ex10

  定义一个CStudent类，在该类定义中包括：一个数据成员score（分数）及两个静态数据成员total（总分）和学生人数count：成员函数STC(float s)设置分数，求总分，累计学生人数：静态成员函数Sum返回总分；静态成员函数Average求平均值。在main函数中，输入某班同学的成绩，并调用上述函数求全班学生的总分和平均分。(Define a CStudent class in the class definition, including: a data member score (Score) and two static data members total (total score) and the number of students count: the member function STC (float s) set score, find the total score, the cumulative Number of students: the static member function Sum return score static member function Average average. In the main function, enter the results of a class of students seeking the total score and the average score of students in the class and call the above function.)