组合类练习.md

组合类练习

总代码

将求两直线的夹角函数定义在了类体内部，将求两点距离的函数定义在了外部，作为独立的函数

#include<iostream>
#include<cmath>
using namespace std;

class Point{
private:
	double X,Y;
public:
	Point(double x, double y){
		X=x;
		Y=y;
	}
	Point(){
		X=0;
		Y=0;
	}
	double getPointX(){
		return X;
	}
	double getPointY(){
		return Y;
	}
};

class Line{
private:
	Point p1,p2;
public:
	Line(Point P1,Point P2){
		p1=P1;
		p2=P2;
	}
	double angle(Line l){
		double ang;
		double tanang,k1,k2;
		k1=(p1.getPointY()-p2.getPointY())*1.0/(p1.getPointX()-p2.getPointX());
		k2=(l.p1.getPointY()-l.p2.getPointY())*1.0/(l.p1.getPointX()-l.p2.getPointX());
		tanang=(k1-k2)/(1+k1*k2);
		ang=atan(tanang);
		return ang;
	}
};
double dis(Point a,Point b){
	double d;
	d=sqrt(pow(a.getPointX()-b.getPointX(),2)+pow(a.getPointY()-b.getPointY(),2));
	return d;
}
int main()
{
	Point a(1,1),b(2,2);
	cout<<dis(a,b)<<endl;
	Line l1(a,b);
	Point c(3,5),d(4,7);
	Line l2(c,d);
	cout<<l1.angle(l2)<<endl;

	return 0;
}

定义点类

class Point{
private:
	double X,Y;
public:
	Point(double x, double y){
		X=x;
		Y=y;
	}
	Point(){
		X=0;
		Y=0;
	}
	double getPointX(){
		return X;
	}
	double getPointY(){
		return Y;
	}
};

定义直线类(含求夹角函数)

class Line{
private:
	Point p1,p2;
public:
	Line(Point P1,Point P2){
		p1=P1;
		p2=P2;
	}
	double angle(Line l){
		double ang;
		double tanang,k1,k2;
		k1=(p1.getPointY()-p2.getPointY())*1.0/(p1.getPointX()-p2.getPointX());
		k2=(l.p1.getPointY()-l.p2.getPointY())*1.0/(l.p1.getPointX()-l.p2.getPointX());
		tanang=(k1-k2)/(1+k1*k2);
		ang=atan(tanang);
		return ang;
	}
};

求距离函数

double dis(Point a,Point b){
	double d;
	d=sqrt(pow(a.getPointX()-b.getPointX(),2)+pow(a.getPointY()-b.getPointY(),2));
	return d;
}