public void bubblesortDescending()
{
//apply bubble sort priciples to a linked list
for (MyLinkedListNode i = this.first; i != this.last; i = i.getNext())
{
for (MyLinkedListNode j = i.getNext(); j != null; j = j.getNext())
{
if (i.getData() < j.getData())
{
var temp = i.getData();
i.setData(j.getData());
j.setData(temp);
}
}
}
}
//===============================================
//methods:
public void addFirst(int data)
{
MyLinkedListNode node = new MyLinkedListNode(data);
//check if empty
if (count == 0)
{
first = last = node;
}
else
{
first.setPrevious(node);
node.setNext(first);
first = node;
}
count++;
}
public void addLast(int data)
{
MyLinkedListNode node = new MyLinkedListNode(data);
//check if empty
if (count == 0)
{
first = last = node;
}
else
{
//connect last to node
last.setNext(node);
//connect node back to last
node.setPrevious(last);
//make the node the last one
last = node;
}
count++;
}
public int getData(int index)
{
//make sure that the index is valid
if (index < 0 || index >= count)
{
throw new Exception("index out of bound");
}
//sequence through the linkedlist until you reach the node
//at the given index
//return its data
MyLinkedListNode temp = first;
int i = 0;
while (i < index)
{
temp = temp.getNext();
i++;
}
//temp should be referencing the node at the given index
return(temp.getData());
}
// public int removeLast(){
//
// }
public int[] toArray()
{
//copy the entire list to an array an return it
//create the array
int[] array = new int[count];
//sequence through linkedlist from first node to last
//use a temp to start at the first node
MyLinkedListNode temp = first;
int index = 0;
while (temp != null)
{
//get data from node and copy it to array
array[index] = temp.getData();
//increment index
index++;
//move to next node
temp = temp.getNext();
}
return(array);
}
public void setFirstNode(MyLinkedListNode first)
{
this.first = first;
}
public void setLastNode(MyLinkedListNode last)
{
this.last = last;
}
public MyLinkedList()
{
first = null;
last = null;
count = 0;
}
public void setPrevious(MyLinkedListNode previous)
{
this.previous = previous;
}
public void setNext(MyLinkedListNode next)
{
this.next = next;
}
//constructor
public MyLinkedListNode(int data)
{
this.data = data;
next = null;
previous = null;
}
MyLinkedList ReverseLinkedList(MyLinkedList myLinkedList)
{
MyLinkedListNode left = myLinkedList.getFirst();
MyLinkedListNode right = myLinkedList.getLast();
MyLinkedListNode tempNode = null;
//Shuffle the right neighbours of left node to point to right.
left.getNext().setPrevious(right);
//Shuffle the left of neighbours of right node to point to left.
right.getPrevious().setNext(left);
// make sure that the old left neighbor of right node is now the recent left neighbour of left node
// and the old left neighbour of left node is now the recent left neighbor of right node
tempNode = left.getPrevious();
left.setPrevious(right.getPrevious());
right.setPrevious(tempNode);
// make sure that the old right neighbor of right node is now the recent right neighbour of left node
// and the old right neighbour of left node is now the recent right neighbor of right node
tempNode = left.getNext();
left.setNext(right.getNext());
right.setNext(tempNode);
//Arrange the first and last node as they are at the edge
myLinkedList.setFirstNode(right);
myLinkedList.setLastNode(left);
//Get the first and last after reversing the left and right edge nodes.
left = myLinkedList.getFirst();
right = myLinkedList.getLast();
//This is for the remaining inner nodes.
for (int i = 1; i < myLinkedList.getCount() / 2; i++)
{
left = left.getNext();
if (left == right) //left and right have joined for even length of linked list.
{
break;
}
right = right.getPrevious();
if (left == right)//left and right have joined for odd length of linked list.
{
break;
}
//Shuffle the refences of neighbours of left to point to right.
if (left.getNext() == right) // left and right about to join
{
left.getPrevious().setNext(right);
right.getNext().setPrevious(left);
left.setNext(right.getNext());
right.setPrevious(left.getPrevious());
left.setPrevious(right);
right.setNext(left);
break;
}
left.getNext().setPrevious(right);
left.getPrevious().setNext(right);
//Shuffle the refences of neighbours of right to point to left.
right.getNext().setPrevious(left);
right.getPrevious().setNext(left);
// make sure that the old left neighbor of right node is now the recent left neighbour of left node
// and the old left neighbour of left node is now the recent left neighbor of right node
tempNode = left.getPrevious();
left.setPrevious(right.getPrevious());
right.setPrevious(tempNode);
// make sure that the old right neighbor of right node is now the recent right neighbour of left node
// and the old right neighbour of left node is now the recent right neighbor of right node
tempNode = left.getNext();
left.setNext(right.getNext());
right.setNext(tempNode);
tempNode = left;
left = right;
right = tempNode;
}
return(myLinkedList);
}
