def get_top_k_matrix(A: np.ndarray, k: int=128) -> np.ndarray:
    num_nodes = A.shape[0]
    row_idx = np.arange(num_nodes)
    A[(A.argsort(axis=0)[:(num_nodes - k)], row_idx)] = 0.0
    norm = A.sum(axis=0)
    norm[(norm <= 0)] = 1
    return (A / norm)
def get_top_k_matrix(A: np.ndarray, k: int=128) -> np.ndarray:
    num_nodes = A.shape[0]
    row_idx = np.arange(num_nodes)
    A[(A.argsort(axis=0)[:(num_nodes - k)], row_idx)] = 0.0
    norm = A.sum(axis=0)
    norm[(norm <= 0)] = 1
    return (A / norm)