ringofstorms/advent_of_code
ringofstorms/advent_of_code
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Merge branch 'master' of github.com:RingOfStorms/advent_of_code_2023

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This commit is contained in:
RingOfStorms (Joshua Bell) 2023-12-05 04:35:27 -06:00
commit 71d8241b43
1 changed files with 14 additions and 11 deletions
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25
src/bin/day4.rs
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@ -6,11 +6,12 @@ use std::{
time::Instant, time::Instant,
}; };
#[derive(Debug)] #[derive(Debug, Eq, PartialEq, Hash, Clone)]
struct Card { struct Card {
id: usize, id: usize,
part_2_matches: usize,
part_1_score: usize, part_1_score: usize,
part_2_matches: usize,
part_2_count: usize,
} }
impl FromStr for Card { impl FromStr for Card {
@ -56,6 +57,7 @@ impl FromStr for Card {
id: id.ok_or("no id found")?, id: id.ok_or("no id found")?,
part_1_score: score, part_1_score: score,
part_2_matches: matches, part_2_matches: matches,
part_2_count: 1,
}) })
} }
} }
@ -87,20 +89,21 @@ fn part2(input: String) -> Result<usize> {
fn part2_revised(input: String) -> Result<usize> { fn part2_revised(input: String) -> Result<usize> {
let mut sum = 0; let mut sum = 0;
let cards = input let mut cards = input
.lines() .lines()
.map(|line| line.parse::<Card>()) .map(|line| line.parse::<Card>())
.filter_map(|card| card.ok()) .filter_map(|card| card.ok())
.collect_vec(); .collect_vec();
let mut card_counts: HashMap<usize, usize> = HashMap::new(); for i in 0..cards.len() {
for card in cards { let (count, matches) = {
let count = { let card = cards.get(i).ok_or("card not found")?;
let card_count = card_counts.entry(card.id).or_insert(1); sum += card.part_2_count;
sum += *card_count; (card.part_2_count, card.part_2_matches)
*card_count
}; };
for card_index in 1..=card.part_2_matches { for card_index in 1..=matches {
*card_counts.entry(card.id + card_index).or_insert(1) += count; cards.get_mut(i + card_index).map(|card_below| {
card_below.part_2_count += count;
});
} }
} }
Ok(sum) Ok(sum)