What's Changed
* [Comprehensive upgrade of overall structure](https://github.com/Thinklab-SJTU/ML4CO-Kit/commit/f63082744825d878c024a64f40214d74f5a9e167) heatingma
* After adjustment, the IO adjustment method for each solver is as follows, ``*``Representing a new read-write function.
| Solver | The original read-write function | After Adjusted | Equivalent method |
|:--------------:|:----------------------------------- |:------------------------------- | ------------------------------------ |
| ``TSPSolver`` | ``from_tsp`` | ``from_tsplib`` | ``tsp_file_path`` |
| | ``from_txt`` | ``from_txt`` | ``ref=True`` |
| | ``from_data`` | ``from_data`` | ``points`` |
| | ``read_tours`` | ``from_data`` | ``tours``, ``ref=False`` |
| | ``read_ref_tours`` | ``from_data`` | ``tours``, ``ref=True`` |
| | ``read_ref_tours_from_opt_tour`` | ``from_tsplib`` | ``tour_file_path``, ``ref=True`` |
| | ``to_tsp`` | ``to_tsplib_folder`` | ``tsp_save_dir``, ``tsp_filename`` |
| | ``to_opt_tour`` | ``to_tsplib_folder`` | ``tour_save_dir``, ``tour_filename`` |
| | ``*`` | ``from_tsplib_folder`` | ``--`` |
| ``MISSolver`` | ``from_gpickle_folder`` | ``from_gpickle_result_folder`` | ``--`` |
| | ``read_ref_sel_nodes_num_from_txt`` | ``from_txt_only_sel_nodes_num`` | ``ref=True`` |
| | ``*`` | ``from_gpickle_result`` | ``--`` |
| | ``*`` | ``from_txt`` | ``--`` |
| | ``*`` | ``from_graph_data`` | ``--`` |
| | ``*`` | ``from_adj_matrix`` | ``--`` |
| | ``*`` | ``to_gpickle_result_folder`` | ``--`` |
| | ``*`` | ``to_txt`` | ``--`` |
| ``CVRPSolver`` | ``from_data`` | ``from_data`` | ``depots ... capacities`` |
| | ``from_txt`` | ``from_txt`` | ``ref=True`` |
| | ``from_vrp`` | ``from_vrplib`` | ``vrp_file_path`` |
| | ``read_tours`` | ``from_data`` | ``tours``, ``ref=False`` |
| | ``read_ref_tours`` | ``from_data`` | ``tours``, ``ref=True`` |
| | ``read_ref_tours_from_sol`` | ``from_vrplib`` | ``sol_file_path`` |
| | ``to_vrp`` | ``to_vrplib_folder`` | ``vrp_save_dir``, ``vrp_filename`` |
| | ``to_sol`` | ``to_vrplib_folder`` | ``sol_save_dir``, ``sol_filename`` |
| | ``*`` | ``from_vrplib_folder`` | ``--`` |
| ``TSPSolver`` | ``from_atsp`` | ``from_tsplib`` | ``atsp_file_path`` |
| | ``from_atsp_folder`` | ``from_tsplib_folder`` | ``atsp_folder_path`` |
| | ``from_txt`` | ``from_txt`` | ``ref=True`` |
| | ``from_data`` | ``from_data`` | ``dists`` |
| | ``read_tours`` | ``from_data`` | ``tours``, ``ref=False`` |
| | ``read_ref_tours`` | ``from_data`` | ``tours``, ``ref=True`` |
| | ``read_ref_tours_from_opt_tour`` | ``from_tsplib`` | ``tour_file_path``, ``ref=True`` |
| | ``read_ref_tours_from_folder`` | ``from_tsplib_folder`` | ``tour_folder_path``, ``ref=True`` |
| | ``to_atsp_folder`` | ``to_tsplib_folder`` | ``atsp_save_dir``, ``atsp_filename`` |
| | ``to_opt_tour_folder`` | ``to_tsplib_folder`` | ``tour_save_dir``, ``tour_filename`` |