In project $6,$ you defined an ADT FrontList, which restricts insertions, removals, and retrievals to the first item in the list. A class definition for the ADT FrontList is provided below:

template

class FrontList

$\{$

public:

$//$ Sees whether this list is empty.

virtual bool isEmpty$()$ const $=0$;

$//$ Gets the current number of entries in this list.

virtual int getLength$()$ const $=0$;

$//$ Inserts an entry into the front of this list

virtual bool insert$($const ItemType& newEntry$)=0$;

$//$ Removes the entry at front of this list.

virtual bool remove$()=0$;

$//$ Removes all entries from this list.

virtual void clear$()=0$;

$//$ Gets the entry at the front of this list.

virtual ItemType getEntry$()$ const $=0$;

$//$ Replaces the entry at front of this list.

virtual void setEntry$($ItemType& newEntry$)=0$;

private:

$//$data members here

$......$

$\}$;

Question $5(10$ points$)$

Define the ADT stack as a derived class from the ADT FrontList using private inheritance $($AsA relationship$).$ Which of the following answers is the correct class definition?

Question $5$ options:

a$)$

template

class StackAsA : private FrontList

$\{$

Public:

StackAsA $()$;

StackAsA $($const StackAsA & aStack$)$;

virtual ~ StackAsA $()$;

bool isEmpty$()$ const;

bool push$($const ItemType& newItem$)$;

bool pop$()$;

ItemType peek$()$ const throw$($PrecondViolatedExcep$)$;

$\}$;

b$)$

template

class StackAsA

$\{$

private:

FrontList fList;

Public:

StackAsA $()$;

StackAsA $($const StackAsA & aStack$)$;

virtual ~ StackAsA $()$;

bool isEmpty$()$ const;

bool push$($const ItemType& newItem$)$;

bool pop$()$;

ItemType peek$()$ const throw$($PrecondViolatedExcep$)$;

$\}$;

c$)$

template

class StackAsA : private FrontList

$\{$

Private:

Node$*$ topPtr;

Public:

StackAsA $()$;

StackAsA $($const StackAsA & aStack$)$;

virtual ~StackAsA$()$;

bool isEmpty$()$ const;

bool push$($const ItemType& newItem$)$;

bool pop$()$;

ItemType peek$()$ const throw$($PrecondViolatedExcep$)$;

$\}$;

d$)$

template

class StackAsA: private FrontList

$\{$

private:

FrontList fList;

Public:

StackAsA $()$;

StackAsA $($const StackAsA & aStack$)$;

virtual ~ StackAsA $()$;

bool isEmpty$()$ const;

bool push$($const ItemType& newItem$)$;

bool pop$()$;

ItemType peek$()$ const throw$($PrecondViolatedExcep$)$;

$\}$;