класс

#include <iostream>
#include <cmath>

using namespace std;
class Vector
{
private: int x, y;

public: Vector() : x(0), y(0)
{

}
		Vector(int x, int y) :x(x), y(y)
		{
		}

		void ShowData()
		{
			cout << "(" << x << "," << y << ")";
			cout << endl;
		}
		double GetDlina()
		{
			return sqrt(x*x + y*y);
		}
		bool operator== (const Vector &v1)
		{
			return (x == v1.x && y == v1.y);
		}
		Vector add(Vector d)
		{
			Vector result;
			result.x = x + d.x;
			result.y = y + d.y;
			return result;
		}

		Vector sub(Vector d)
		{
			Vector result;
			result.x = x - d.x;
			result.y = y - d.y;
			return result;
		}

		double scal(Vector right)
		{
			return x*right.x + y*right.y;
		}

};
int main()
{
	int x, y, x2, y2;

	cout << "Enter x && y=";
	cin >> x >> y;
	Vector v(x, y);

	cout << "Enter x2 && y2=";
	cin >> x2 >> y2;
	Vector v1(x2, y2);

	v.ShowData();
	v1.ShowData();
	cout << v.GetDlina() << endl;
	cout << v1.GetDlina() << endl;
	cout << v.scal(v1) << endl;
	system("pause");
	return 0;
}