c++沉思录第十章的例子

调试了好久，出现了好大问题。关于虚函数和纯虚函数的知识需要我们好好注意。

#ifndef NEWPICTURE_H
#define NEWPICTURE_H
#include<iostream>
using namespace std;
class P_Node
{
	friend class Picture;
protected:
	P_Node();
	virtual ~P_Node(){};
	virtual int width()const=0;
	virtual int height()const=0;
	virtual void display(ostream &, int, int)const=0;
	int max(int x, int y)const { return x > y ? x : y; }
	void pad(ostream & os, int x, int y)const ;
private:
	int use;
};
class Picture
{
	friend class String_Pic;
	friend class Frame_Pic;
	friend class Hcat_Pic;
	friend class Vcat_Pic;
public:
	Picture();
	Picture(const char * const *, int);
	Picture(const Picture &);
	~Picture();
	Picture & operator =(const Picture &);
	P_Node * p;
	Picture(P_Node * m);
	int height()const;
	int width()const;
	void display(ostream &, int, int)const;
	friend ostream & operator <<(ostream & os, const Picture & p);
	friend Picture frame(const Picture & p);
	friend Picture operator & (const Picture & p, const Picture & q);
	friend Picture operator | (const Picture & p, const Picture & q);
};
class String_Pic :public P_Node
{
	friend class Picture;
	String_Pic(const char* const * arr, int n);
	~String_Pic();
	char** data;
	int size;
	int height()const;
	int width()const;
	void display(ostream &, int, int)const;
};

class Frame_Pic :public P_Node
{
	friend Picture frame(const Picture &);

	int height()const;
	int width()const;
	void display(ostream &, int, int)const;
	Frame_Pic(const Picture &);
	Picture p;
};

class Vcat_Pic :public P_Node
{
	friend Picture operator &
	(const Picture & n, const Picture & m);
	Vcat_Pic(const Picture & n, const Picture & m);
	int height()const;
	int width()const;
	void display(ostream &, int, int)const;
	Picture top, bottom;
};

class Hcat_Pic :public P_Node
{
	friend Picture operator |
	(const Picture & n, const Picture & m);
	Hcat_Pic(const Picture & n, const Picture & m);
	int height()const;
	int width()const;
	void display(ostream &, int, int)const;
	Picture left,right;
};

Picture::Picture(const Picture & m) :p(m.p)
{
	m.p->use++;
}
Picture::Picture(P_Node * m) : p(m){}
Picture::~Picture()
{
	if (--p->use == 0)
		delete p;
}
Picture& Picture::operator=(const Picture & q)
{
	q.p->use++;
	if (--p->use == 0)
		delete p;
	p = q.p;
	return *this;
}
int Picture::height()const{ return p->height(); }
int Picture::width()const { return p->width(); }
void Picture::display(ostream & os, int n, int m)const
{
	p->display(os, n, m);
}
Picture::Picture(const char* const * arr, int n) :p(new String_Pic(arr, n)){}
P_Node::P_Node() :use(1){}

String_Pic::String_Pic(const char * const * arr, int n)
: data(new char*[n]), size(n)
{
	for (int i = 0; i < n; ++i)
	{
		data[i] = new char[strlen(arr[i]) + 1];
		strcpy_s(data[i],strlen(arr[i])+1,arr[i]);
	}
}
String_Pic::~String_Pic()
{
	for (int i = 0; i < size; ++i)
			delete[]data[i];
		delete[]data;

}
int String_Pic::height()const{ return size; }
int String_Pic::width()const
{
	int n = 0;
	for (int i = 0; i < size; ++i)
		n = max(n, strlen(data[i]));
	return n;
}

void String_Pic::display(ostream & os, int row, int width)const
{
	int start = 0;
	if (row >= 0 && row < height())
	{
		os << data[row];
		start = strlen(data[row]);
	}
	pad(os, start, width);
}
int Frame_Pic::height()const{ return p.height() + 2; }
int Frame_Pic::width()const{ return p.width() + 2; }
void Frame_Pic::display(ostream& os, int row, int wd)const
{
	if (row < 0 || row >= height())
	{
		pad(os, 0, wd);
	}
	else
	{
		if ( 0 == row  || row == height() - 1)
		{
			os << "+";
			int i = p.width();
			while (--i >= 0)os << "-";
			os << "+";
		}
		else
		{
			os << "|";
			p.display(os, row - 1, p.width());
			os << "|";
		}
		pad(os, width(), wd);
	}
}
Frame_Pic::Frame_Pic(const Picture & m) :p(m){}
Picture frame(const Picture & m)
{
	return new Frame_Pic(m);
}
Vcat_Pic::Vcat_Pic(const Picture & t, const Picture & b) : top(t), bottom(b){}
Hcat_Pic::Hcat_Pic(const Picture & l, const Picture & r) : left(l),right(r){}
Picture operator &(const Picture & n, const Picture & m)
{
	return new Vcat_Pic(n, m);
}
Picture operator |(const Picture & n, const Picture & m)
{
	return new Hcat_Pic(n, m);
}
int Vcat_Pic::height()const{ return top.height() + bottom.height(); }
int Vcat_Pic::width()const{ return max(top.width(), bottom.width()); }
int Hcat_Pic::height()const{ return max(left.height(), right.height()); }
int Hcat_Pic::width()const{ return left.width()+ right.width(); }
void Vcat_Pic::display(ostream& os, int row, int wd)const
{
	if (row >= 0 && row < top.height())
		top.display(os, row, wd);
	else
	{
		if (row < top.height() + bottom.height())
			bottom.display(os, row - top.height(), wd);
		else
			pad(os, 0, wd);
	}
}
void Hcat_Pic::display(ostream & os, int row, int wd)const
{
	left.display(os, row, left.width());
	right.display(os, row, right.width());
	pad(os, width(), wd);
}
void P_Node::pad(ostream & os, int x, int y)const
{
	for (int i = x; i < y; ++i)
		os << " ";
}

ostream & operator <<(ostream & os, const Picture & p)
{
	int ht = p.height();
	for (int i = 0; i < ht; ++i)
	{	p.display(os, i, 0); os << endl;}
	return os;
}
#endif

#include"NewPicture.h"
#include<iostream>
using namespace std;
int main()
{
	char * init[] = { "Summer", "love", "Xieweizhong" };
	Picture p(init, 3);
	cout << p << endl;
	cout << frame((p | frame(p)) | (p | frame(p))) << endl;
	cout << frame((p & frame(p)) | (p | frame(p))) << endl;
	cout << frame((p | frame(p)) | (p & frame(p))) << endl;
	cout << frame((p & frame(p)) | (p & frame(p))) << endl;
	cout << frame((p | frame(p)) & (p | frame(p))) << endl;
	cout << frame((p & frame(p)) & (p | frame(p))) << endl;
	cout << frame((p | frame(p)) & (p & frame(p))) << endl;
	cout << frame((p & frame(p)) & (p & frame(p))) << endl;
	return 0;
}