点到直线的距离

#include<iostream.h>
#include<math.h>
class cpoint
{
    int x,y;
public:
	cpoint(int i,int j)
	{
		x=i;
		y=j;
	}
	friend int distance()


};
class line
{
	int c,d,e;
public:
	line(int a1,int b1,int c1)
	{
		c=a1;
		d=b1;
		e=c1;
	}
	friend int distance()

};

int distance()
{
	cpoint l;
	line t;
	return fabs(t.c*l.x+t.d*l.y+t.e)/sqrt(t.c*t.c+t.d*t.d);
}
void main()
{
	int x1,y1,c1,d1,e1;
	cout<<"请输入点的横纵坐标"<<endl;
	cin>>x1>>y1;
	cout<<"请输入直线ax+by+c=0的三个系数"<<endl;
	cin>>c1>>d1>>e1;
	cpoint cpoint1(x1,y1);
	line line1(c1,d1,e1);
	cout<<"此点到此直线的距离为"<<distance()<<endl;
}