T9 - zad.1.

#include <iostream>
#include <cmath>

class Vektor3d
{
    double x, y, z;
    public:
     void Postavi(double x, double y, double z)
     {
         Vektor3d::x = x;
         Vektor3d::y = y;
         Vektor3d::z = z;
     }

     void Ocitaj(double &x, double &y, double &z) const
     {
         x = Vektor3d::x;
         y = Vektor3d::y;
         z = Vektor3d::z;
     }

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

     double DajX() const { return x;}

     double DajY() const { return y;}

     double DajZ() const { return z;}

     double DajDuzinu() const
     {
         return std::sqrt(x*x + y*y + z*z);
     }

     Vektor3d &PomnoziSaSkalarom(double s)
     {
         x*= s;
         y*= s;
         z*= s;
     }

     void SaberiSa(const Vektor3d &v)
     {
    koordinate[0]+= v.koordinate[0];
    koordinate[1]+= v.koordinate[1];
    koordinate[2]+= v.koordinate[2];
    }

     friend Vektor3d ZbirVektora(const Vektor3d &v1,const Vektor3d &v2);

     void PostaviX(double x){ Vektor3d::x=x;}

     void PostaviY(double y){ Vektor3d::y=y;}

     void PostaviZ(double z){ Vektor3d::z=z;}
};

Vektor3d ZbirVektora (const Vektor3d &v, const Vektor3d &v2)
{
    Vektor3d v3;
    v3.x=v.x+v2.x;
    v3.y=v.y+v2.y;
    v3.z=v.z+v2.z;
    return v3;
}

int main()
{
    Vektor3d vektor,vektor2, vektor3;
    vektor.Postavi(2,3,4);
    vektor.Ispisi();
    std::cout<<std::endl;
    vektor.PostaviX(6);
    vektor.Ispisi();
    std::cout<<std::endl<<vektor.DajX()<<std::endl;
    vektor2.Postavi(4,5,6);
    vektor2.Ispisi();
    std::cout<<std::endl;
    vektor.Ispisi();
    vektor3=ZbirVektora(vektor, vektor2);
    vektor3.Ispisi();

return 0;
}