This document defines and compares common data structures like lists, stacks, and queues. It describes their abstract definitions, common operations, and different implementation methods. Lists can be implemented with arrays or linked nodes and support insertion, deletion, and retrieval of elements. Stacks and queues follow last-in first-out and first-in first-out rules respectively.

1. LIST,STACK,QUEUE

2. What is Algorithm?
An algorithm is a set of rules for carrying out calculation
either by hand or on a machine.
Data structures
Methods of organizing data
Program = algorithms + data structures
2 kinds of algorithm efficiencies
 Space efficiency /space complexity
 How much extra space the algorithm needs
 Time efficiency / time complexity
 How much time does it take to run the algorithm?
 How fast the algorithm runs?

3. SET OF FUNCTIONS TO REPRESENT GROWTH
RATES IN INCREASING ORDER OF MAGNITUDES:
Function Name
 c constant
 lg n logarithmic
 n linear
 n lgn n lgn (between
linear and quadratic)
 n2 quadratic
 n3 cubic
 2n exponential
 n! factorial

4. ABSTRACT DATA TYPES (ADT)
 Definition of data
 Definition of operations
 Encapsulation of data & operation

5. LIST ADT
 General Linear list
 Operations possible –Insertion ,Deletion & Retrieval of
an element
 Implementations
 Array
 Linked list

6. ARRAY IMPLEMENTATION
A0, A1, A2, ..., AN-1
A0 A1 A2 An-1
Operation: insertion
A0 A1 A2 An-1
A0 A’ A1 A2 An-1 An
Operation: deletion
A0 AA11 A2 An-1
A0 A2 An-1

7. LINKED LIST
 A linked list is a collection of nodes that together form a
linear ordering. Each node is a compound object that
stores an element and a reference, called next, to
another node.
Structure of a node
A0 A1 A2 A3
first
Data Link

8. LINKED LIST TYPES
1.Single linked lists :
Each node contains two links – to the previous and to
the next node
2.Double linked lists :
Each node contains a link only to the next node
3.Circular lists:
The tail is linked to the head.

9. The List operations:
Insertion operation:
Deletion operation:
first
20 10 30 11
link
data
0
80

10. Traversal:
public int countNodes()
{
int count = 0;
Element e = head;
while(e != null)
{
count++;
e = e.next;
}
return count;
}
A method that computes the number of elements in any
list

11. Retrieval operation:
public int countElement()
{
int count = 0,num;
Element e = head;
while(e != null)
{
if(e.data==num)
count++;
e = e.next;
}
return count;
}
A method that computes the number of occurance an
element in any list

12. DOUBLY LINKED LIST
 An ordered sequence of nodes in which each node
has two pointers: left and right.

13. INSERTION OPERATION:

14. CIRCULAR LINKED LIST

15. CIRCULAR DOUBLY LINKED LIST
 Add a head node at the left and/or right ends
 In a non-empty circular doubly linked list:
 LeftEnd->left is a pointer to the right-most node
(i.e., it equals RightEnd)
 RightEnd->right is a pointer to the left-most node
(i.e., it equals LeftEnd)

16. STACK ADT
 A stack is a restricted linear list in which all additions and
deletions are made at one end, the top
 This reversing attribute is why stacks are known as last in,
first out (LIFO) data structures
The stack operations
Push operation:
The push operation inserts an item at the top of the stack

17. Pop operation:
The pop operation deletes the item at the top of the stack
Empty operation:
The empty operation checks the status of the stack. This
operation returns true if the stack is empty and false if the
stack is not empty.

18. STACK IMPLEMENTATIONS

19. QUEUE ADT
 A queue is a linear list in which data can only be
inserted at one end, called the rear, and deleted from
the other end, called the front. In other words, a queue
is a first in, first out (FIFO) structure.
Operations on queues:
 Enqueue operation:
The enqueue operation inserts an item at the rear of the
queue

20. Dequeue operation:
The dequeue operation deletes the item at the front of the queue

21. QUEUE IMPLMENTATIONS