tdd

bowling_game.rs

//볼링 한 game은 10번 frame으로 구성
//1 frame 당 2번 공 던지기 가능
//2번 공 번져서 모두 쓰러뜨림 -> spare -> 다음 라운드의 점수를 2배로
//1번에 -> strike -> 다음 + 다다음 라운드의 점수를 2배
//마지막 frame -> 3번 던질 수 있음 단, 2번을 최소 스페어해야됨
pub struct Game {
    score: u32,
    rolls: Vec<u32>,
}

impl Game {
    pub fn new() -> Game {
        Game {
            score: 0,
            rolls: vec![],
        }
    }
    pub fn roll(&mut self, pin: u32) {
        self.rolls.push(pin);
    }

    pub fn score(&mut self) -> u32 {
        let mut round = 0;
        (0..10).for_each(|_| {
            if self.rolls[round] == 10 {
                //strike
                self.score += 10 + self.rolls[round + 1] + self.rolls[round + 2];
                round += 1;
            } else if self.rolls[round] + self.rolls[round + 1] == 10 {
                //spare
                self.score += 10 + self.rolls[round + 2];
                round += 2;
            } else {
                self.score += self.rolls[round] + self.rolls[round + 1];
                round += 2;
            }
        });

        self.score
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn game_starts() {
        //set up 혹은 step up test -> 기본 골조 test임
        let _ = Game::new();
    }

    #[test]
    fn gutter_game() {
        let mut game = Game::new();
        (0..20).for_each(|_| game.roll(0));
        assert_eq!(game.score(), 0);
    }

    #[test]
    fn all_ones() {
        let mut game = Game::new();
        (0..20).for_each(|_| game.roll(1));
        assert_eq!(game.score(), 20);
    }

    #[test]
    fn one_spare() {
        let mut game = Game::new();
        game.roll(5);
        game.roll(5); //spare 발생
        game.roll(4); //점수 2배이므로 4*2 = 8로 계산됨
        (0..17).for_each(|_| game.roll(0));
        assert_eq!(game.score(), 18);
    }

    #[test]
    fn one_strike() {
        let mut game = Game::new();
        game.roll(10);
        game.roll(5); //5 * 2 = 10
        game.roll(5); //5 * 2 = 10
        (0..16).for_each(|_| game.roll(0));
        assert_eq!(game.score(), 30);
    }

    #[test]
    fn two_strike() {
        let mut game = Game::new();
        game.roll(10);
        game.roll(5); //5 * 2 = 10
        game.roll(5); //5 * 2 = 10
        game.roll(10); //5 * 2 = 10
        game.roll(2); //5 * 2 = 10
        game.roll(3); //5 * 2 = 10
        (0..14).for_each(|_| game.roll(0));
        assert_eq!(game.score(), 60);
    }

    #[test]
    fn perfect_game() {
        let mut game = Game::new();
        (0..12).for_each(|_| game.roll(10));
        assert_eq!(game.score(), 300);
    }
}