algo4: unionfind: Successor query supporting deletion
    -- new division
algo4: array: matrix: set_matrix_zeros: Revisited
algo4: array: matrix: rotate_image: Revisited
algo4: array: matrix: maximum_sub_matrix_sum: Revisited
algo4: array: matrix: print_matrix_upper_right_to_bottom_left: Revisited
algo4: array: matrix: spiral_matrix: Revisited