Need help with this question in c++.

The skeleton is shown below which you can copy and paste and the input is shown along with the desired output.

Implement the RuntimeException Super-class to provide error messages for possible exceptions that could be given by any of the function names marked by throw" in the linked list class interface below:

class RuntimeException {

private:

string errorMsg;

public:

RuntimeException (const string& err ){ errorMsg = err ;}

string getMessage () const {return errorMsg ;}

};

class LinkedListEmpty : public RuntimeException {

public:

LinkedListEmpty (const string& err) : RuntimeException (err) { }

};

template

class Node{

public:

E elem;

Node* next;

};

template

class LinkedList {

public:

LinkedList ();

~ LinkedList ();

bool isEmpty () const;

const E& front () const throw( LinkedListEmpty );

const E& back () const throw( LinkedListEmpty );

void addFront (const E& e);

void removeFront () throw( LinkedListEmpty );

void addBack(const E& s);

void removeBack () throw( LinkedListEmpty );

friend ostream& operator << (ostream& out , const LinkedList & obj ){

Node * temp = obj.head;

if(temp == NULL ){ out << "[]"; return out ;}

out << "[";

while(temp != NULL ){

out << temp ->elem;

if(temp ->next != NULL ){ out << "] --> [";}

temp = temp ->next;

}

out << "]";

return out;

}

private:

Node * head;

};

Input Main:

int main(void){

LinkedList * myList = new LinkedList ();

cout << *myList << endl;

//Adding to the front

cout << myList ->isEmpty () << endl;

myList ->addFront("Gandalf");

cout << *myList << endl;

myList ->addFront("Aragorn");

cout << *myList << endl;

myList ->addFront("Legolas");

cout << *myList << endl;

cout << "Front element: \t"<< myList ->front () << endl;

cout << "Back element: \t"<< myList ->back () << endl;

//Removing from the front

myList -> removeFront ();

cout << *myList << endl;

myList -> removeFront ();

cout << *myList << endl;

myList -> removeFront ();

cout << *myList << endl;

//Should be able to handle this

myList -> removeFront ();

//Adding to the back

myList ->addBack("Gollum");

cout << *myList << endl;

myList ->addBack("Bilbo Baggins");

cout << *myList << endl;

myList ->addBack("Saruman");

cout << *myList << endl;

cout << "Front element: \t"<< myList ->front () << endl;

cout << "Back element: \t"<< myList ->back () << endl;

//Removing from the back

myList -> removeBack ();

cout << *myList << endl;

myList -> removeBack ();

cout << *myList << endl;

myList -> removeBack ();

cout << *myList << endl;

//Should be able to handle this

myList -> removeBack ();

cout << *myList << endl;

return 0;

}

Program Output:

1

[Gandalf]

[Aragorn] --> [Gandalf]

[Legolas] --> [Aragorn] --> [Gandalf]

Front element: Legolas

Back element: Gandalf

[Aragorn] --> [Gandalf]

[Gandalf]

[]

Removing the front of an empty linked list

[Gollum]

[Gollum] --> [Bilbo Baggins]

[Gollum] --> [Bilbo Baggins] --> [Saruman]

Front element: Gollum

Back element: Saruman

[Gollum] --> [Bilbo Baggins]

[Gollum]

[]

Removing the back of an empty linked list

[]