$$Problem$$

Design and implement a system that can manage the information of students.Student information includes: student number, name, age and gender; Course grade information includes: course number, course name, grade and teacher. It can insert, delete, update, query, sort and count data according to student information and score information.

$(1)$ The sorting operation in the system needs at least two sorting methods of quick sort, heap sort and merge sort;

$(2)$ At least two search methods are used in the search process in the system$$

$$Data structures$$

$(1)$ Linked list;

$(2)$ sorting algorithm.

$2$ Huffman coding and decoding $(********)$