diamond problem in c++ code example

Example 1: solution of diamond problem in c++

Virtual inheritance solves the classic “Diamond Problem”.
  It ensures that the child class gets only a single instance of the common base class.

Example 2: Diamond inheritance

The "diamond problem" (sometimes referred to as the "Deadly Diamond of Death") is an ambiguity that arises when two classes B and C inherit from A, and class D inherits from both B and C
If there is a method in A that B and C have overridden, and D does not override it, then which class of the method does D inherit: that of B, or that of C?

Example 3: c++ multiple inheritance diamond problem

class Parent;
class a : virtual public Parent; //add virtual
class b : virtual public Parent; //add virtual
class c : public a, public b;