#include <iostream>
#include<string>
using namespace std;
class Student//声明基类
{
public://公用部分
  Student(int n, string nam)//基类构造函数
  {
   num=n;
   name=nam;
  }
  void display( )//输出基类数据成员
  {
   cout<<"num:"<<num<<endl;
   cout<<"name:"<<name<<endl;
  }
protected://保护部分
  int num;//基类有两个数据成员
  string name;
};
class Student1: public Student//声明公用派生类Student1
{
public:
  Student1(int n,char nam[10],int a):Student(n,nam)//派生类构造函数
  {age=a;}//在此处只对派生类新增的数据成员初始化
  void show( ) //输出num，name和age
  {
   display( ); //输出num和name
   cout<<"age: "<<age<<endl;
  }
private://派生类的私有数据
  int age; //增加一个数据成员
};
class Student2:public Student1 //声明间接公用派生类Student2
{
public://下面是间接派生类构造函数
  Student2(int n, string nam,int a,int s):Student1(n,nam,a) {score=s;}
  void show_all( ) //输出全部数据成员
  {
   show( ); //输出num和name
   cout<<"score:"<<score<<endl; //输出age
  }
private:
  int score; //增加一个数据成员
};
int main( )
{
  Student2 stud(10010,"Li",17,89);
  stud.show_all( ); //输出学生的全部数据
  return 0;
}

num:10010
name:Li
age:17
score:89

  Student(int n, string nam)

  Student1(int n, string nam],int a):Student(n,nam)

  Student2(int n, string nam,int a,int s):Student1(n,nam,a)

  Student2(int n, string nam,int a,int s):Student1(n,nam),student1(n, nam, a)

class A //基类
{
public:
  int i;
protected:
  void f2( );
  int j;
private:
  int k;
};
class B: public A //public方式
{
public:
  void f3( );
protected:
  void f4( );
private:
  int m;
};
class C: protected B //protected方式
{
public:
  void f5( );
private:
  int n;
};