// fewrfwer.cpp: определяет точку входа для консольного приложения.
//



#include "stdafx.h"
#include <iostream>
#include <conio.h>
#include <math.h>


using namespace std;

class Vector
{
private:
    double x, y;
public:
    Vector()
    {
        x = 0;
        y = 0;
    }
    Vector(double a, double b)
    {
        x = a;
        y = b;
    }
    double PrX()
    {
        return x;
    }
    double PrY()
    {
        return y;
    }
    double Lenght()
    {
        return sqrt(x*x + y*y);
    }
    friend ostream& operator<<(ostream& o, const Vector& v);
    friend Vector operator+(Vector v1, Vector v2);
    friend Vector operator-(Vector v1, Vector v2);
    friend Vector operator*(double k, Vector v2);
};

// v1.dot(v2)   -> v1.x*v2.x + v1.y*v2.y = |v1|*|v2|*cos(angle|

// x1*y2 - y1*x2 = |v1|*|v2|*sin(angle)
// atan2(cos, sin) = {-pi, pi)
// v1.angle(v2) ->

Vector operator+(Vector v1, Vector v2)
{
    return Vector(v1.x + v2.x, v1.y + v2.y);
}

Vector operator-(Vector v1, Vector v2)
{
    Vector res;
    res.x = v1.x - v2.x;
    res.y = v1.y - v2.y;
    return res;
}

Vector operator*(double k, Vector v2)
{
    Vector res;
    res.x = k*v2.x;
    res.y = k*v2.y;
    return res;
}

ostream& operator<<(ostream& o, const Vector& v)
{
    o << '(' << v.x << ", " << v.y << ')';
    return o;
}

//class SuperVector : public Vector
//{
//public:
//  SuperVector() : Vector()
//  {}
//
//  SuperVector(0, 0) : Complex(0, 0)
//
//};
int _tmain(int argc, _TCHAR* argv[])
{
    Vector v1 = Vector();
    Vector v2 = Vector(3,4);
    Vector v3 = Vector(-2,1);
    double k = -12;
    cout << "v1 = " << v1 << ", v2 = " << v2 << ", v3 = " << v3 << '\n';
    cout << "v1 + v2 = " << v1 + v2 << ", v2 + v3 = " << v2 + v3 << ", v1 + v2 + v3 = " << v1 + v2 + v3 << '\n';
    cout << "v1 - v2 = " << v1 - v2 << ", v2 - v3 = " << v2 - v3 << ", v1 - v2 - v3 = " << v1 - v2 - v3 << '\n';
    cout << "k*v2 = " << k*v2 << '\n';
    cout << "Proectia na osi X vectora v2: " << v2.PrX() << ", Proectia na osi Y vectora v3: " << v3.PrY() << '\n';
    cout << "Dlina vectora v2: " << v2.Lenght();
    getch();
}