How can I save the coordinates of the two points a and b in 3D space as follows(using class)

Question

Value a as constructor and coordinates (5,10,2) and value b as setpoint function with coordinates (6,20,5)
I wrote it before:

#include <iostream>

using namespace std;

class point3D
{
public:

int X,Y,Z;
point3D(const int a, const int b, const int c);

int x() const;
int y() const;
int z() const;

void setpoint(int,int,int);
};

point3D::point3D()
{
X=0;
Y=0;
Z=0;
}

point3D::point3D(const int a, const int b, const int c)
{
X=a;
Y=b;
Z=c;
}

int main()
{
point3D p1(5,10,2);
point3D p2;
p2.setpoint(6,20,5);
return 0;
}

Answer 1

First of all thank you so much for correcting my code🙏🏻🙏🏻 it's really help me
And about your question it's a code practice problem that have 4 parts and I get confused because I don't know what to do 🤦🏻‍♀️
For example in a part of that it said that if you put "cout<< point3D::count<<endl;" in the last statement of int main what will be the output? And for access to this static element what do you suggest?
And I don't know what I should do because I don't have any output):