新的开始c++

今天开始学习c++,还是有点不适应,慢慢来吧.

先写个类的初学,判断点是否在圆内

#ifndef __CIRCLE_H__
#define __CIRCLE_H__

#include "Point.h"

class circle
{
public:
	void setCircle(int r, int x, int y);
	bool inCircle(point &p);
private:
	int c_r;
	point c_p; 
};

#endif

#ifndef  __POINT_H__
#define __POINT_H__

class point
{
public:
	void setXY(int x,int y);     //设置点
	int lenP(point &p);		  //求点与点之间距离的平方
private:
	int p_x;
	int p_y;
};

#endif

#include "Circle.h"

//设置一个圆
void circle::setCircle(int r, int x, int y)
{
	c_r = r;
	c_p.setXY(x,y);
}
//判断点在不在圆内
bool circle::inCircle(point &p)
{
	if( c_p.lenP(p) <= c_r*c_r)
		return true;
	else 
		return false;
}

#include"Point.h"

void point::setXY(int x,int y)
{
	p_x = x;
	p_y = y;
}

int point::lenP(point &p)
{
	int len = (p_x - p.p_x) * (p_x - p.p_x) + (p_y - p.p_y) *(p_y - p.p_y) ;
	return len;
}

#include <iostream>
#include "Circle.h"
#include "Point.h"

using namespace std;

int main()
{
	point p;
	circle c;

	p.setXY(10,20);
	c.setCircle(9,20,20);

	if(c.inCircle(p))
	{
		cout<< "在圆内"<<endl;
	}
	else 
	{
		cout<< "在圆外"<<endl;
	}

	system("pause");
	return 0;
}