oops exp4 abc-rp

#include<iostream.h>
class ABC;
class XYZ
{
    int a;
public :
    friend void max(XYZ,ABC);
};

class ABC
{
    int b;
public:
    friend void max(XYZ,ABC);
};

void max(XYZ p,ABC q)
{
    cout<<"enter two values to find the max:\n";
    cin>>p.a>>q.b;
    if(p.a>=q.b)
        cout<<"the greatest is "<<p.a<<endl;
    else
        cout<<"the greatest is "<<q.b<<endl;
}

int main()
{
    XYZ q;
    ABC w;
    max(q,w);
    return 0;
}

#include<iostream.h>
class ABC;
class XYZ
{
    int a;
public :
    friend void max(XYZ,ABC);
};

class ABC
{
    int b;
public:
    friend void max(XYZ,ABC);
};

void max(XYZ p,ABC q)
{
    int avg;
    cout<<"enter two values to find the average:\n";
    cin>>p.a>>q.b;
    avg=(p.a+q.b)/2;
    cout<<"the average of "<<p.a<<" and "<<q.b<<" is "<<avg<<endl;
}

int main()
{
    XYZ q;
    ABC w;
    max(q,w);
    return 0;
}

#include<iostream.h>
class ABC;
class XYZ
{
    int a;
public :
    friend void max(XYZ,ABC);
};

class ABC
{
    int b;
public:
    friend void max(XYZ,ABC);
};

void max(XYZ p,ABC q)
{
    int t=0;
    cout<<"enter two values to swap:\n";
    cin>>p.a>>q.b;
    cout<<"values before swapping are a= "<<p.a<<" b= "<<q.b<<endl;
    t=p.a;
    p.a=q.b;
    q.b=t;
    cout<<"values after swapping are a= "<<p.a<<" b= "<<q.b<<endl;
}

int main()
{
    XYZ q;
    ABC w;
    max(q,w);
    return 0;
}