/*
?*?ex10_3.cpp
?*
?*??3．利用抽象類和虛函數改寫第9?章習題中的Shape?類層次。
?*??再編寫一個totalArea（）函數計算任意兩個形狀的面積之和。
?*
?*/
#include?
#include?
#include?
using?namespace?std;
//-----------------------------------------
class?Shape
{
public:
	virtual?double?area（）const?=?0;
	virtual?double?perimeter（）const?=?0;
	virtual?void?scale（double?factor）?=?0;
};
//-----------------------------------------
class?Triangle?:?public?Shape
{
public:
	Triangle（double?a=1?double?b=1?double?c=1）;
	double?area（）const;
	double?perimeter（）const;
	void?scale（double?factor）;
	double?getA（）{return?a;}
	double?getB（）{return?b;}
	double?getC（）{return?c;}
	//others......
private:
	double?a?b?c;
	static?bool?validate（double?a?double?b?double?c）;
};
Triangle::Triangle（double?x?double?y?double?z）
{
	bool?v?=?validate（xyz）;
	assert（v）;
	a=x;?b=y;?c=z;
}

double?Triangle::area（）const
{
	double?p?=?（a+b+c）/2;
	double?s?=?p*（p-a）*（p-b）*（p-c）;
	return?sqrt（s）;
}
double?Triangle::perimeter（）const
{
	return?a+b+c;
}
//others......
void?Triangle::scale（double?factor）{
	assert（factor>0）;
	a?*=?factor;
	b?*=?factor;
	c?*=?factor;
}

bool?Triangle::validate（double?a?double?b?double?c）
{
	if（（a<=0）?||?（b<=0）?||?（c<=0））
		return?false;
	if（（a+b<=c）?||?（a+c<=b）?||?（b+c<=a））
		return?false;
	return?true;
}
//----------------------------------
class?Rectangle:public?Shape
{
public:
	Rectangle（double?w=1.0double?h=1.0）;
	double?area（）const;
	double?perimeter（）const;
	void?scale（double?f）;
	double?width（）{return?_width;}
	double?height（）{return?_height;}
private:
	double?_height;
	double?_width;
};
Rectangle::Rectangle（double?wdouble?h）
{?assert（w>0）;
assert（h>0）;
_width?=?w;
_height?=?h;
}
double?Rectangle::area（）const
{
	return?_height*_width;
}
double?Rectangle::perimeter（）const
{
	return?2*（_height+_width）;
}
void?Rectangle::scale（double?f）
{
	assert（f?>?0）;
	_height?*=?f;
	_width?*=?f;
}
//------------------------------
class?Circle?:?public?Shape
{
public:
	Circle（double?r?=?1.0）;
	double?area（）const;
	double?perimeter（）const;
	void?scale（double?factor）;
	double?getRadius（）{return?radius;}
private:
	double?radius;
};
const?double?pi=3.1415926;
Circle::Circle（double?r）
{
	assert（r>0）;
	radius?=?r;
}
double?Circle::area（）const
{
	return?pi*radius*radius;
}
double?Circle::perimeter（）const
{
	return?pi*radius*2;
}
void?Circle::scale（double?f）
{
	assert（f>0）;
	radius?*=?f;
}
//------------------------------------
double?totalArea（Shape&?s1?Shape&?s2）
{
	return?s1.area（）+s2.area（）;
}
//-------------------------
int?main（）
{
	Rectangle?r（53）;
	cout<<“Rectangle?r:\t“<<“width:?“<	<<“\theight:“<	cout<<“area=“<	Circle?c（4）;
	cout<<“Circle?c:\t“<<“radius:?“<	cout<<“area=“<	Triangle?t（534）;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2018-07-24?20:35??excercise\
?????文件????????1848??2017-02-06?19:06??excercise\ch11\ex11_6\array.h
?????文件?????????371??2017-02-06?16:16??excercise\ch10\ex10_4\basket.cpp
?????文件?????????287??2017-02-06?16:16??excercise\ch10\ex10_4\basket.h
?????文件?????????604??2017-02-06?16:26??excercise\ch10\ex10_2\cart.h
?????文件?????????423??2017-02-06?19:00??excercise\ch11\ex11_4\client.cpp
?????文件?????????486??2017-02-06?19:04??excercise\ch11\ex11_5\client.cpp
?????文件?????????542??2017-02-06?19:10??excercise\ch12\ex12_3\client.cpp
?????文件??????????54??2016-09-02?18:47??excercise\ch4\data.txt
?????文件????????1833??2017-02-06?19:08??excercise\ch11\ex11_sikaoti3\deList.h
?????文件????????1277??2017-02-06?19:08??excercise\ch11\ex11_sikaoti3\delistfunc.h
?????文件?????????264??2016-07-28?14:52??excercise\ch2\ex2_5.cpp
?????文件?????????490??2016-07-28?14:58??excercise\ch2\ex2_6.cpp
?????文件?????????461??2016-07-28?14:52??excercise\ch2\ex2_7.cpp
?????文件?????????271??2016-07-28?15:01??excercise\ch2\ex2_8.cpp
?????文件?????????442??2016-07-28?17:42??excercise\ch3\ex3_1.cpp
?????文件?????????595??2016-07-28?17:49??excercise\ch3\ex3_2.cpp
?????文件?????????606??2016-07-28?17:55??excercise\ch3\ex3_3.cpp
?????文件????????1356??2016-07-28?18:13??excercise\ch3\ex3_4.cpp
?????文件?????????499??2016-07-28?18:21??excercise\ch3\ex3_5.cpp
?????文件?????????519??2016-07-28?18:28??excercise\ch3\ex3_6.cpp
?????文件?????????714??2016-07-28?18:38??excercise\ch3\ex3_7.cpp
?????文件?????????581??2016-07-28?18:44??excercise\ch3\ex3_8.cpp
?????文件?????????692??2016-07-28?18:52??excercise\ch3\ex3_9.cpp
?????文件?????????835??2016-07-28?19:41??excercise\ch3\ex3_10.cpp
?????文件?????????801??2016-07-28?19:49??excercise\ch3\ex3_11.cpp
?????文件?????????930??2016-07-28?20:01??excercise\ch3\ex3_12.cpp
?????文件?????????354??2016-07-28?19:09??excercise\ch3\ex3_13.cpp
?????文件?????????369??2016-07-28?19:21??excercise\ch3\ex3_14.cpp
?????文件?????????323??2016-07-28?19:11??excercise\ch3\ex3_15.cpp
?????文件?????????364??2016-07-28?19:12??excercise\ch3\ex3_16.cpp
............此處省略127個文件信息