#include<iostream>
using namespace std;
#define PI 3.14
class Circle
{
	//訪(fǎng)問(wèn)權(quán)限
	//公共權(quán)限
public:
	//屬性
	int r;
	//行為
	double calculate()
	{
		return 2 * PI * r;
	}
};
int main()
{
	Circle a;
	a.r = 2;
	cout << a.calculate() << endl;
	system("pause");
	return 0;
}

#include<iostream>
#include<string>
using namespace std;
class student
{
public:
	string name;
	int Id;
	void CinSudent()
	{
		cin >> name;
		cin >> Id;
	}
	void ShowStudent()
	{
		cout << name << endl;
		cout << Id << endl;
	}
};
int main()
{
	student a;
	a.CinSudent();
	a.ShowStudent();
	system("pause");
	return  0;
}

訪(fǎng)問(wèn)權(quán)限有三種：
1.public  公共權(quán)限
2.protected  保護(hù)權(quán)限
3.private   私有權(quán)限

class Box
{
   public:
      double length;
      void setWidth( double wid );
      double getWidth( void );
};

class Box
{
   protected:
      double length;
      void setWidth( double wid );
      double getWidth( void );
};

class Box
{
   private:
      double length;
      void setWidth( double wid );
      double getWidth( void );
};

#include<iostream>
using namespace std;
struct C1
{
	int m_A;//默認(rèn)權(quán)限為公有
};
class C2
{
	int m_A;//默認(rèn)權(quán)限為私有
};
int main()
{
	C1 c1;
	C2 c2;
	c1.m_A = 100;
	//c2.m_A = 100; 此處無(wú)法訪(fǎng)問(wèn)
	return 0;
}

#include<iostream>
#include<string>
using namespace std;
class Person
{
public:
	void Setname(string name1)
	{
		name = name1;
	}
	string Showname()
	{
		return name;
	}
	int Showage()
	{
		return age;
	}
private:   //私有權(quán)限
	string name;
	int age=18;
};
int main()
{
	Person a;
	a.Setname("張三");
	cout << "姓名為： " << a.Showname() << endl;
	cout << "年齡為： " << a.Showage() << endl;
	system("pause");
	return 0;
}

#include<iostream>
#include<string>
using namespace std;
class Cube
{
public:
	//設(shè)置長(zhǎng)
	void setL(int l)
	{
		m_L = l;
	}
	//設(shè)置寬
	void setW(int w)
	{
		m_W = w;
	}
	//設(shè)置高
	void setH(int h)
	{
		m_H = h;
	}
	//獲取長(zhǎng)
	int getL()
	{
		return m_L;
	}
	//獲取寬
	int getW()
	{
		return m_W;
	}
	//獲取高
	int getH()
	{
		return m_H;
	}
	//獲取面積
	int calculateS()
	{
		return 2 * (m_L * m_W + m_L * m_H + m_W * m_H);
	}
	//獲取體積
	int calculateV()
	{
		return m_L * m_H * m_W;
	}
	//利用成員函數(shù)判斷兩個(gè)立方體是否相等
	bool isSameByClass(Cube& c)
	{
		if (m_H == c.getH() && m_L == c.getL() && m_W == c.getW())
			return true;
		else
			return false;
	}
private:
	int m_L;//長(zhǎng)
	int m_W;//寬
	int m_H;//高
};
//利用全局函數(shù)判斷兩個(gè)立方體是否相等
bool isSame(Cube &c1,Cube &c2)
{
	if (c1.getH() == c2.getH() && c1.getL() == c2.getL() && c1.getW() == c2.getW())
		return true;
	else
		return false;
}
int main()
{
	Cube c1;
	c1.setH(10);
	c1.setL(13);
	c1.setW(45);
	cout << "c1面積是：" << c1.calculateS() << endl;
	cout << "c2體積是：" << c1.calculateV() << endl;
	Cube c2;
	c2.setH(10);
	c2.setL(13);
	c2.setW(45);
//利用全局函數(shù)判斷
	if (isSame(c1, c2))
		cout << "c1和c2相等" << endl;
	else
		cout << "c1和c2不相等" << endl;
//利用成員函數(shù)判斷
	if (c1.isSameByClass(c2))
		cout << "c1和c2相等" << endl;
	else
		cout << "c1和c2不相等" << endl;
	system("pause");
	return 0;
}

#include<iostream>
using namespace std;
class Point
{
public:
	//設(shè)置x
	void setX(int x)
	{
		m_X = x;
	}
	//設(shè)置y
	void setY(int y)
	{
		m_Y = y;
	}
	//獲取x
	int  getX()
	{
		return m_X;
	}
	int getY()
	{
		return m_Y;
	}
private:
	int m_X;
	int m_Y;

};
class Circle
{
public:
	//設(shè)置半徑
	void setR(int r)
	{
		m_R = r;
	}
	//獲取半徑
	int getR()
	{
		return m_R;
	}
	//設(shè)置圓心
	void setCenter(int x, int y)
	{
		m_Center.setX(x);
		m_Center.setY(y);
	}
	//獲取圓心
	Point getCenter()
	{
		return m_Center;
	}
private:
	int m_R; //半徑
	Point m_Center;//圓心
};
//判斷點(diǎn)和圓的關(guān)系
void isInCircle(Circle& c, Point& p)
{
	//計(jì)算距離的平方
	int distance = (c.getCenter().getX() - p.getX()) * (c.getCenter().getX() - p.getX()) +
		           (c.getCenter().getY() - p.getY()) * (c.getCenter().getY() - p.getY());
	//計(jì)算半徑的平方
	int RDistance = c.getR() * c.getR();
	//判斷關(guān)系
	if (distance == RDistance)
		cout << "點(diǎn)在圓上" << endl;
	else if (distance > RDistance)
		cout << "點(diǎn)在圓外" << endl;
	else
		cout << "點(diǎn)在圓內(nèi)" << endl;
}
int main()
{
	//創(chuàng)建一個(gè)圓
	Circle c;
	c.setR(10);
	c.setCenter(10, 0);
	Point p;
	p.setX(10);
	p.setY(10);
	//判斷關(guān)系
	isInCircle(c,p);
	system("pause");
	return 0;
}