定义毕业生类，继承了大学生类和研究生类的成员，另外新增毕业学校、毕业时间、就业单位属性；学生类中增加一属性：学生获奖情况（提示：获奖情况可能有多个，最好使用聚合类）

基本要求：定义毕业生类的构造函数和析构函数，通过构造函数初始化各基类和聚合类成员；

高级要求：定义重载构造函数，能通过键盘输入数据，调用不同的构造函数进行-Graduates of the definition of class, inherited type of university students and post-graduate class members, another new graduate school, graduation time, employment units attribute　students to add one attribute category: Student Awards (hint: the situation may have a number of award-winning, the best use of polymer-type) basic requirements: the definition of the graduates of Class constructor and destructor, through the constructor initializes the base class and class member polymerization　Senior requirements: the definition of overloaded constructor, through the keyboard input data, call a different constructor for