contests/projecteuler/084/src/main.rs

use rand::prelude::*;

#[derive(Debug, Clone, Copy)]
enum CommunityChest {
    ToGo,
    ToJail,
    Empty,
}
struct CommunityChestDeck {
    deck: Vec<CommunityChest>,
    current_index: usize,
}

impl CommunityChestDeck {
    fn next(&mut self) -> CommunityChest {
        self.current_index = (self.current_index + 1) % self.deck.len();
        self.deck[self.current_index]
    }
}

#[derive(Debug, Clone, Copy)]
enum Chance {
    ToGo,
    ToJail,
    ToC1,
    ToE3,
    ToH2,
    ToR1,
    ToNextRailway,
    ToNextUtility,
    GoBack3,
    Empty,
}
struct ChanceDeck {
    deck: Vec<Chance>,
    current_index: usize,
}

impl ChanceDeck {
    fn next(&mut self) -> Chance {
        self.current_index = (self.current_index + 1) % self.deck.len();
        self.deck[self.current_index]
    }
}

#[derive(Debug, Clone, Copy, PartialEq, Eq)]
enum TileType {
    Go,
    Jail,
    GoToJail,
    C1,
    E3,
    H2,
    R1,
    Railway,
    Utility,
    Empty,
    CommunityChest,
    Chance,
}
use TileType::*;

struct Board {
    board: Vec<TileType>,
    current_index: usize,
}

impl Board {
    fn next(&mut self) -> TileType {
        self.current_index = (self.current_index + 1) % self.board.len();
        self.board[self.current_index]
    }

    fn prev(&mut self) -> TileType {
        self.current_index = ((self.current_index as i32 - 1) % self.board.len() as i32) as usize;
        self.board[self.current_index]
    }
}

struct DoubleDice {
    sides: u32,
    rng: ThreadRng,
}

impl DoubleDice {
    // Need to know each specific throw because we need to keep track of the doubles
    fn throw(&mut self) -> (u32, u32) {
        let dice1 = self.rng.gen_range(1..=self.sides);
        let dice2 = self.rng.gen_range(1..=self.sides);

        (dice1, dice2)
    }
}

enum ThrowResult {
    ToJail,
    Moves(u32),
}

fn handle_dice(dice: &mut DoubleDice, past_throws: &mut [(u32, u32)]) -> ThrowResult {
    let dice_throw = dice.throw();
    if past_throws[0] == past_throws[1] && past_throws[1] == dice_throw {
        past_throws[0] = (0, 0);
        past_throws[1] = (0, 0);
        ThrowResult::ToJail
    } else {
        past_throws[0] = past_throws[1];
        past_throws[1] = dice_throw;
        ThrowResult::Moves(dice_throw.0 + dice_throw.1)
    }
}

fn main() {
    println!("Hello, this is Patrick!");
    let mut rng = thread_rng();

    // First create card decks, board and dice
    let mut community_chest_cards = vec![
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::Empty,
        CommunityChest::ToGo,
        CommunityChest::ToJail,
    ];
    community_chest_cards.shuffle(&mut rng);

    let mut chance_cards = vec![
        Chance::Empty,
        Chance::Empty,
        Chance::Empty,
        Chance::Empty,
        Chance::Empty,
        Chance::Empty,
        Chance::ToGo,
        Chance::ToJail,
        Chance::ToC1,
        Chance::ToE3,
        Chance::ToH2,
        Chance::ToR1,
        Chance::ToNextRailway,
        Chance::ToNextRailway,
        Chance::ToNextUtility,
        Chance::GoBack3,
    ];
    chance_cards.shuffle(&mut rng);

    let board_tiles = vec![
        Go,
        Empty,
        CommunityChest,
        Empty,
        Empty,
        R1,
        Empty,
        Chance,
        Empty,
        Empty,
        Jail,
        C1,
        Utility,
        Empty,
        Empty,
        Railway,
        Empty,
        CommunityChest,
        Empty,
        Empty,
        Empty,
        Empty,
        Chance,
        Empty,
        E3,
        Railway,
        Empty,
        Empty,
        Utility,
        Empty,
        GoToJail,
        Empty,
        Empty,
        CommunityChest,
        Empty,
        Railway,
        Chance,
        Empty,
        Empty,
        H2,
    ];

    let mut cc_deck = CommunityChestDeck {
        deck: community_chest_cards,
        current_index: 0,
    };
    let mut chance_deck = ChanceDeck {
        deck: chance_cards,
        current_index: 0,
    };
    let mut board = Board {
        board: board_tiles,
        current_index: 0,
    };

    let mut dice = DoubleDice { sides: 4, rng };
    let mut square_popularity = vec![0; board.board.len()];
    let mut dice_throws = [(0, 0), (0, 0)];

    for _ in 0..2000000 {
        match handle_dice(&mut dice, &mut dice_throws) {
            ThrowResult::ToJail => {
                board.current_index = 10;
            }
            ThrowResult::Moves(n) => {
                let mut next_tile = Empty;
                for _ in 0..n {
                    next_tile = board.next();
                }
                match next_tile {
                    GoToJail => {
                        board.current_index = 10;
                    }
                    CommunityChest => {
                        let card_drawn = cc_deck.next();
                        match card_drawn {
                            CommunityChest::ToGo => {
                                board.current_index = 0;
                            }
                            CommunityChest::ToJail => {
                                board.current_index = 10;
                            }
                            _ => {}
                        }
                    }
                    Chance => {
                        let card_drawn = chance_deck.next();
                        match card_drawn {
                            Chance::ToJail => {
                                board.current_index = 10;
                            }
                            Chance::ToGo => {
                                board.current_index = 0;
                            }
                            Chance::Empty => {}
                            Chance::GoBack3 => {
                                for _ in 0..3 {
                                    _ = board.prev()
                                }
                            }
                            Chance::ToC1 => while board.next() != TileType::C1 {},
                            Chance::ToE3 => while board.next() != TileType::E3 {},
                            Chance::ToH2 => while board.next() != TileType::H2 {},
                            Chance::ToNextUtility => while board.next() != TileType::Utility {},
                            Chance::ToR1 => while board.next() != TileType::R1 {},
                            Chance::ToNextRailway => {
                                let mut next_tile = board.next();
                                while next_tile != TileType::R1 && next_tile != TileType::Railway {
                                    next_tile = board.next();
                                }
                            }
                        }
                    }
                    _ => {}
                }
            }
        }

        square_popularity[board.current_index] += 1;
    }
    let mut squares_sorted: Vec<(usize, u32)> = square_popularity.into_iter().enumerate().collect();
    squares_sorted.sort_by(|(_, a), (_, b)| a.cmp(b));

    println!("Square popularity: {:?}", squares_sorted);
}