def cb_valid_actions(state):
    """
    Helper function to return valid actions at conditional bandit states. Used for plotting maze.
    :param state: state tuple
    :return: list of valid actions
    """

    if state == [3, 6]:
        return [2, 3]
    elif state == [9, 6]:
        return [2, 3]
    elif state == [6, 3]:
        return [0, 1]
    elif state == [6, 9]:
        return [0, 1]
    else:
        return []