Method add_car

1603-design-parking-system.rs:14–22

(&mut self, car_type: i32)

    }

    fn add_car(&mut self, car_type: i32) -> bool {
        let car_type = car_type as usize - 1;
        if self.current.get(car_type).unwrap() + 1 > *self.max.get(car_type).unwrap() {
            false
        } else {
            *self.current.get_mut(car_type).unwrap() += 1;
            true
        }
    }
}

fn main() {