def determine_lengths(dtrajs):
    r"""
    Determines the lengths of all trajectories

    Parameters
    ----------
    dtrajs : list of int-arrays
        discrete trajectories
    """
    if (isinstance(dtrajs[0], (int))):
        return len(dtrajs) * np.ones((1))
    lengths = np.zeros((len(dtrajs)))
    for i in range(len(dtrajs)):
        lengths[i] = len(dtrajs[i])
    return lengths
r"""
    Determines the lengths of all trajectories

    Parameters
    ----------
    dtrajs : list of int-arrays
        discrete trajectories