c++抽象类继承

#include<iostream>
#include<string>
#include<sstream>
using namespace std;
class UniversityObject
{
  public:
  virtual char* getSummary();
};
class Student:public UniversityObject
{
  private:
          string name,register_str;
  public:
          Student(string,string);//构造函数声明
          char* getSummary();//输出函数
};
class Lecture:public UniversityObject
{
  private:
          float room_num;
          int seat_num;
  public:
          Lecture(float,int);//构造函数声明
          char* getSummary();//输出函数
};
class Module:public UniversityObject
{
  private:
          string cno,sno;