（用c++编写程序）输入平面直角坐标系中一点的坐标（x,y），判断改点是在那个象限中或那一条坐标轴上

Answer 1

include "math.h"

class point
{
public:
float x;
float y;

//构造函数
point(float x,float y)
{
this->x=x;
this->y=y;
}
};

class line
{
float a;
float b;
float c;

public:
//构造函数
line(float a,float b,float c)
{
this->a=a;
this->b=b;
this->c=c;
}

float getDistance(point p)
{
float x,y;
x=p.x;
y=p.y;
return fabs(a*x+b*y+c)/sqrt(a*a+b*b);
}
};

void main()
{
float x,y;
cout<<"请输入点的X坐标:";
cin>>x;
cout<<"请输入点的Y坐标:";
cin>>y;
point p(x,y);

float a,b,c;
cout<<"请输入a:";
cin>>a;
cout<<"请输入b:";
cin>>b;
cout<<"请输入c:";
cin>>c;
line l(a,b,c);
cout<<"点到直线的距离为:"<<l.getDistance(p)<<endl;
}