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day 8 part 2

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This commit is contained in:
Andy Teijelo 2023-12-08 21:28:10 -05:00
parent adda315684
commit 5167305a7a
5 changed files with 911 additions and 1104 deletions
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14
example.txt
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@ -1,5 +1,9 @@
32T3K 765
T55J5 684
KK677 28
KTJJT 220
QQQJA 483
RL
AAA = (BBB, CCC)
BBB = (DDD, EEE)
CCC = (ZZZ, GGG)
DDD = (DDD, DDD)
EEE = (EEE, EEE)
GGG = (GGG, GGG)
ZZZ = (ZZZ, ZZZ)

5
example2.txt Normal file
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@ -0,0 +1,5 @@
LLR
AAA = (BBB, BBB)
BBB = (AAA, ZZZ)
ZZZ = (ZZZ, ZZZ)

10
example3.txt Normal file
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@ -0,0 +1,10 @@
LR
11A = (11B, XXX)
11B = (XXX, 11Z)
11Z = (11B, XXX)
22A = (22B, XXX)
22B = (22C, 22C)
22C = (22Z, 22Z)
22Z = (22B, 22B)
XXX = (XXX, XXX)

1792
input.txt
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File diff suppressed because it is too large Load diff

192
src/main.rs
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@ -1,119 +1,115 @@
use std::{collections::HashMap, io::stdin};
use std::{
cmp::{max, min},
collections::HashMap,
io::stdin,
};
use anyhow::{bail, Result};
use counter::Counter;
use anyhow::Result;
use regex::Regex;
#[derive(Debug, PartialEq, Eq, Hash)]
enum HandType {
FiveOfAKind,
FourOfAKind,
FullHouse,
ThreeOfAKind,
TwoPair,
OnePair,
HighCard,
// RL
//
// AAA = (BBB, CCC)
// BBB = (DDD, EEE)
// CCC = (ZZZ, GGG)
// DDD = (DDD, DDD)
// EEE = (EEE, EEE)
// GGG = (GGG, GGG)
// ZZZ = (ZZZ, ZZZ)
fn gcd(a: i64, b: i64) -> i64 {
let mut l = max(a, b);
let mut s = min(a, b);
loop {
let r = l % s;
l = s;
s = r;
if r == 0 {
break;
}
}
l
}
fn hand_type(hand: &str) -> HandType {
let counter_without_joker: Counter<char> = hand.chars().filter(|c| *c != 'J').collect();
if counter_without_joker.is_empty() {
// it's JJJJJ
return HandType::FiveOfAKind;
}
let hand = hand.replace(
'J',
&counter_without_joker
.k_most_common_ordered(1)
.first()
.unwrap()
.0
.to_string(),
);
let counter: Counter<char> = hand.chars().collect();
if counter.keys().len() == 1 {
return HandType::FiveOfAKind;
}
if counter.keys().len() == 2 {
if counter.k_most_common_ordered(1)[0].1 == 4 {
return HandType::FourOfAKind;
}
if counter.k_most_common_ordered(1)[0].1 == 3 {
return HandType::FullHouse;
}
}
if counter.keys().len() == 3 {
if counter.k_most_common_ordered(1)[0].1 == 3 {
return HandType::ThreeOfAKind;
}
if counter.k_most_common_ordered(1)[0].1 == 2 {
return HandType::TwoPair;
}
}
if counter.keys().len() == 4 {
return HandType::OnePair;
}
HandType::HighCard
}
type CmpKey = (u8, u8, u8, u8, u8, u8);
fn hand_cmp_key(hand: &str) -> CmpKey {
let hand_strength = HashMap::from([
(HandType::FiveOfAKind, 7u8),
(HandType::FourOfAKind, 6u8),
(HandType::FullHouse, 5u8),
(HandType::ThreeOfAKind, 4u8),
(HandType::TwoPair, 3u8),
(HandType::OnePair, 2u8),
(HandType::HighCard, 1u8),
]);
let card_strength: HashMap<char, u8> = "AKQT98765432J"
