayon-core"
version = "1.12.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
checksum = "1465873a3dfdaa8ae7cb14b4383657caab0b3e8a0aa9ae8e04b044854c8dfce2"
dependencies = [
"crossbeam-deque",
"crossbeam-utils",
]
[[package]]
name = "regex"
version = "1.11.1"

1
Cargo.toml
View File

@ -7,5 +7,6 @@ edition = "2021"
aoc-runner = "0.3.0"
aoc-runner-derive = "0.3.0"
nom = "7.1.3"
rayon = "1.10.0"
regex = "1.11.1"
topological-sort = "0.2.2"

242
src/day6.rs
View File

@ -1,29 +1,72 @@
type Input = ((usize, usize), Vec<Vec<u8>>);
use std::collections::HashSet;
use std::collections::VecDeque;
use aoc_runner_derive::{aoc, aoc_generator};
type Input = ((usize, usize), Vec<Vec<u8>>);
// type Input = ((usize, usize), Vec<Vec<u8>>, Vec<Vec<[u8; 5]>>);
const UP: u8 = 0;
const DOWN: u8 = 1;
const LEFT: u8 = 2;
const RIGHT: u8 = 4;
const EMPTY: u8 = 8;
const WALL: u8 = 16;
const PASSED: u8 = 32;
const DIR: [(isize, isize); 5] = [(0, -1), (0, 1), (-1, 0), (0, 0), (1, 0)];
const NEXT_DIR: [usize; 5] = [RIGHT as usize, LEFT as usize, UP as usize, 0, DOWN as usize];
#[aoc_generator(day6)]
fn parse(input: &str) -> Input {
let lines = input.split("\n");
let mut pos = (0, 0);
let map = lines
let mut stones = VecDeque::new();
let map: Vec<Vec<u8>> = lines
.enumerate()
.map(|(y, line)| {
line.chars()
.enumerate()
.map(|(x, c)| match c {
'.' => 0,
'#' => 1,
'.' => EMPTY,
'#' => {
stones.push_back((x, y));
WALL
}
'^' => {
pos = (x, y);
0
EMPTY
}
_ => todo!(),
})
.collect()
})
.collect();
// let mut jumps = vec![vec![[u8::MAX; 5]; map[0].len()]; map.len()];
// while let Some((x, y)) = stones.pop_front() {
// for dir in NEXT_DIR {
// let mut d = 1;
// loop {
// let pos = (x as isize - d * DIR[dir].0, y as isize - d * DIR[dir].1);
// if pos.0 < 0
// || pos.0 >= map[0].len() as isize
// || pos.1 < 0
// || pos.1 >= map.len() as isize
// || map[pos.1 as usize][pos.0 as usize] == WALL
// {
// break;
// }
// jumps[pos.1 as usize][pos.0 as usize][dir] = (d - 1) as u8;
// d += 1;
// }
// }
// }
// (pos, map, jumps)
(pos, map)
}
@ -31,161 +74,128 @@ fn parse(input: &str) -> Input {
fn part1(input: &Input) -> u64 {
let h = input.1.len();
let w = input.1[0].len();
let mut map = input.1.clone();
let mut pos = input.0;
let mut dir = (0, -1);
// let mut jumps = input.2.clone();
let mut pos = ((input.0).0 as isize, (input.0).1 as isize);
let mut dir = UP as usize;
let mut count = 0;
loop {
if map[pos.1][pos.0] == 0 {
map[pos.1][pos.0] = 2;
if map[pos.1 as usize][pos.0 as usize] == EMPTY {
count += 1;
};
if pos.0 as isize + dir.0 < 0
|| pos.0 as isize + dir.0 >= w as isize
|| pos.1 as isize + dir.1 < 0
|| pos.1 as isize + dir.1 >= h as isize
map[pos.1 as usize][pos.0 as usize] = PASSED;
}
if pos.0 + DIR[dir].0 < 0
|| pos.0 + DIR[dir].0 >= w as isize
|| pos.1 + DIR[dir].1 < 0
|| pos.1 + DIR[dir].1 >= h as isize
{
break;
}
while map[(pos.1 as isize + dir.1) as usize][(pos.0 as isize + dir.0) as usize] == 1 {
if dir.0 == 1 {
dir = (0, 1);
} else if dir.0 == -1 {
dir = (0, -1);
} else if dir.1 == 1 {
dir = (-1, 0);
} else if dir.1 == -1 {
dir = (1, 0);
while map[(pos.1 + DIR[dir].1) as usize][(pos.0 + DIR[dir].0) as usize] == WALL {
dir = NEXT_DIR[dir];
}
let next_pos = (pos.0 + DIR[dir].0, pos.1 + DIR[dir].1);
pos = next_pos;
}
pos = (
(pos.0 as isize + dir.0) as usize,
(pos.1 as isize + dir.1) as usize,
)
}
count
}
#[aoc(day6, part2)]
fn part2(input: &Input) -> u64 {
let initial = input.0;
let h = input.1.len();
let w = input.1[0].len();
let initial = ((input.0).0 as isize, (input.0).1 as isize);
let mut map = input.1.clone();
let mut pos = input.0;
let mut dir = (0, -1);
let mut loops = vec![];
let mut pos = initial;
let mut dir = UP as usize;
let mut count = 0;
loop {
if pos.0 as isize + dir.0 < 0
|| pos.0 as isize + dir.0 >= w as isize
|| pos.1 as isize + dir.1 < 0
|| pos.1 as isize + dir.1 >= h as isize
if pos.0 + DIR[dir].0 < 0
|| pos.0 + DIR[dir].0 >= w as isize
|| pos.1 + DIR[dir].1 < 0
|| pos.1 + DIR[dir].1 >= h as isize
