Перегрузка контсруктора

#include <iostream>
#include <math.h>
#include <conio.h>
#include <iomanip>
using namespace std;
struct koord{double x,y,z;};
class vektors{
    double x1,y1,z1,x2,y2,z2;
public:  vektors(double x1,double y1,double z1,double x2,double y2,double z2);
        ~vektors(); void sl(double x1, double y1, double z1, double x2,double y2,double z2);
        void vich(double x1, double y1, double z1, double x2,double y2,double z2);
        void proiz(double x1, double y1, double z1, double x2,double y2,double z2);
        void dlin(double x1, double y1, double z1, double x2,double y2,double z2);
        void cosin(double x1, double y1, double z1, double x2,double y2,double z2);
};
vektors::vektors(double x1,double y1,double z1,double x2,double y2,double z2)
{cout<<"В конструкторе\n";
x1=x1; y1=y1; z1=z1; x2=x2; y2=y2; z2=z2;};
vektors::~vektors()
{cout<<"В деструкторе";getch();};
void vektors::sl(double x1, double y1, double z1, double x2,double y2,double z2)
{double x, y, z;
x=x1+x2;
y=y1+y2;
z=z1+z2;
cout<<"Результат сложения: С("<<x<<","<<y<<","<<z<<")\n";};
void vektors::vich(double x1, double y1, double z1, double x2,double y2,double z2)
{double x,y,z;
x=x1-x2;
y=y1-y2;
z=z1-z2;
cout<<"Результат вычитания: С("<<x<<","<<y<<","<<z<<")\n";};
void vektors::proiz(double x1, double y1, double z1, double x2,double y2,double z2)
{double ps,pvx,pvy,pvz;
ps=x1*x2+y1*y2+z1*z2;
cout<<"Скалярное произведение="<<ps<<'\n';
pvx=y1*z2-z1*y2;
pvy=z1*x2-x1*z2;
pvz=x1*y2-y1*x2;
cout<<"Векторное произведение: С("<<pvx<<","<<pvy<<","<<pvz<<")\n";
};
void vektors::dlin(double x1, double y1, double z1, double x2,double y2,double z2)
{double dla,dlb;
dla=sqrt(pow(x1,2)+pow(y1,2)+pow(z1,2));
dlb=sqrt(pow(x2,2)+pow(y2,2)+pow(z2,2));
cout<<"Длина вектора А="<<setprecision(4)<<dla<<'\n';
cout<<"Длина вектора B="<<setprecision(4)<<dlb<<'\n';
};
void vektors::cosin(double x1, double y1, double z1, double x2,double y2,double z2)
{double c,u;
c=(x1*x2+y1*y2+z1*z2)/(sqrt(pow(x1,2)+pow(y2,2)+pow(z1,2)*sqrt(pow(x2,2)+pow(y2,2)+pow(z2,2))));
u=acos(c);
cout<<"Cos a="<<setprecision(5)<<c<<'\n';
};
int main()
{setlocale(LC_ALL, "Russian");
    koord v,v1;
    cout<<"Координаты A: \nx ";
    cin>>v.x;
    cout<<"y "; cin>>v.y;
    cout<<"z "; cin>>v.z;
cout<<"\nКоординаты B: \nx ";
cin>>v1.x;
cout<<"y ";
cin>>v1.y;
cout<<"z ";
cin>>v1.z;
cout<<'\n';
vektors perem(v.x,v.y,v.z,v1.x,v1.y,v1.z); 
perem.sl(v.x,v.y,v.z,v1.x,v1.y,v1.z);
perem.vich(v.x,v.y,v.z,v1.x,v1.y,v1.z);
perem.dlin(v.x,v.y,v.z,v1.x,v1.y,v1.z);
perem.cosin(v.x,v.y,v.z,v1.x,v1.y,v1.z);
perem.proiz(v.x,v.y,v.z,v1.x,v1.y,v1.z);
getch();
return 0;
}

vektors() : x1(), y1(), z1(), x2(), y2(), z2() {}

class vektors {
// ...
public:
   vektors() : x1(), y1(), z1(), x2(), y2(), z2() {}
// ...
};

vektors::vektors(double x1,double y1,double z1,double x2,double y2,double z2)
{cout<<"В конструкторе\n";
x1=x1; y1=y1; z1=z1; x2=x2; y2=y2; z2=z2;};

vektors::vektors(){}