C++简单的类

#include"pch.h"
#include<math.h>
#include<iostream>
using namespace std;
class vector
{
protected:
	float x[2];
public:
	vector()
	{
		for (int i = 0; i < 2; i++)
			x[i] = 0;
	}
	vector(float *a, int n)
	{
		for (int i = 0; i < n; i++)
			x[i] = a[i];
	}
	float* point() { return x; }
	virtual float distance(vector &a, vector&b, int n)
	{
		float sum = 0;
		float *ap, *bp;
		ap = a.point();
		bp = b.point();
		for (int i = 0; i < n; i++)
			sum += pow(ap[i] - bp[i], 2);
		return sqrt(sum);
	}
	~vector()
	{ }
	vector operator-(vector& c)
	{
		vector t;
		for (int i = 0; i < 2; i++)
			t.x[i] = x[i] - c.x[i];
		return t;
	}
	float operator*(vector& c)
	{
		float t = 0;
		for (int i = 0; i < 2; i++)
			t += x[i] * c.x[i];
		return t;
	}
	void operator = (vector c)
	{
		for (int i = 0; i < 2; i++)
			x[i] = c.x[i];
	}
	void show (int i)
	{
		cout << "第" << i << "个向量" << "(";
		for (int n = 0; n < 2; n++)
			cout << x[n] << ",";
		cout << ")" ; 
	}
};
class vector2 :public vector
{
public:
	vector2 ()
	{
		for (int i = 0; i < 2; i++)
			x[i] = 0;
	}
	vector2 (float *a, int n)
	{
		for (int i = 0; i < n; i++)
			x[i] = a[i];
	}
	float* point() { return x; }
	float distance(vector &a, vector &b, int n)
	{
		float sum = 0;
		float *ap, *bp;
		ap = a.point();
		bp = b.point();
		for (int i = 0; i < n; i++)
			sum += fabs(ap[i] - bp[i]);
		return sum;
	}
};
int main()
{
	float a[2] = { 1,2 }, b[2] = { 3,4 };
	vector va(a, 2);
    vector vb(b, 2);
	va.show(1); 
	vb.show(2);
	vector v3; 
	v3 = va - vb;
    v3.show(3);
	float x;
	x = va * vb;
	cout << "两向量的数量积：" << x << endl;
	vector *f1;
	float r;
	f1 = &va;
	r = f1->distance(va, vb, 2);
	cout <<"欧式距离为："<< r << endl;
	vector2 *f2;
	vector2 a2;
	f2 = &a2;
	r = f2->distance(va, vb, 2);
	cout<<"一范距离为："<< r << endl;
	return 0;
}