5

#include <iostream>
#include <cmath>

using namespace std;



class point
{
    double tab[3];

    friend istream & operator >> (istream &, point &);

public:

    point()
    {
        for(unsigned i=0; i<3; i++)
            tab[i]=0;
    }

    // x jest referencja do tablicy 3 elementowej
    point(const double (&x)[3])
    {
        tab[0] = x[0];
        tab[1] = x[1];
        tab[2] = x[2];
    }

    point(const double &x, const double &y, const double &z)
    {
        tab[0] = x;
        tab[1] = y;
        tab[2] = z;
    }

   const double & operator [] (const unsigned &i) const
   {
       if (i>2)
       {
           cout << "POZA ZAKRESEM!!!";
       }

        return tab[i];
   }


   const double distance(const point &p) const
   {
       return( sqrt( (tab[0]-p[0])*(tab[0]-p[0])  + (tab[1]-p[1])*(tab[1]-p[1]) + (tab[2]-p[2])*(tab[2]-p[2])  ));
   }

    // dodawanie jako metoda
   const point operator + (const point &p) const
   {
        return point(tab[0]+p[0], tab[1]+p[1], tab[2]+p[2]);
   }

    // mnozenie , te moze byc jako metoda
    const point operator * (const double &P)
    {
        return point(tab[0]*P, tab[1]*P, tab[2]*P);
    }

    // porownywanie jako metoda
    bool operator == (const point &p)
    {
        double eps = 1e-10;

        if(abs(this->distance(point()) - p.distance(point())) < eps)
            return true;
        return false;
    }


};

//odejmowanie jako niemetoda
const point operator - (const point &l, const point &p)
{
    return point(l[0]-p[0], l[1]-p[1], l[2]-p[2]);
}


// mnozenie ( z lewej strony elelement nienalezacy do klasy wiec nie moze to byc metoda)
const point operator * (const double & L, const point &p)
{
    return point(L*p[0], L*p[1], L*p[2]);
}

// MUSI BYC TU, BO LEWY ARGUMENT << NIE JEST ELEMENTEM KLASY, NIE TRZEBA ZAPRZYJAZANIAC BO MAMY METODY DOSTEPOWE []
ostream & operator << (ostream &out, const point &p)
{
    out << p[0] << " " << p[1] << " " << p[2];
    return out;
}

// musialem zaprzyjaznic bo na metodach dostepowych [] nie dzialalo.
istream & operator >> (istream &in, point &p)
{
    in >> p.tab[0] >> p.tab[1] >> p.tab[2];
    return in;
}



bool operator < (const point &l, const point &p)
{
    if (l.distance(point()) < p.distance(point()))
        return true;

    return false;
}


int main()
{
    double x[2][3] = {{1.0, 1.0, 1.0},{1.0, 2.0, 3.0}};

    point p1(x[0]), p2(x[1]);

    const point p3(0.4, 0.2, 0.1);

    cout << p1 << ", " << p2 << '\n';

    cout << p1.distance(point()) << ", "<< p3.distance(p1) << '\n';

    cout << p1 + p2 << ", " << p1 - p3 << '\n';

    cout << 3.14 * p2 << ", " << p2 * 3.14 << '\n';

    cout << (p1 < p3) << ", " << (p1 == point(1.0000000001, 1.0, 1.0)) << '\n';

    cin >> p1;
    cout << p1 << '\n';


}