封装小例子——点和圆

  • 案例描述：判断点和圆的位置

示例：

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#include <iostream>
using namespace std;
//圆类：
//半径长度、圆心坐标
class Circle {
private:
	double c_r;//半径长度  可读可写
	double c_x;//圆心横坐标 可读可写
	double c_y;//圆心纵坐标 可读可写
public:
	//获取半径长度
	double getC_r() {
		return c_r;
	}
	//设置圆的半径
	void setC_r(double R) {
		c_r = R;
	}
	//获取圆心横坐标
	double getC_x() {
		return c_x;
	}
	//设置原坐标
	void setC_x(double x) {
		c_x = x;
	}
	//获取圆心纵坐标
	double getC_y() {
		return c_y;
	}
	//设置纵坐标
	void setC_y(double y) {
		c_y = y;
	}
};
//点类
//坐标 可读可写
class point {
private:
	double p_x;
	double p_y;
public:
	//获取圆心横坐标
	double getP_x() {
		return p_x;
	}
	//设置原坐标
	void setP_x(double x) {
		p_x = x;
	}
	//获取圆心纵坐标
	double getP_y() {
		return p_y;
	}
	//设置纵坐标
	void setP_y(double y) {
		p_y = y;
	}
};
void RalationOf_PC(Circle &c,point &p) {
	int dist = pow(c.getC_x() - p.getP_x(), 2) + pow(c.getC_y() - p.getP_y(), 2);
	//cout << "点到圆的距离的平方为：" << dist << endl;
	if (dist > pow(c.getC_r(),2)) {
		cout << "点在圆外" << endl;
	}
	if (dist < pow(c.getC_r(), 2)) {
		cout << "点在圆内" << endl;
	}
	if (dist == pow(c.getC_r(), 2)) {
		cout << "点在圆上" << endl;
	}
}
int main() {
	Circle c;
	c.setC_r(2);
	c.setC_x(1);
	c.setC_y(0);
	point p;
	p.setP_x(3);
	p.setP_y(0);
	RalationOf_PC(c, p);
	return 0;
}

运行结果：

1
点在圆上