Need answer for linked list exam question

this the one of example linked list in full program, but i still cant solve it, hope any people there can help me

this quest wee need to answer on "//" sign only, hope please help me, this like one question it will come out in my exam, this question one of linked list in class classified.

#ifndef H_LinkedListType
#define H_LinkedListType

#include <iostream>
#include <cassert>

using namespace std;

//Definition of the node

template <class type="">
struct nodeType {
    Type info;
    nodeType<type> *link;
};

template <class type="">
class linkedListIterator {
public:
    linkedListIterator();
    //Default constructor
    //Postcondition: current = NULL;

    linkedListIterator(nodeType<type> *ptr);
    //Constructor with a parameter.
    //Postcondition: current = ptr;

    Type operator*();
    //Function to overload the dereferencing operator *.
    //Postcondition: Returns the info contained in the node.

    linkedListIterator<type> operator++();
    //Overload the pre-increment operator.
    //Postcondition: The iterator is advanced to the next
    //               node.

    bool operator==(const linkedListIterator<type>& right) const;
    //Overload the equality operator.
    //Postcondition: Returns true if this iterator is equal to
    //               the iterator specified by right,
    //               otherwise it returns the value false.

    bool operator!=(const linkedListIterator<type>& right) const;
    //Overload the not equal to operator.
    //Postcondition: Returns true if this iterator is not
    //               equal to the iterator specified by
    //               right; otherwise it returns the value
    //               false.

private:
    nodeType<type> *current; //pointer to point to the current
    //node in the linked list
};

template <class type="">
linkedListIterator<type>::linkedListIterator() {
    current = NULL;
}

template <class type="">
linkedListIterator<type>::
linkedListIterator(nodeType<type> *ptr) {
    current = ptr;
}

template <class type="">
Type linkedListIterator<type>::operator*() {
    return current->info;
}

template <class type="">
linkedListIterator<type> linkedListIterator<type>::operator++() {
    current = current->link;

    return *this;
}

template <class type="">
bool linkedListIterator<type>::operator==
(const linkedListIterator<type>& right) const {
    return (current == right.current);
}

template <class type="">
bool linkedListIterator<type>::operator!=
(const linkedListIterator<type>& right) const {
    return (current != right.current);
}


//*****************  class linkedListType   ****************

template <class type="">
class linkedListType {
public:
    const linkedListType<type>& operator=
    (const linkedListType<type>&);
    //Overload the assignment operator.

    void initializeList();
    //Initialize the list to an empty state.
    //Postcondition: first = NULL, last = NULL, count = 0;

    bool isEmptyList() const;
    //Function to determine whether the list is empty.
    //Postcondition: Returns true if the list is empty,
    //               otherwise it returns false.

    void print() const;
    //Function to output the data contained in each node.
    //Postcondition: none

    int length() const;
    //Function to return the number of nodes in the list.
    //Postcondition: The value of count is returned.

    void destroyList();
    //Function to delete all the nodes from the list.
    //Postcondition: first = NULL, last = NULL, count = 0;

    Type front() const;
    //Function to return the first element of the list.
    //Precondition: The list must exist and must not be
    //              empty.
    //Postcondition: If the list is empty, the program
    //               terminates; otherwise, the first
    //               element of the list is returned.

    Type back() const;
    //Function to return the last element of the list.
    //Precondition: The list must exist and must not be
    //              empty.
    //Postcondition: If the list is empty, the program
    //               terminates; otherwise, the last
    //               element of the list is returned.

    virtual bool search(const Type& searchItem) const = 0;
    //Function to determine whether searchItem is in the list.
    //Postcondition: Returns true if searchItem is in the
    //               list, otherwise the value false is
    //               returned.

    virtual void insertFirst(const Type& newItem) = 0;
    //Function to insert newItem at the beginning of the list.
    //Postcondition: first points to the new list, newItem is
    //               inserted at the beginning of the list,
    //               last points to the last node in the list,
    //               and count is incremented by 1.

    virtual void insertLast(const Type& newItem) = 0;
    //Function to insert newItem at the end of the list.
    //Postcondition: first points to the new list, newItem
    //               is inserted at the end of the list,
    //               last points to the last node in the list,
    //               and count is incremented by 1.

    virtual void deleteNode(const Type& deleteItem) = 0;
    //Function to delete deleteItem from the list.
    //Postcondition: If found, the node containing
    //               deleteItem is deleted from the list.
    //               first points to the first node, last
    //               points to the last node of the updated
    //               list, and count is decremented by 1.

