QT计算圆与直线关系

circle.h:

#ifndef CIRCLE_H

#define CIRCLE_H

#include "line.h"

#include "circle.h"

#include<math.h>

class line;

class circle

{

public:

    circle(double xx,double yy,double rr);

    double getX();

    double getY();

    double getR();

    void judge(line &l,circle &c);

private:

    double x,y,r;

};

#endif // CIRCLE_H

line.h:

#ifndef LINE_H

#define LINE_H

#include "line.h"

#include "circle.h"

#include<math.h>

class line

{

public:

    line(double kk,double bb);

    double distant(circle &c);

private:

    double k;

    double b;

};

#endif // LINE_H

circle.cpp:

#include "line.h"

#include "circle.h"

#include<math.h>

#include<QDebug>

circle::circle(double xx,double yy,double rr)

    :x(xx),

      y(yy),

      r(rr)

{

}

double circle::getX()

{

    return x;

}

double circle:: getY()

{

    return y;

}

double circle::getR()

{

    return r;

}

void circle:: judge(line &l,circle &c)

{

    double d=l.distant(c);

    if(d>r)

        qDebug()<<"圆与直线不相交！"<<endl;

    else if(d==r)

        qDebug()<<"圆与直线相切！"<<endl;

    else

        qDebug()<<"圆与直线相交！"<<endl;

}

line .cpp:

#include "line.h"

#include "circle.h"

#include<math.h>

line::line(double kk,double bb)

{

  k=kk;

  b=bb;

}

 double line::distant(circle &c)

 {

       double x=c.getX();

       double y=c.getY();

       double a,f,d;

       a=k*x+b+y;

       f=k*k+1;

       d=sqrt(a/f);

       return d;

 }

main.cpp:

#include <QCoreApplication>

#include "line.h"

#include "circle.h"

#include<math.h>

#include<iostream>

using namespace std;

int main(int argc, char *argv[])

{

    QCoreApplication a(argc, argv);

  circle c(0,0,1);

  line l(1,3);

  c.judge(l,c);

  cout<<"r="<<c.getR()<<endl;

  cout<<"d="<<l.distant(c)<<endl;

  return 0;

    return a.exec();

}