how to add insert node , delete node and search node?

Codes for doublelinkedlist hearder and implementation

#ifndef DOUBLELINKEDLIST_H

#define DOUBLELINKEDLIST_H

#include

using namespace std;

struct Node

{

double value;

Node *N, *P;

Node(double y)

{

value = y;

N = P = NULL;

}

};

class doubleLinkedList

{

Node *front;

Node *back;

public:

doubleLinkedList()

{

front = NULL; back = NULL;

}

~doubleLinkedList() { destroyList(); }

void appendNodeFront(double x);

void appendNodeBack(double x);

void insertNode(...);

void deleteNode(...);

void searchNode(...);

void dispNodesForward();

void dispNodesReverse();

void destroyList();

};

void doubleLinkedList::appendNodeFront(double x)

{

Node *n = new Node(x);

if (front == NULL)

{

front = n;

back = n;

}

else

{

front->P = n;

n->N = front;

front = n;

}

}

void doubleLinkedList::appendNodeBack(double x)

{

Node *n = new Node(x);

if (back == NULL)

{

front = n;

back = n;

}

else

{

back->N = n;

n->P = back;

back = n;

}

}

void doubleLinkedList::dispNodesForward()

{

Node *temp = front;

cout << " Nodes in forward order:" << endl;

while (temp != NULL)

{

cout << temp->value << " ";

temp = temp->N;

}

}

void doubleLinkedList::dispNodesReverse()

{

Node *temp = back;

cout << " Nodes in reverse order :" << endl;

while (temp != NULL)

{

cout << temp->value << " ";

temp = temp->P;

}

}

void doubleLinkedList::destroyList()

{

Node *T = back;

while (T != NULL)

{

Node *T2 = T;

T = T->P;

delete T2;

}

front = NULL;

back = NULL;

}

void insertNode(..)

{

// Needs to be completed.

}

void deleteNode(..)

{

// Needs to be completed.

}

Void searchNode(..)

{

// Needs to be completed.

}

#endif

Codes for Main Program to test these functions

#include

#include "doubleLinkedList.h"

using namespace std;

int main()

{

doubleLinkedList *list = new doubleLinkedList();

//append nodes to front of the list

for (int i = 1; i < 4; i++)

list->appendNodeFront(i*1.1);

list->dispNodesForward();

list->dispNodesReverse();

//append nodes to back of the list

for (int i = 1; i < 4; i++)

list->appendNodeBack(11.0 - (1.1 * i));

cout << endl << endl;

list->dispNodesForward();

list->dispNodesReverse();

cout << endl << endl;

delete list;

return 0;

}