6) When adding or deleting records, first load data from the file and store it in the linked list. After batch operation, data will be written from the linked list to the file.

(7) When viewing data, first load the data from the file, store it with the data, and sort it, and use secondary search to speed up the search process, allowing users to view the data many times at a time.

Step 3: Skills

(1) Book information can be structured.