// Function to insert node in linked list = > time complexity O (n)
public void Insert(int index, int value)
{
// 1. Check if index is 0, that means we want to make this new node as new head
if (index == 1)
{
PrePend(value);
}
else
{
// 2. Loop through the list till index position for insert
DoubleLinkNode temp = this.head;
int counter = 1;
while (temp != null)
{
if (counter < index)
{
temp = temp.NEXT;
counter++;
}
else
{
// position found
this.newNode = new DoubleLinkNode(value);
DoubleLinkNode pred = temp.PREV;
temp.PREV = this.newNode;
this.newNode.PREV = pred;
pred.NEXT = this.newNode;
this.newNode.NEXT = temp;
this.nodeLength++;
break;
}
}
}
}
// Function to prepend node to linked list : in start => time complexity O(1)
public void PrePend(int value)
{
// 1. Create the default Node structure for new value
this.newNode = new DoubleLinkNode(value);
// 2. Set & move head to new node
this.newNode.NEXT = this.head;
this.head.PREV = this.newNode;
this.head = this.newNode;
nodeLength++;
}
// Function to append node to linked list : in end => time complexity O(1)
public void AppendNode(int value)
{
// 1. Create the default Node structure for new value
this.newNode = new DoubleLinkNode(value);
// 2. Set & move tail to new node
this.tail.NEXT = this.newNode;
this.newNode.PREV = this.tail;
this.tail = this.newNode;
nodeLength++;
}
// constructor function
public DoublyLinkedList(int value)
{
// create default node structure for value
this.newNode = new DoubleLinkNode(value);
// point head to this first node
this.head = this.newNode;
// point tail to this first node head
this.tail = this.newNode;
// Set length to 1 as its first node
nodeLength = 1;
}
// Display function for Linked list Data => time complexity O(n)
public void PrintAllNodes()
{
// set the variable on the linked list head
DoubleLinkNode currentNode = this.head;
// Now loop through all the elements till end of linked list
while (currentNode != null)
{
Console.Write("Node Value : {0} ---> ", currentNode.NODEVALUE);
currentNode = currentNode.NEXT;
// Console.ReadLine();
}
Console.WriteLine("Total nodes :{0}", this.nodeLength);
}
public void Remove(int value)
{
DoubleLinkNode temp = this.head;
DoubleLinkNode pred;
DoubleLinkNode succ;
if (this.head.NODEVALUE == value)
{
succ = this.head.NEXT;
succ.PREV = null;
this.head = succ;
this.nodeLength--;
}
else
{
if (this.tail.NODEVALUE == value)
{
pred = this.tail.PREV;
pred.NEXT = null;
this.tail = pred;
this.nodeLength--;
}
else
{
while (temp != null)
{
if (temp.NODEVALUE == value)
{
pred = temp.PREV;
succ = temp.NEXT;
pred.NEXT = succ;
succ.PREV = pred;
this.nodeLength--;
break;
}
else
{
pred = temp;
temp = temp.NEXT;
// succ = temp.NEXT;
}
}
}
}
}
