Add code for the bolded area only: File name : 2170_10_5a.cc Purpose : This prog

Question

Add code for the bolded area only:

File name : 2170_10_5a.cc
Purpose   : This program demonstrates the use of dummy head node
            linked lists and insertion of a node.
******************************************************************************/

#include
#include "2170_10_5a.h"
using namespace std;

// Default Constructor for the DummyList class
DummyList::DummyList()
{
    //create the dummy node
    head = new NodeType;
    head->next = NULL;
    head->data = -1.0;
}

// Default Destructor for the DummyList class
DummyList::~DummyList()
{
    NodePtrType q = head;
    while (q != NULL)
    {
        head = head->next;
        q->next = NULL;
        delete q;
        q = head;
    }
}

//This function inserts a node at the beginning of the list
//Add code to insert the node p at the beginning of the list.
// Remember that head is a dummy node and should never be changed.
void DummyList::InsertAtBeginning(float newData)
{
    NodePtrType p;    //pointer to node to contain new data

    //create the node
    p = new NodeType;
    //store the data
    p->data = newData;

(the code should be inserted here)
}

//This function traverses the list and prints it.
//If the dummy head node has been altered, it prints
//and error.
void DummyList::PrintList()
{
    NodePtrType p;

    p = head;

    if (p->data != -1)
    {
        cout << "Illegal head node" << endl;
    }
    else
    {
        p = p->next;

        while (p != NULL)
        {
            cout << p->data << endl;
            p = p->next;
        }
        
        cout << endl;
    }
}

Explanation / Answer

void DummyList::InsertAtBeginning(float newData)
{
    NodePtrType p; //pointer to node to contain new data
p = (struct Node* ) malloc(sizeof (Node)); //create the node with same memory
p->data=newData;

p->next=head;//new node contain the address of node who was previously first node in the list
head->p//now head contain the address of new node (so this node is first node of the list)
}

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.