Ambiguity in Inheritance Explained in C++

#include <iostream.h>

#include <conio.h>

class base

{

      public:

      int i;

};

// derived1 inherits base.

class derived1 : public base

{

      public:

      int j;

};

// derived2 inherits base.

class derived2 : public base

{

      public:

      int k;

};

/* derived3 inherits both derived1 and derived2.

This means that there are two copies of base

in derived3! */

class derived3 : public derived1, public derived2

{

      public:

      int sum;

};

int main()

{

      clrscr();

      derived3 ob;

      ob.i = 10; // this is ambiguous, which i???

      ob.j = 20;

      ob.k = 30;

      // i ambiguous here, too

      ob.sum = ob.i + ob.j + ob.k;

      // also ambiguous, which i?

      cout << ob.i << " ";

      cout << ob.j << " " << ob.k << " ";

      cout << ob.sum;

      getch();

      return 0;

}