heh
| -rw-r--r-- | src/main.rs | 33 |
1 files changed, 23 insertions, 10 deletions
diff --git a/src/main.rs b/src/main.rs index f6dd4d8..7698364 100644 --- a/src/main.rs +++ b/src/main.rs @@ -28,20 +28,33 @@ )] extern crate test; pub mod util; -use rustc_hash::FxBuildHasher; pub use util::prelude::*; +struct Setz { + bits: [u128; 100], +} +impl Setz { + fn new() -> Self { + Self { bits: [0; 100] } + } + fn insert(&mut self, a: u8, b: u8) { + unsafe { *self.bits.get_unchecked_mut(a as usize) |= 1 << b }; + } + fn test(&self, a: u8, b: u8) -> bool { + unsafe { (*self.bits.get_unchecked(a as usize) & 1 << b) != 0 } + } +} #[no_mangle] pub fn run(i: &str) -> impl Display { let i = i.as_bytes(); let c = unsafe { C! { &i[..1176 * 6]}.as_chunks_unchecked::<6>() }; - let mut rules = HashSet::<[u8; 2]>::with_capacity_and_hasher(1176, FxBuildHasher::default()); + let mut bitsets = Setz::new(); for i in 0..1176 { let [a, b, _, c, d, _] = C! { c[i] }; - rules.insert([(a - b'0') * 10 + (b - b'0'), (c - b'0') * 10 + (d - b'0')]); + bitsets.insert((a - b'0') * 10 + (b - b'0'), (c - b'0') * 10 + (d - b'0')); } let mut sum = 0; - let mut v = Vec::with_capacity(20); + let mut v = Vec::with_capacity(25); 'out: for mut pages in C!(&i[1176 * 6 + 1..]).行() { v.clear(); let [a, b, rest @ ..] = pages else { @@ -56,7 +69,7 @@ pub fn run(i: &str) -> impl Display { v.push((a - b'0') * 10 + (b - b'0')); if let &[a, b] = &v[i..] { // valid ones always have a rule - if !rules.contains(&[a, b]) { + if !bitsets.test(a, b) { continue 'out; } i += 1; @@ -76,13 +89,13 @@ pub fn run(i: &str) -> impl Display { pub fn p2(i: &str) -> impl Display { let i = i.as_bytes(); let c = unsafe { C! { &i[..1176 * 6]}.as_chunks_unchecked::<6>() }; - let mut rules = HashSet::<[u8; 2]>::with_capacity_and_hasher(1176, FxBuildHasher::default()); + let mut bitsets = Setz::new(); for i in 0..1176 { let [a, b, _, c, d, _] = C! { c[i]}; - rules.insert([(a - b'0') * 10 + (b - b'0'), (c - b'0') * 10 + (d - b'0')]); + bitsets.insert((a - b'0') * 10 + (b - b'0'), (c - b'0') * 10 + (d - b'0')); } let mut sum = 0; - let mut v = Vec::with_capacity(20); + let mut v = Vec::with_capacity(25); for mut pages in C!(&i[1176 * 6 + 1..]).行() { v.clear(); let [a, b, rest @ ..] = pages else { @@ -97,7 +110,7 @@ pub fn p2(i: &str) -> impl Display { [b',', a, b, rest @ ..] => { v.push((a - b'0') * 10 + (b - b'0')); if let &[a, b] = &v[i..] { - if !rules.contains(&[a, b]) { + if !bitsets.test(a, b) { faults += 1; } i += 1; @@ -112,7 +125,7 @@ pub fn p2(i: &str) -> impl Display { } let mid = (v.len() - 1) / 2; let (_, &mut mid, _) = v.select_nth_unstable_by(mid, |&a, &b| { - if rules.contains(&[a, b]) { + if bitsets.test(a, b) { std::cmp::Ordering::Greater } else { std::cmp::Ordering::Less |