一道C++编程题？

你这个目录有点多，我没有写全，所以运行结果如下图，你可以自己在代码里补全。

#include

#include

#include

using namespace std;

class Title{//标题的基类

protected:

    string no;//序号

    string name;//名称

public:

    Title(string no1,string name1){

        no=no1;

        name=name1;

    }

    virtual void Print()=0;//打印本级标题 纯虚函数

};

class FirstTitle:public Title{//一级标题

public:

    FirstTitle(string no1,string name1):Title(no1,name1){}

    void Print(){

        cout<

    }

};

class SecondTitle:public Title{//二级标题

public:

    SecondTitle(string no1,string name1):Title(no1,name1){}

    void Print(){

        cout<<"  "<

    }

};

class ThirdTitle:public Title{//三级标题

public:

    ThirdTitle(string no1,string name1):Title(no1,name1){}

    void Print(){

        cout<<"    "<

    }

};

int main(int argc, const char * argv[]) {

    vector titles;

    Title *two=new FirstTitle("2","数据类型及表达式");

    Title *two_one=new SecondTitle("2.1","C++的数据类型"),*two_two=new SecondTitle("2.2","常量"),*two_three=new SecondTitle("2.3","变量"),*two_four=new SecondTitle("2.4","C++的运算符");

    Title *two_two_one=new ThirdTitle("2.2.1","什么是常量"),*two_two_two=new ThirdTitle("2.2.2","数值常量");

    //....

    titles.push_back(two);

    titles.push_back(two_one);

    titles.push_back(two_two);titles.push_back(two_two_one);titles.push_back(two_two_two);

    titles.push_back(two_three);

    titles.push_back(two_four);

    //....

    for(int i=0;i

        titles[i]->Print();

        cout<

    }

    return 0;

}