/*使用结构体数组，将学生的数据按成绩从高到低排序显示到屏幕上， 将学生中不及格学生的姓名显示出来 写一个函数，获取成绩低于平均分的学生记录并返回低于平均分的学生人数*/(using an array of structures, the student's data is displayed on the screen from high to low, and the student's name is displayed to write a function, to get a student record below the average score and to return the number of students below the average.)