#include <iostream>

class Vector
{
public:
    float x,y,z;
    Vector(): x(0),y(0),z(0)
    {
    }

    Vector(float _x, float _y, float _z) : x(_x),y(_y),z(_z)
    {
    }

    void sum(const Vector& v, const Vector& w)
    {
        x = v.x + w.x;
        y = v.y + w.y;
        z = v.z + w.z;
    }

    Vector sum(const Vector& v) const
    {
        return Vector(x + v.x, y + v.y, z + v.z);
    }

    Vector operator +(const Vector& v) const
    {
        return Vector(x + v.x, y + v.y, z + v.z);
    }

    Vector operator *(float a) const
    {
        return Vector(x * a, y * a, z * a);
    }

    Vector operator-() const{
        return Vector (-x, -y,-z);
    }

    void print() const
    {
        std::cout << "(" << x << ", " << y << ", " << z << ")" << std::endl;
    }
};

Vector mix (const Vector& a, const Vector& b, float t){
    return a*(1-t) + b*t;
}

int main()
{
    std::cout << "Hello World!" << std::endl;
    Vector v;
    v.x = 4;
    v.y = -5;
    v.z = 0.5f;

    Vector w(1, -2, 0.3f);

    Vector r = v + w;
    Vector t = v.operator+(w);
    r.print();

    r = -r;
    r.print();
    Vector mv = mix(v,-v,0.5f);
    mv.print();
    return 0;
}