def as_path_change(paths):
    """ mark the idx at which AS path changes

    Args:
        paths (list of list of ASN): [[ASN,...],...]

    Returns:
        list of int, index of change is set to 1, otherwise 0
    """
    change = [0] * len(paths)
    for idx, path in enumerate(paths):
        if idx > 0:
            if path != paths[idx-1]:
                change[idx] = 1
    return change