圆类

#include <iostream>
using namespace std;
//点类
class Point
{
public:
  //设置x,y 获取x,y
  void SetX(int x)
  {
    p_x = x;
  }
  void SetY(int y)
  {
    p_y = y;
  }
  int GetX()
  {
    return p_x;
  }
  int GetY()
  {
    return p_y;
  }

private:
  int p_x;
  int p_y;
};

//圆类
class Circle
{
public:
  //设置半径
  void SetR(int r)
  {
    c_r = r;
  }
  //获取半径
  int GetR()
  {
    return c_r;
  }
  //设置圆心
  void SetCenter(Point p)
  {
    c_center = p;
  }
  //获取圆心
  Point GetCenter()
  {
    return c_center;
  }
private:
  int c_r; //半径
  Point c_center; //圆心
};

//利用全局函数 判断点和圆的关系
void IsInCircle(Circle c, Point p)
{
  int distance = (c.GetCenter().GetX() - p.GetX()) *
    (c.GetCenter().GetX() - p.GetX()) + 
    (c.GetCenter().GetY() - p.GetY()) * 
    (c.GetCenter().GetY() - p.GetY());
  int r_distance = c.GetR() * c.GetR();
  if (distance == r_distance)
  {
    cout << "点在圆上" << endl;
  }
  else if (distance > r_distance)
  {
    cout << "点在圆外" << endl;

  }
  else
  {
    cout << "点在圆内" << endl;

  }
}

int main()
{
  //实例化点
  Point p;
  p.SetX(10);
  p.SetY(10);
  //实例化圆
  Circle c;
  //设置圆的圆心
  Point c_center;
  c_center.SetX(10);
  c_center.SetY(0);
  c.SetCenter(c_center);
  //设置半径
  c.SetR(10);

  IsInCircle(c,p);
  return 0;
}