#include<iostream>
#include<cmath>
using namespace std;
class CPoint
{
private:
double x; // 横坐标
double y; // 纵坐标
public:
CPoint(double xx=0,double yy=0);
double distance(CPoint p) const; // 两点之间的距离(一点是当前点,另一点为参数p)
void input(); //以x,y 形式输入坐标点
};
class CTriangle
{
public:
CTriangle(CPoint &X,CPoint &Y,CPoint &Z):A(X),B(Y),C(Z){} //给出三点的构造函数
void setTriangle(CPoint &X,CPoint &Y,CPoint &Z);//
float perimeter();//计算三角形的周长
float area();//计算并返回三角形的面积
bool isRightTriangle(); //是否为直角三角形
bool isIsoscelesTriangle(); //是否为等腰三角形
private:
CPoint A,B,C; //三顶点
};
int main(){
CPoint num,num1,num2;
CTriangle n(num,num1,num2);
cout<<"输入第一个点";
num.input();
cout<<"输入第二个点";
num1.input();
cout<<"输入第三个点";
num2.input();
n.setTriangle(num,num1,num2);
cout<<"三点构成三角形的情况"<<endl;
cout<<"面积"<<n.area()<<endl;
cout<<"周长"<<n.perimeter()<<endl;
if(n.isRightTriangle())
cout<<"是直角三角形"<<endl;
else
cout<<"不是直角三角形"<<endl;
if(n.isIsoscelesTriangle())
cout<<"是等腰三角形"<<endl;
else
cout<<"不是等腰三角形"<<endl;
return 0;
}
CPoint::CPoint(double xx,double yy){
x=xx;
y=yy;
}
double CPoint::distance (CPoint p)const{
return sqrt(((p.x-x)*(p.x-x)+(p.y-y)*(p.y-y)));
}
void CPoint::input()
{
char ch;
cout<<"请输入坐标点 格式(x,y ):";
while(1)
{
cin>>x>>ch>>y;
if (ch==',') break;
cout<<"输入的数据格式不符合规范,请重新输入\n";
}
}
void CTriangle::setTriangle(CPoint &X,CPoint &Y,CPoint &Z)
{
A=X;
B=Y;
C=Z;
}
float CTriangle::perimeter()
{
double a=B.distance(C),b=C.distance(A),c=A.distance(B);
return (a + b + c);
}//计算三角形的周长
float CTriangle::area(){
double a=B.distance(C),b=C.distance(A),c=A.distance(B);
double s = (a + b + c) / 2;
return sqrt(s * (s - a) * (s - b) * (s - c));
}//计算并返回三角形的面积
bool CTriangle::isRightTriangle(){
double a=B.distance(C),b=C.distance(A),c=A.distance(B);
double max=a;
if(b>max) max=b;
if(c>max) max=c;
if(((max==a)&&(max*max==b*b+c*c))||((max==b)&&(max*max==a*a+c*c))||((max==c)&&(max*max==a*a+b*b)))
return true;
else
return false;
}
bool CTriangle::isIsoscelesTriangle(){
double a=B.distance(C),b=C.distance(A),c=A.distance(B);
if((a=b)||(b=c)||(c=a))
return true;
else
return false;
}
运行结果: