Data structures

1. Data Structures

2. Agenda
 Introduction
 Arrays
 Linked list
 Single linked list
 Double linked list
 Stack
 Queue

3. Introduction
Data Structure:
a way to store and organize data in the structured
manner.
Computer's memory is divided into small parts, we
use different data structures to store data in those
small blocks.
Example: Arrays, Linked list, Trees ..........

4. Arrays
 Array is basic data structure in which we store data
in continues memory locations.
 Array is variable which holds mulitiple elements of
same type.
 Arrays reduce the redendency
 Generic form of arrays:
data type array_name[size];
 Data type: what type of data(int, float, char...)
 Size: number elements you want to store

5. Arrays
 Every element will have index value
 If you want to access any element we must use index
value of the element.
 Disadavantages:
 Capable of holding only one type of elements.
 Insertion and deletion is very difficult
 Waste of memory is very high

6. Linked list
 Linked list: collection of nodes which or connected
together
 Node: is just like variable but it holds data and
address of the next node or null.
 Adavantages:
 Memory efficincy is very high
 Insertion and deletion is very easy and fast.

7. Linked list
 When linked list is useful:
 Do not know the number of data elements
 Your list need to be sorted quickly
 Disadvantages:
 Traversal is very slow
 If you want to access 10th element in the list you
need to cross 9 elements (arrays are very fast
because of index)
 You can move only in one direction in single
linked list
 If one link is corrupted remain data will be lost.

8. Example program on linked list

9. Double Linked list
 In single linked we can move only in one direction
 Double linked list allow us to move in direction.
 Double linked is also collection of nodes, but here
node is contains more than 2 fields.
 Node: one field holds data, second field holds
address of next node or null and third field holds
address of previous node or null.

10. Double linked list
 Disadvantages:
 Need extra space for holding references.
 Still it is very slow to travel across the list.
 Circular linked list:
 If the head of linked list is connected to tail that list
is called circular linked list.
 Application of linked list:
 Stacks and Queues.

11. Example program

12. Stack
 Stack
 New nodes can be added and removed only at the
top
 Similar to a pile of dishes
 Last-in, first-out (LIFO)
 Bottom of stack indicated by
a link member to NULL
 Constrained version
of a linked list

13. Operations on Stack
 push
 Adds a new node to the top of the stack
 pop
 Removes a node from the top
 Stores the popped value
 Returns true if pop was successful

14. Queue
 Queue
 Similar to a supermarket checkout line
 First-in, first-out (FIFO)
 Nodes are removed only from the head
 Nodes are inserted only at the tail

15. Operations on Queue
 Insert and remove operations
 Enqueue (insert) and dequeue (remove)
 Disadvantages:
What happens if you're 10th in line at the supermarket and it takes 5 minutes to
process each person ahead of you?
You wait 45 minutes.

16. References
 http://ccodings.blogspot.com
 http://afizafiz.blogspot.com/2010/10/linked-list-in-c-
programming.html