.chars()
.enumerate()
.map(|(i, c)| (c, (14 - i) as u8))
.collect();
let mut r = vec![*hand_strength.get(&hand_type(hand)).unwrap()];
r.extend(hand.chars().map(|c| card_strength.get(&c).unwrap()));
(r[0], r[1], r[2], r[3], r[4], r[5])
fn lcm(a: i64, b: i64) -> i64 {
a * b / gcd(a, b)
}
fn main() -> Result<()> {
let mut bids = vec![];
let nodes_re = Regex::new(r"([0-9A-Z]{3}) = \(([0-9A-Z]{3}), ([0-9A-Z]{3})\)")?;
let mut nodes_map = HashMap::new();
let mut first = true;
let mut instructions = "".to_string();
for line in stdin().lines().map_while(Result::ok) {
let parts: Vec<&str> = line.split_whitespace().collect();
let hand = parts[0];
let bid: i64 = parts[1].parse().unwrap();
println!("{} {:?} {}", hand, hand_type(hand), bid);
if first {
instructions = line.clone();
first = false;
}
for m in nodes_re.captures_iter(&line) {
nodes_map.insert(
m.get(1).unwrap().as_str().to_string(),
(
m.get(2).unwrap().as_str().to_string(),
m.get(3).unwrap().as_str().to_string(),
),
);
}
}
bids.push((hand.to_owned(), bid));
let mut cursors: Vec<String> = nodes_map
.keys()
.filter(|n| n.ends_with('A'))
.cloned()
.collect();
println!("starting cursors: {:?}", cursors);
// by inspecting the input, we know that the distance from A - Z is
// equal to the size of the Z - Z loops for all ghosts
// so we just need to save those and do LCM for all
//
// honestly, I'm a bit disappointed because of this
let mut loop_lengths = vec![];
for cursor in cursors.iter_mut() {
let mut steps = 0;
// let mut zeds = HashSet::new();
println!("cursor {cursor:?}:");
'outer: loop {
for instruction in instructions.chars() {
match instruction {
'L' => *cursor = nodes_map.get(cursor).unwrap().0.clone(),
'R' => *cursor = nodes_map.get(cursor).unwrap().1.clone(),
_ => {}
}
bids.sort_by_key(|(hand, _)| hand_cmp_key(hand));
let mut winnings = 0;
for (i, b) in bids.iter().enumerate() {
let (_, bid) = b;
winnings += (i as i64 + 1) * bid;
// println!("after going {} cursors are {:?}", instructions, cursors);
steps += 1;
// if cursors.iter().all(|c| c.ends_with('Z')) {
if cursor.ends_with('Z') {
loop_lengths.push(steps);
break 'outer;
// if zeds.contains(cursor) {
// println!(" looped on {cursor} at {steps} steps");
// break 'outer;
// }
//
// println!(" found {cursor} at {steps} steps");
// zeds.insert(cursor.clone());
}
println!("{}", winnings);
}
}
}
let result = loop_lengths.into_iter().fold(1i64, lcm);
println!("{result}");
Ok(())
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_hand_types() {}
#[test]
fn test_hand_types() {
assert_eq!(hand_type("AAAAJ"), HandType::FiveOfAKind);
assert_eq!(hand_type("AAAJJ"), HandType::FiveOfAKind);
assert_eq!(hand_type("AAJJJ"), HandType::FiveOfAKind);
assert_eq!(hand_type("T55J5"), HandType::FourOfAKind);
assert_eq!(hand_type("KTJJT"), HandType::FourOfAKind);
assert_eq!(hand_type("QQQJA"), HandType::FourOfAKind);
assert_eq!(hand_type("2J432"), HandType::ThreeOfAKind);
assert_eq!(hand_type("A23J4"), HandType::OnePair);
assert_eq!(hand_type("23456"), HandType::HighCard);
fn name() {
unimplemented!();
}
}