1.定义学生类，包括学号、姓名、性别、多门课程的成绩，学生分为两类，课程门数不同，并将课程成绩全部初始化为0；假设有n个学生，由键盘输入学生信息；
2.定义类成员函数，完成修改每个学生的信息，计算每个学生的平均成绩，按课程统计每门课程的平均成绩、最高分和最低分；
3.同时输出所有学生信息；
4.通过输入学生学号或姓名查询某学生的信息。(1. Define student category, including student number, name, gender, and scores of multiple courses. Students are divided into two categories, with different number of courses, and all course scores are initialized to 0. Suppose there are n students, input student information by keyboard;
2. Define the class member function, modify the information of each student, calculate the average score of each student, and count the average score, the highest score and the lowest score of each course according to the course;
3. Output all student information at the same time;
4. Query the information of a student by inputting the student number or name.)