In this playlist https://youtube.com/playlist?list=PLT...​ I'll illustrate algorithms and data structures course, and implement the data structures using java programming language. the playlist language is arabic. The Topics: -------------------- 1- Arrays 2- Linear and Binary search 3- Linked List 4- Recursion 5- Algorithm analysis 6- Stack 7- Queue 8- Binary search tree 9- Selection sort 10- Insertion sort 11- Bubble sort 12- merge sort 13- Quick sort 14- Graphs 15- Hash table 16- Binary Heaps Reference : Object-Oriented Data Structures Using Java - Third Edition by NELL DALE, DANEIEL T.JOYCE and CHIP WEIMS Slides is owned by College of Computing & Information Technology King Abdulaziz University, So thanks alot for these great materials

1. College of Computing & Information Technology
King Abdulaziz University
CPCS-204 – Data Structures I
Link Lists Gone Wild:
Circular and Doubly
Linked Lists

2. Linked Lists Gone Wild: Doubly-Linked Lists page 2
© Dr. Jonathan (Yahya) Cazalas
Double-Linked Lists
 Limitations of a singly-linked list include:
 Insertion at the front is O(1)
 insertion at other positions is O(n)
 Insertion is convenient only after a referenced node
 Removing a node requires a reference to the previous
node
 We can traverse the list only in the forward direction
 We can overcome these limitations:
 Add a reference in each node to the previous node,
creating a double-linked list

3. Linked Lists Gone Wild: Doubly-Linked Lists page 3
© Dr. Jonathan (Yahya) Cazalas
Double-Linked Lists (cont.)

4. Linked Lists Gone Wild: Doubly-Linked Lists page 4
© Dr. Jonathan (Yahya) Cazalas
Linked Lists
 Here’s a doubly linked list node class:
public class DLLnode {
public int data;
public dll_node next;
public dll_node prev;
// Constructor 1
public DLLnode(int i) {
this(i, null, null);
}
// Constructor 2
public DLLnode(int i, dll_node n, dll_node p) {
data = i;
next = n;
prev = p;
}
}
Each ll_node object has
at least 3 fields:
(1) data field, which
stores information
(2) next field, which is
used to link the nodes
together
(3) previous, which links
to previous node

5. Linked Lists Gone Wild: Doubly-Linked Lists page 5
© Dr. Jonathan (Yahya) Cazalas
Inserting into a Double-Linked
List
next =
= prev
data = "Harry"
DLLnode
next = null
= prev
data = "Sam"
DLLnode
next =
= prev
data = "Sharon"
DLLnode
DLLnode newNode= new DLLnode("Sharon");
newNode.next = helpPtr;
newNode.prev = helpPtr.prev;
helpPtr.prev.next = newNode;
helpPtr.prev = newNode;
from predecessor
to
predecessor
helpPtr
newNode

6. Linked Lists Gone Wild: Doubly-Linked Lists page 6
© Dr. Jonathan (Yahya) Cazalas
Removing from a Double-Linked
List
next =
= prev
data = "Bob"
Node
next =
= prev
data = "Harry"
Node
next =
= prev
data = "Sharon"
Node
helpPtr
helpPtr.prev.next = helpPtr.next;
helpPtr.next.prev = helpPtr.prev;

7. Linked Lists Gone Wild: Doubly-Linked Lists page 7
© Dr. Jonathan (Yahya) Cazalas
A Double-Linked List Class
So far we have worked only
with internal nodes
As with the single-linked class,
it is best to access the internal
nodes with a double-linked list
object
A double-linked list object has data fields:
 head (a reference to the first list Node)
 tail (a reference to the last list Node)
Insertion at either end is O(1)
insertion elsewhere is still O(n)

8. Linked Lists Gone Wild: Doubly-Linked Lists page 8
© Dr. Jonathan (Yahya) Cazalas
Circular Lists
 Circular double-linked list:
 Link last node to the first node, and
 Link first node to the last node
 We can also build singly-linked circular lists:
 Traverse in forward direction only
 Advantages:
 Continue to traverse even after passing the first or last node
 Visit all elements from any starting point
 Never fall off the end of a list
 Disadvantage: Code must avoid an infinite loop!

9. Linked Lists Gone Wild: Doubly-Linked Lists page 9
© Dr. Jonathan (Yahya) Cazalas
Circular Lists (cont.)

10. Linked Lists Gone Wild: Doubly-Linked Lists page 10
© Dr. Jonathan (Yahya) Cazalas
Linked Lists Gone Wild
ISN’T
THAT
GREAT ( )!
That we are finished
with Linked Lists!

11. Linked Lists Gone Wild: Doubly-Linked Lists page 11
© Dr. Jonathan (Yahya) Cazalas
Daily Demotivator

12. College of Computing & Information Technology
King Abdulaziz University
CPCS-204 – Data Structures I
Link Lists Gone Wild:
Circular and Doubly
Linked Lists