    linkedListIterator<type> begin();
    //Function to return an iterator at the begining of the
    //linked list.
    //Postcondition: Returns an iterator such that current is
    //               set to first.

    linkedListIterator<type> end();
    //Function to return an iterator one element past the
    //last element of the linked list.
    //Postcondition: Returns an iterator such that current is
    //               set to NULL.

    linkedListType();
    //default constructor
    //Initializes the list to an empty state.
    //Postcondition: first = NULL, last = NULL, count = 0;

    linkedListType(const linkedListType<type>& otherList);
    //copy constructor

    ~linkedListType();
    //destructor
    //Deletes all the nodes from the list.
    //Postcondition: The list object is destroyed.

    void reversePrint() const;

protected:
    int count;   //variable to store the number of
    //elements in the list
    nodeType<type> *first; //pointer to the first node of the list
    nodeType<type> *last;  //pointer to the last node of the list

private:
    void copyList(const linkedListType<type>& otherList);
    //Function to make a copy of otherList.
    //Postcondition: A copy of otherList is created and
    //               assigned to this list.
    void recursiveReversePrint(nodeType<type> *current) const;
};


template <class type="">
bool linkedListType<type>::isEmptyList() const {
    return(first == NULL);
}

template <class type="">
linkedListType<type>::linkedListType() { //default constructor
    first = NULL;
    last = NULL;
    count = 0;
}

template <class type="">
void linkedListType<type>::destroyList() {
    nodeType<type> *temp;   //pointer to deallocate the memory
    //occupied by the node
    while (first != NULL) { //while there are nodes in the list
        temp = first;        //set temp to the current node
        first = first->link; //advance first to the next node
        delete temp;   //deallocate the memory occupied by temp
    }
    last = NULL; //initialize last to NULL; first has already
    //been set to NULL by the while loop
    count = 0;
}

template <class type="">
void linkedListType<type>::initializeList() {
    destroyList(); //if the list has any nodes, delete them
}

template <class type="">
void linkedListType<type>::print() const {
    nodeType<type> *current; //pointer to traverse the list

    current = first;    //set current so that it points to
    //the first node
    while (current != NULL) { //while more data to print
        cout << current->info << " ";
        current = current->link;
    }
}//end print

template <class type="">
int linkedListType<type>::length() const {
    return count;
}  //end length

template <class type="">
Type linkedListType<type>::front() const {
    assert(first != NULL);

    return first->info; //return the info of the first node
}//end front

template <class type="">
Type linkedListType<type>::back() const {
    assert(last != NULL);

    return last->info; //return the info of the last node
}//end back

template <class type="">
linkedListIterator<type> linkedListType<type>::begin() {
    linkedListIterator<type> temp(first);

    return temp;
}

template <class type="">
linkedListIterator<type> linkedListType<type>::end() {
    linkedListIterator<type> temp(NULL);

    return temp;
}

template <class type="">
void linkedListType<type>::copyList
(const linkedListType<type>& otherList) {
    nodeType<type> *newNode; //pointer to create a node
    nodeType<type> *current; //pointer to traverse the list

    if (first != NULL) //if the list is nonempty, make it empty
        destroyList();

    if (otherList.first == NULL) { //otherList is empty
        first = NULL;
        last = NULL;
        count = 0;
    } else {
        current = otherList.first; //current points to the
        //list to be copied
        count = otherList.count;

        //copy the first node
        first = new nodeType<type>;  //create the node

        first->info = current->info; //copy the info
        first->link = NULL;        //set the link field of
        //the node to NULL
        last = first;              //make last point to the
        //first node
        current = current->link;     //make current point to
        //the next node

        //copy the remaining list
        while (current != NULL) {
            newNode = new nodeType<type>;  //create a node
            newNode->info = current->info; //copy the info
            newNode->link = NULL;       //set the link of
            //newNode to NULL
            last->link = newNode;  //attach newNode after last
            last = newNode;        //make last point to
            //the actual last node
            current = current->link;   //make current point
            //to the next node
        }//end while
    }//end else
}//end copyList

template <class type="">
linkedListType<type>::~linkedListType() { //destructor
    destroyList();
}//end destructor

template <class type="">
linkedListType<type>::linkedListType
(const linkedListType<type>& otherList) {
    first = NULL;
    copyList(otherList);
}//end copy constructor

//overload the assignment operator
template <class type="">
const linkedListType<type>& linkedListType<type>::operator=
(const linkedListType<type>& otherList) {
    if (this != &otherList) { //avoid self-copy
        copyList(otherList);
    }//end else

    return *this;
}

#endif

Tags: C++