I need help with this question: Create a program that uses a derived class based

ID: 2246734 • Letter: I

Question

I need help with this question:

Create a program that uses a derived class based on the list class you’ve created in the first program. This program will use a stack data type.
class node {
void *info;
node *next;
public:
node (void *v) {info = v; next = 0; }
void put_next (node *n) {next = n;}
node *get_next ( ) {return next;}
void *get_info ( ) {return info;}
};
class list {
node *head;
int node_num;
public:
list ( ) { node_num = 0; head = 0;}

Here is the code I have for the first question it is referring to:

#include //allows input/output

using namespace std; //using standard namespace library

class linklist //create class linklist
{
private: //private members
   struct node //create struct node
   {
       int data; //declare data as integer
       node *link; //create node variable for link pointer
   }*p; //end struct, first node p

public: //public members
   linklist(); //constructor
   void append(int num); //void function append with variable num as int
   void add_as_first(int num); //void function add as first in list with variable num as int
   void addafter(int c, int num); //void function add after variable c (int) with variable num as int
   void del(int num); //void function delete with variable num as int
   void display(); //void function to display
   int count(); //void function to count
   ~linklist(); //destructor
}; //end class

linklist::linklist() //further constructor
{
p = NULL; //p initially null
}

void linklist::append(int num) //void function append
{
   node *q, *t; //points to nodes q and t in list
   if (p == NULL) //if p is null...
   {
       p = new node; //p is new node
       p->data = num; //assigned num to new node
       p->link = NULL; //there is no node to link to yet
   }
   else //else...
   {
       q = p; //q is assigned p
       while (q->link != NULL) //while q is linked and does not = null
           q = q->link; //q will assess the link
       t = new node; //new node named t
       t->data = num; //new node assigned num
       t->link = NULL; //t is not linked to another node...
       q->link = t; //q is now linked to t
   }
} //end append function

void linklist::add_as_first(int num) //void function add as first
{
   node *q; //node pointing to q
   q = new node; //q is new node
   q->data = num; //assigning num to new node
   q->link = p; //new node linked to p
   p = q; //p assigned q
} //end add as first

void linklist::addafter(int c, int num) //void function add after
{
   node *q, *t; //pointing to nodes q and t
   int i; //declaring i as int for counting
   for (i = 0, q = p; i    {
       q = q->link; //q is linked
       if (q == NULL) //if q is not linked and null
       {
           cout << " There are less than " << c << " elements."; //error message return as there aren't enough elements to add new item in list
           return;
       } //end if
   }
   t = new node; //t is a new node
   t->data = num; //assigning num to the new node
   t->link = q->link; //assigning both links
   q->link = t; //linked to new node
}

void linklist::del(int num) //void function delete
{
node *q, *r; //pointing to q and r
q = p; //q is assigned to p

   if (q->data == num) //if node is = to num
   {
       p = q->link; //p is assigned the q link
       delete q; //will now delete q
       return;
   }
   r = q; //r assigned q
   while (q != NULL) //while q is null
   {
       if (q->data == num) //if data assigned to q is num
       {
           r->link = q->link; //assigning both links
           delete q; //delete the q node
           return;
       }
       r = q; //r is assigned q
       q = q->link; //q is now linked
   }
   cout << " Element " << num << " not Found. "; //output
}

void linklist::display() //void function display
{
   node *q; //node pointer to q
   cout << endl; //display
   for (q = p; q != NULL; q = q->link) //for q assigned p, q is not null, q is linked.
       cout << endl << q->data; //will output the data in the q node
}

int linklist::count() //void function for counter
{
   node *q; //node pointer for q
   int c = 0; //initializing the variable c to 0 (the data member it will find)
   for (q = p; q != NULL; q = q->link) //for q assigned p, q is not null, q is linked
       c++; //count the amount assigned to c
   return c;
}

linklist::~linklist() //destructor, will destruct members in the list
{
   node *q;
   if (p == NULL)
       return;
   while (p != NULL)
   {
       q = p->link;
       delete p;
       p = q;
   }
}

int main() //main function to demonstrate functions
{
linklist newlist; //creates new instance of class
cout << "Number of elements = " << newlist.count(); //First will count initial number of elemenents

   newlist.append(10); //adding 10 to list
   newlist.append(13); //adding 13 to list
   newlist.append(33); //adding 33 to list
   newlist.append(53); //adding 53 to list
   newlist.append(64); //adding 64 to list
   newlist.append(70); //adding 70 to list
   newlist.add_as_first(4); //will add 4 at beginning of list
   newlist.add_as_first(2); //will add 2 to beginning of list
   newlist.addafter(3, 352); //will add number after 3rd data member
   newlist.addafter(6, 669); //will add number after 6th data member
   newlist.display(); //displays all items in the list

cout << " Number of elements = " << newlist.count() << " "; //outputs number of elements using count function

   newlist.del(352); //deletes the 352 member
   newlist.del(13); //deletes the 13 member
   newlist.del(123); //deletes the 123 member

   cout << " Number of elements = " << newlist.count() << " " << endl; //outputs new number of elements after deletion of 3

   return 0;
}

Explanation / Answer

class node {
void *info;
node *next;
public:
node (void *v) {info = v; next = 0; }
void put_next (node *n) {next = n;}
node *get_next ( ) {return next;}
void *get_info ( ) {return info;}
};
class list {
node *head;
int node_num;
public:
list ( ) { node_num = 0; head = 0;}