kageru/advent-of-code
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some cleanup

This commit is contained in:
kageru 2023-12-07 13:36:19 +01:00
parent e18f10cb4f
commit b430bfb69a
1 changed files with 11 additions and 27 deletions
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38
2023/src/bin/day07.rs
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@ -9,8 +9,7 @@ type I = usize;
type Hand = [u8; 5];
type Parsed = Vec<(Hand, I)>;
const CARDS: [u8; 13] = [b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b'T', b'J', b'Q', b'K', b'A'];
const CARDS_P2: [u8; 13] = [b'J', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b'T', b'Q', b'K', b'A'];
const CARDS: [u8; 14] = [b' ', b'2', b'3', b'4', b'5', b'6', b'7', b'8', b'9', b'T', b'J', b'Q', b'K', b'A'];
#[derive(Debug, PartialEq)]
enum Quality {
@ -45,37 +44,29 @@ fn parse_input(raw: &str) -> Parsed {
fn rate_hand(mut hand: Hand) -> Quality {
hand.sort();
let paired = hand
let equals = hand
.into_iter()
.map(|c| (c, 1))
.coalesce(|(c1, n1), (c2, n2)| if c1 == c2 { Ok((c1, n1 + n2)) } else { Err(((c1, n1), (c2, n2))) })
.map(|(_, n)| n)
.collect_vec();
match paired.as_slice() {
match equals.as_slice() {
[_] => Quality::AllEqual,
[4, 1] | [1, 4] => Quality::Quad,
[3, 2] | [2, 3] => Quality::FullHouse,
a @ [_, _, _] if a.contains(&3) => Quality::Triple,
[3, 1, 1] | [1, 3, 1] | [1, 1, 3] => Quality::Triple,
[_, _, _] => Quality::TwoPair,
[_, _, _, _] => Quality::Pair,
_ => Quality::None,
}
}
fn tiebreaker(hand: &Hand, values: &[u8; 13]) -> usize {
let tiebreak_hand = hand.map(|b| values.iter().position(|&c| c == b).unwrap());
tiebreak_hand.iter().fold(0, |acc, n| (acc << 4) + n)
fn tiebreak(hand: &Hand) -> usize {
hand.iter().map(|b| CARDS.iter().position(|c| c == b).unwrap_or(0)).fold(0, |acc, n| (acc << 4) + n)
}
fn part1(hands: &Parsed) -> usize {
let mut rated_hands = hands
.iter()
.cloned()
.map(|(hand, points)| {
let tiebreak = tiebreaker(&hand, &CARDS);
(rate_hand(hand) as usize + tiebreak, points)
})
.collect_vec();
let mut rated_hands = hands.iter().cloned().map(|(hand, points)| (tiebreak(&hand) + rate_hand(hand) as usize, points)).collect_vec();
rated_hands.sort_unstable_by_key(|(v, _)| *v);
rated_hands.into_iter().zip(1..).map(|((_, points), position)| points * position).sum()
}
@ -85,17 +76,10 @@ fn part2(hands: &Parsed) -> usize {
.iter()
.cloned()
.map(|(mut hand, points)| {
let tiebreak = tiebreaker(&hand, &CARDS_P2);
// Count how many jokers there are and insert nonsense data for them so they can’t produce any pairs.
let mut jokers = 0;
for c in hand.iter_mut().filter(|c| c == &&b'J') {
*c = jokers;
jokers += 1;
}
let mut rating = rate_hand(hand);
for _ in 0..jokers {
rating = rating.upgrade();
}
let jokers = hand.iter_mut().filter(|c| c == &&b'J').zip(0..).map(|(c, i)| *c = i).count();
let tiebreak = tiebreak(&hand);
let rating = (0..jokers).fold(rate_hand(hand), |rating, _| rating.upgrade());
(rating as usize + tiebreak, points)
})
.collect_vec();
@ -127,7 +111,7 @@ mod bench {
#[bench]
fn bench_tiebreak(b: &mut test::Bencher) {
b.iter(|| assert_eq!(tiebreaker(black_box(&[b'3', b'2', b'T', b'3', b'K']), &CARDS), 67611))
b.iter(|| assert_eq!(tiebreak(black_box(&[b'3', b'2', b'T', b'3', b'K'])), 137516))
}
#[bench]