项目4

#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：