def get_voxel_index(coord, s):
    """
    Computes voxel index in an s x s x s neighborhood based on the provide coordinates
    Note: returned index may be negative or > (s * s * s) if the provided index coordinate corresponds to a voxel at the
    boundary of the s x s x s block
    :type coord: tuple[int]
    :param coord: tuple containing (x, y, z) coordinates of the voxel
    :type s: int
    :param s: lateral size of the neighborhood
    :return: index of the voxel at the specified coordinate
    """
    x, y, z = coord
    return s * s * z + s * y + x