Please help with explanations...thank you.

Problem. Read the C++ code below, and answer the questions. 1 #include

2 using namespace std ;

3

4 class BaseOp {

5 public :

6 virtual void increase( int ) = 0;

7 virtual void decrease( int ) = 0; 8 int getVal( void ) { return value ; }

9 BaseOp( void ) { value = 0; }

10 protected :

11 int value ;

12 };

13

14 class IncCube : public virtual BaseOp {

15 public :

16 void increase( int n ) {

17 value = value + n n n ;

18 }

19 IncCube( void ) { value = value + 5; }

20 };

21

22 class DecSquare : public virtual BaseOp {

23 public :

24 void decrease( int n ) {

25 value = value n n ;

26 }

27 DecSquare( void ) { value = value + 5; }

28 };

29

30 class MyOp : public IncCube , public DecSquare {

31 public :

32 MyOp( void ) { value = value + 5; }

33 };

34

35 int main( int argc , char argv ) {

36 MyOp myoper ;

37 myoper . increase( 13 ) ;

38 myoper . decrease( 14 ) ;

39 cout << myoper . getVal () << endl ;

40 return 0;

41 }

(a). For the four classes weve dened, how many of them can be instantatiated? List all that can be done.

(b). Whats the nal output of the preceding program?