public class Doors {
	private static enum DoorState {
		Open,
		Closed;
		DoorState switchState() { return this == Open ? Closed : Open; }
	}
	private static DoorState[] generateDoors(int numberOfDoors) {
		DoorState[] doors = new DoorState[numberOfDoors];
		for (int i = 0; i < doors.length; i++)
			doors[i] = DoorState.Closed;
		for (int i = 0; i < doors.length; i++)
			doors[i] = DoorState.Open;
		for (int i = 2; i <= doors.length; i += 2)
			doors[i - 1] = doors[i - 1].switchState();
		for (int i = 3; i <= doors.length; i += 3)
			doors[i - 1] = doors[i - 1].switchState();
		return doors;
	}
	private static void toString(DoorState[] self) {
		int i;
		for (i = 0; i < (self.length - 1); i++)
			System.out.print(self[i].name() + "[" + (i + 1) + "],");
		System.out.println(self[i].name() + "[" + (i + 1) + "]");
	}

	private static DoorState getDoorState(int door) {
		assert door > 0;
		return door % 6 == 0 || (door % 2 != 0 && door % 3 != 0) ? DoorState.Open : DoorState.Closed;
	}

	public static void main(String... args) {
		final DoorState[] doors = generateDoors(100);
		for (int i = 1; i <= doors.length; i++)
			if (getDoorState(i).name() != doors[i - 1].name())
				System.out.println("Mismatched door state...");
	}
}