{
break;
}
while map[(pos.1 as isize + dir.1) as usize][(pos.0 as isize + dir.0) as usize] == 1 {
if dir.0 == 1 {
dir = (0, 1);
} else if dir.0 == -1 {
dir = (0, -1);
} else if dir.1 == 1 {
dir = (-1, 0);
} else if dir.1 == -1 {
dir = (1, 0);
while map[(pos.1 + DIR[dir].1) as usize][(pos.0 + DIR[dir].0) as usize] == WALL {
dir = NEXT_DIR[dir];
}
let next_pos = (pos.0 + DIR[dir].0, pos.1 + DIR[dir].1);
if next_pos != initial && map[next_pos.1 as usize][next_pos.0 as usize] == EMPTY {
map[next_pos.1 as usize][next_pos.0 as usize] = WALL;
if check_loop(pos, dir, &mut map) {
count += 1;
}
let next_pos = (
(pos.0 as isize + dir.0) as usize,
(pos.1 as isize + dir.1) as usize,
);
if map[next_pos.1][next_pos.0] != 1 {
map[next_pos.1][next_pos.0] = 1;
if check_loop(pos, dir, &map) {
// count += 1;
if !(loops.contains(&next_pos)) && next_pos != initial {
loops.push(next_pos);
}
// println!("{} {}", nexts_pos.0 + 1, next_pos.1 + 1);
}
map[next_pos.1][next_pos.0] = 0;
map[next_pos.1 as usize][next_pos.0 as usize] = PASSED;
}
pos = next_pos;
}
loops.len() as u64
count
}
static mut VISITED: [[[bool; 4]; 130]; 130] = [[[false; 4]; 130]; 130];
static mut VISITED_VEC: Vec<(usize, usize, usize)> = vec![];
fn check_loop(pos: (usize, usize), dir: (isize, isize), map: &[Vec<u8>]) -> bool {
fn check_loop(mut pos: (isize, isize), mut dir: usize, map: &mut [Vec<u8>]) -> bool {
let h = map.len();
let w = map[0].len();
unsafe {
VISITED_VEC.clear();
VISITED_VEC.reserve(w * h * 4);
}
// let mut visited = [[[false; 4]; 130]; 130];
// let mut visited = HashSet::with_capacity(h * w * 4);
// let mut visited = 0;
let mut dir = dir;
let mut pos = pos;
let mut changed = Vec::with_capacity(w * h * 4);
loop {
if pos.0 as isize + dir.0 < 0
|| pos.0 as isize + dir.0 >= w as isize
|| pos.1 as isize + dir.1 < 0
|| pos.1 as isize + dir.1 >= h as isize
if pos.0 + DIR[dir].0 < 0
|| pos.0 + DIR[dir].0 >= w as isize
|| pos.1 + DIR[dir].1 < 0
|| pos.1 + DIR[dir].1 >= h as isize
{
break;
}
let mut turns = 0;
while map[(pos.1 as isize + dir.1) as usize][(pos.0 as isize + dir.0) as usize] == 1 {
if dir.0 == 1 {
dir = (0, 1);
} else if dir.0 == -1 {
dir = (0, -1);
} else if dir.1 == 1 {
dir = (-1, 0);
} else if dir.1 == -1 {
dir = (1, 0);
let mut turn = false;
while map[(pos.1 + DIR[dir].1) as usize][(pos.0 + DIR[dir].0) as usize] == WALL {
dir = NEXT_DIR[dir];
turn = true;
}
turns += 1;
}
if turns == 2 {
break;
}
pos = (
(pos.0 as isize + dir.0) as usize,
(pos.1 as isize + dir.1) as usize,
);
let dirnum = ((dir.1 + 1) >> 2) as usize + (dir.0 + 1) as usize;
unsafe {
if VISITED[pos.1][pos.0][dirnum] {
clear_visited();
let next_pos = (pos.0 + DIR[dir].0, pos.1 + DIR[dir].1);
if turn {
if map[next_pos.1 as usize][next_pos.0 as usize] & dir as u8 != 0 {
changed.into_iter().for_each(|pos: (isize, isize)| {
map[pos.1 as usize][pos.0 as usize] &= PASSED | WALL | EMPTY;
});
return true;
} else if turns > 0 {
VISITED[pos.1][pos.0][dirnum] = true;
VISITED_VEC.push((pos.0, pos.1, dirnum));
}
} else {
map[next_pos.1 as usize][next_pos.0 as usize] |= dir as u8;
changed.push(next_pos);
}
}
unsafe {
clear_visited();
pos = next_pos;
}
changed.into_iter().for_each(|pos: (isize, isize)| {
map[pos.1 as usize][pos.0 as usize] &= PASSED | WALL | EMPTY;
});
false
}
unsafe fn clear_visited() {
VISITED_VEC
.iter()
.for_each(|(a, b, c)| VISITED[*b][*a][*c] = false);
}
#[cfg(test)]
mod tests {
use super::*;
@ -193,10 +203,12 @@ mod tests {
#[test]
fn part1_example() {
assert_eq!(part1(&parse("....#.....\n.........#\n..........\n..#.......\n.......#..\n..........\n.#..^.....\n........#.\n#.........\n......#...")), 41);
assert_eq!(part1(&parse(include_str!("../input/2024/day6.txt"))), 4977);
}
#[test]
fn part2_example() {
assert_eq!(part2(&parse("....#.....\n.........#\n..........\n..#.......\n.......#..\n..........\n.#..^.....\n........#.\n#.........\n......#...")), 6);
assert_eq!(part2(&parse(include_str!("../input/2024/day6.txt"))), 1729);
}
}