六週任務4.1

#include <iostream>
#include <cmath>

using namespace std;

class CPoint
{
private :
	double x ;
	double y ;

public :
	CPoint( double xx = 0 , double yy = 0 );//構造函數聲明

	double Distance ( CPoint p ) const ;//求兩點距離函數聲明

	void input() ;//按x , y的形式輸入點

	void output() ;//按（x,y)輸出點的值

};

CPoint::CPoint( double xx , double yy )
{
	x = xx ;
	y = yy ;
}

void  CPoint::input()
{
	cout << "按 x , y 的形式輸入座標點" << endl ;
	cin >> x >> y ;
}

void  CPoint::output()
{
	cout<< "點的座標爲：" <<"("<< x <<","<< y <<")"<< endl ;
}

double CPoint::Distance ( CPoint p ) const
{
	double h ;
	h = sqrt ((x - p.x)*(x - p.x) + (y - p.y)*(y - p.y)) ; 
	return h ;
}

class CTriangle

{
public:

    CTriangle(CPoint &x , CPoint &y , CPoint &z ):A(x),B(y),C(z){}//

	void setTriangle (CPoint &x , CPoint &y , CPoint &z );//

	double perimeter(void);//

	double area(void);//

	bool isRightTriangle();//

	bool isIsoscelesTriangle();//

private:

	CPoint A , B , C ;//
};

/*CTriangle:: CTriangle()

{
	A=x ;

	B=y ;

	C=z ;
}*/

double  CTriangle::perimeter(void)

{
	return ( A.Distance(B) + A.Distance(C) + B.Distance(C) ) ;//
}

void  CTriangle::setTriangle (CPoint &x , CPoint &y , CPoint &z )

{
	A.input();
    B.input();
	C.input();
}

double  CTriangle::area(void)

{  
	double s , m ;

	m = ( A.Distance(B) + A.Distance(C) + B.Distance(C) )/2 ;

	s = sqrt ( m * ( m - A.Distance(B) ) * ( m - A.Distance(C) ) * ( m - B.Distance(C) ) ) ;//

	return s ;
}

bool  CTriangle::isRightTriangle()

{
	if ( abs(A.Distance(B)*A.Distance(B)+A.Distance(C)*A.Distance(C)-B.Distance(C)*B.Distance(C))<1e-6||abs( A.Distance(B)*A.Distance(B)+B.Distance(C)*B.Distance(C)-A.Distance(C)*A.Distance(C))<1e-6||abs(A.Distance(C)*A.Distance(C)+B.Distance(C)*B.Distance(C)-A.Distance(B)*A.Distance(B))<1e-6)

		 return true ;
	else 

		return false ;
}

bool  CTriangle::isIsoscelesTriangle()

{
	if((abs(A.Distance(C)*A.Distance(C)-B.Distance(C)*B.Distance(C))<1e-6)||((abs(A.Distance(B)*A.Distance(B)-B.Distance(C)*B.Distance(C))<1e-6)||(abs(A.Distance(B)*A.Distance(B)-A.Distance(C)*A.Distance(C))<1e-6) ))

        return true ;
	else 
		return false ;
}

	int main()

	{
		CTriangle ctr1(CPoint(3,6),CPoint(5,7),CPoint(8,6)) ;

		//ctr1.setTriangle() ;//

		cout<<"該三角形的周長爲："<<ctr1.perimeter()<<"，面積爲："<<ctr1.area()<<endl<<endl;  

                  cout<<"該三角形"<<(ctr1.isRightTriangle()?"是":"不是")<<"直角三角形"<<endl;  

                  cout<<"該三角形"<<(ctr1.isIsoscelesTriangle()?"是":"不是")<<"等腰三角形"<<endl;  

		system ("pause") ;

		return  0 ;
	}

運行結果：

 

感受：最後主函數中的後兩個輸出還有待掌握，原本想運行時輸入三個點，ctr1.setTriangle()  卻出現了“參數不能爲空的錯誤”不理解啊。望老師給予寶貴意見，

 

想在運行時隨意輸入三個點。  呵呵

。謝謝老師啦。呵呵

我要繼續加油！！！！！！！！！！