Wel Come to Data Structure class

Junaid khanVisiting Lecturer University of Peshawar

DATA STRUCTURE AND ITS TYPES

Data StructureIt is a logical way of storing data and it also define mechanism of

retrieve data.

What are Data Structures? Data may be organized in many different ways. A Data Structure is an arrangement of data in

a computer’s memory or on a disk. The logical or mathematical model of a

particular organization of a data is called Data Structures.

The choice of a data model depends on two consideration:

1) It must be rich enough in structure to mirror the actual relationships of the data in the real world.

2) The structure should be simple enough that one can effectively process the data when necessary.

Types of Data Structure

DATA STRUCTURE

NON LINEARLINEAR

Data Structure Operation

The data appearing in data structures are processed by means of operations. The following are operations are major operations:

a) Traversing: Accessing each record exactly once so that certain items in the record may be processed.

b) Searching: Finding the location of the record with a given key value, or finding the locations of all records which satisfy one or more conditions.

c) Inserting: Adding a new record to the structure.d) Deleting: Removing a record from the structure.

Following two are special operations:

a) Sorting: Arranging the records in some logical order.

b) Merging: Combining the records in two different sorted files into a single sorted file.

What are Algorithms?An algorithm is a well-defined list of steps for solving a particular problem.Algorithms manipulate the data present in data structures in various ways, such as searching for a particular data item and sorting the data.Flowcharts are pictorial representations of the algorithms.Properties/ characteristics of the algorithm:

a) Finiteness: Total number of steps used in an algorithm should be finite.

b) Definiteness: Each step of algorithm must be clear and unambiguous.

c) Effectiveness: Every step must be basic and essential.

d) Input/output: The algorithm must accept zero or more input and must produce at least on output.

Linear Data Structure1.Array2.Stack3.Queue4.Linked List

1.ArrayAn array is a collection of homogeneous type of data elements.An array is consisting of a collection of elements .

Operation Performed On Array1.Traversing2.Search3.Insertion4.Deletion5.Sorting6.Merging

Representation of array in memory1

2

3

4

5

Array Representation

2.StackA Stack is a list of elements in which an element may be inserted or deleted at one end which is known as TOP of the stack.

Operation Performed on Stack Push: add an element in stack Pop: remove an element in stack

Representation of Stack

EEE TOP

DDD

CCC

BBB

AAA

Stack Representation

3.QueueA queue is a linear list of element in which insertion can be done at one end which is known as front and deletion can be done which is known as rear.

Operation Performed On QueueInsertion : add a new element in queueDeletion: Removing an element in queue

Representation of Queue

55 65 75

Queue Representation

4.Linked ListA Linked list is a linear collection of data elements .It has two part one is info and other is link part.info part gives information and link part is address of next node

Operation Performed on Linked List1.Traversing2.Searching3.Insertion4.Deletion

Linked Representation

2.Non Linear1.Tree2.Graph

1.TreeIn computer science, a tree is a widely-used data structure that emulates a hierarchical tree structure with a set of linked nodes.

Operation On Tree1.Insertion2.Deletion3.Searching

Tree Representation

2.GraphA graph data structure may also associate to each edge some edge value, such as a symbolic label or a numeric attribute (cost, capacity, length, etc.).

Operation Performed Graph1.Searching2.Insertion3.Deletion

Graph Representation

THANKS