diff options
| -rw-r--r-- | src/day4.rs | 36 |
1 files changed, 34 insertions, 2 deletions
diff --git a/src/day4.rs b/src/day4.rs index 9f4f82e..945f9a5 100644 --- a/src/day4.rs +++ b/src/day4.rs @@ -25,7 +25,7 @@ mod bingo_internals { } #[derive(Debug,Clone,Copy)] - struct WonBingoCard{ + pub struct WonBingoCard{ score : usize, round : usize, } @@ -34,6 +34,9 @@ mod bingo_internals { pub fn get_score(&self) -> usize { self.score } + pub fn get_winning_round(&self) -> usize { + self.round + } } impl UnfinishedBingoCard { @@ -255,6 +258,13 @@ mod bingo_internals { self.round } + pub fn get_winner_cards_ascending(&self) -> impl Iterator<Item=(usize, & WonBingoCard)>+Clone { + self.cards.iter().enumerate().filter_map(|(winner_number, card)| match card { + BingoCard::Unfinished(_) => { None } + BingoCard::Won(card) => { Some((winner_number, card)) } + }) + } + pub fn get_winner_cards_scores_ascending(&self) -> impl Iterator<Item=WinnerNumberAndScore>+Clone+'_ { self.cards.iter().enumerate().filter_map(|(winner_number, card)| card.get_score().map(|score| WinnerNumberAndScore { winner_number, score})) } @@ -489,7 +499,7 @@ fn find_first_player_that_hasnt_won(game : &BingoGame) -> Option<usize> { }) } -#[aoc(day4, part2)] +#[aoc(day4, part2, StopBeforeLastPlayerFinishes)] pub fn solve_part2(input : &GameAndInput) -> Result<usize, BingoGameSolutionError> { use std::ops::ControlFlow as Cf; let (game_before_last_card_finishes, mut input_iterator) = run_game_until_only_one_player_left(input.game.clone(), input.input.iter())?; @@ -517,6 +527,28 @@ pub fn solve_part2(input : &GameAndInput) -> Result<usize, BingoGameSolutionErro } } +#[aoc(day4, part2, JustContinueAndFindOutAfter)] +pub fn solve_part2_just_finish_and_find_out_after(input : &GameAndInput) -> Result<usize, BingoGameSolutionError> { + use std::cmp::max; + let end_state = input.input.iter().fold(input.game.clone(), |game, value| game.cross_number(*value)); + let (winner_count, last_round_someone_won) = end_state.get_winner_cards_ascending() + .fold((0,0), | (winner_count, last_round_someone_won), (_, winner) | (winner_count + 1, max(last_round_someone_won, winner.get_winning_round()))); + if winner_count != end_state.get_number_of_cards_in_game() { + Err(BingoGameSolutionError::InsufficientInput { current_game_state : end_state}) + } + else { + let mut last_winners = end_state.get_winner_cards_ascending() + .filter(|(_, winner)| winner.get_winning_round() == last_round_someone_won); + let last_winners_count = last_winners.clone().count(); + if last_winners_count == 1 { + Ok(last_winners.next().unwrap().1.get_score()) + } + else { + Err(BingoGameSolutionError::Tie{ winners : last_winners.map(|(winner_number, card)| WinnerNumberAndScore{ winner_number, score : card.get_score()}).collect() }) + } + } +} + #[cfg(test)] pub mod tests{ |