diff --git a/day22/Cargo.toml b/day22/Cargo.toml new file mode 100644 index 0000000..3180d24 --- /dev/null +++ b/day22/Cargo.toml @@ -0,0 +1,9 @@ +[package] +name = "day22" +version = "0.1.0" +authors = ["inga-lovinde <52715130+inga-lovinde@users.noreply.github.com>"] +edition = "2018" + +# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html + +[dependencies] diff --git a/day22/src/main.rs b/day22/src/main.rs new file mode 100644 index 0000000..567d97c --- /dev/null +++ b/day22/src/main.rs @@ -0,0 +1,128 @@ +use std::collections::{HashSet, HashMap, VecDeque}; +use std::error::Error; +use std::io::{self, BufRead}; + +#[derive(Debug)] +struct GameResult { + winner: usize, + cards: [VecDeque; 2], +} + +fn game_easy(mut cards: [VecDeque; 2]) -> GameResult { + loop { + let card0 = cards[0].pop_front().unwrap(); + let card1 = cards[1].pop_front().unwrap(); + + if card0 < card1 { + cards[1].push_back(card1); + cards[1].push_back(card0); + } else if card0 > card1 { + cards[0].push_back(card0); + cards[0].push_back(card1); + } else { + panic!("cards are equal"); + } + + if cards[0].len() == 0 { + return GameResult { + winner: 1, + cards, + } + } + + if cards[1].len() == 0 { + return GameResult { + winner: 0, + cards, + } + } + } +} + +fn game_hard(original_cards: &[VecDeque; 2]) -> GameResult { + let mut cards = original_cards.clone(); + let mut states = HashSet::new(); + + loop { + if states.contains(&cards[0]) { + //println!("loop return from game {}", current_game_count); + //result_cache.insert(original_cards.clone(), 0); + return GameResult { + winner: 0, + cards, + }; + } + + states.insert(cards[0].clone()); + + let card0 = cards[0].pop_front().unwrap(); + let card1 = cards[1].pop_front().unwrap(); + + let round_winner = if cards[0].len() >= card0 && cards[1].len() >= card1 { + game_hard(&[cards[0].iter().cloned().take(card0).collect(), cards[1].iter().cloned().take(card1).collect()]).winner + } else if card0 < card1 { + 1 + } else if card0 > card1 { + 0 + } else { + panic!("cards are equal"); + }; + + match round_winner { + 0 => { + cards[0].push_back(card0); + cards[0].push_back(card1); + }, + 1 => { + cards[1].push_back(card1); + cards[1].push_back(card0); + }, + _ => panic!("wrong winner value"), + } + + if cards[0].len() == 0 { + //println!("winner 1 return from game {}", current_game_count); + return GameResult { + winner: 1, + cards, + }; + } + + if cards[1].len() == 0 { + //println!("winner 0 return from game {}", current_game_count); + return GameResult { + winner: 0, + cards, + }; + } + } +} + +fn handle_result(game_result: GameResult) { + let mut sum = 0; + let len = game_result.cards[game_result.winner].len(); + for i in 0..len { + sum += (len-i) * game_result.cards[game_result.winner][i]; + } + println!("{:?}", game_result); + println!("{}", sum); +} + +fn main() -> Result<(), Box> { + let stdin = io::stdin(); + let mut cards: [VecDeque; 2] = Default::default(); + let mut current_player = usize::MAX; + for line_result in stdin.lock().lines() { + let line = line_result?; + if line.starts_with("Player") { + current_player = line.strip_prefix("Player ").unwrap().strip_suffix(":").unwrap().parse::()? - 1; + } else if line != "" { + cards[current_player].push_back(line.parse()?); + } + } + + handle_result(game_easy(cards.clone())); + handle_result(game_hard(&cards)); + + Ok(()) +}