Introduction - Data Structure

Data Structure

è      Data in computer system organized in many different ways. The logical and mathematical model of a particular organization of data is called data structure.

è      Choice of a particular data model depends on two consideration :

1. It must be rich enough in structure to mirror the actual relationship of the data in the real world.
2. The structure should be simple enough that one can effectively process the data when necessary.

è        A data values permanently stored on a file or temporary stored in a memory which represents a data. Normally , the different data values are related to each other. These data  values must be organized  from and make use of relationship in programs.

è        To access and process structured  data, the programs have to follow certain rule. Therefore the  are represented as:

Data Structure= Organized  Data+Allowed Operation 

Data structure mainly divides into two types:

1.     Primitive Data structure

2.     Non- Primitive Data structure

The hierarchical representation of data structure is shown in following figure:

Primitive Data Structure :

1.  Integer

          Integer is numbers with a range of values supported by a computer. Integer requires 2 bytes in computer memory. A range of integer value is -32768 to +32767.

          In the c language there are 3 classes of integer storage called short integr, long integer and integer. Short integer can store can store half value than regular integer. %d is used as a format specifier of integer.

2.  Float

          The float data type is used to store floating point numbers. The range of float is 1.7e-38 to 1.7e+38 float occupies 4 bytes in memory. %f is used as a format specifier in float. Float data type provides 6 digits of accuracy.

3. Double

          A double data type is also used to store floating point values, but it provides 14 digits of accuracy. Range of double is 1.7e-308 to 1.7e+308. this data type requires 8 bytes in memory.

          %lf is used as a format specifier in double data type.

4. Character

A single character can be defined as a character data type. Character is used 1 byte for storage %c is used as a format specifier in character.

Non-Primitive data structure

The data types which is derived from the primitive data types is called non primitive data structure. It is also known as composite types. It is classified in to two types:

1. Linear data structure

Array , Stack ,Queue , Linked list, File and Structure.

2. Non Linear data structure

Tree, Graph.

    

Linear Data structure

1. Array

An array is a collection of similar data elements that stores in sequential memory locations.

2. Linked list

A linked list can be defined as collection of nodes. A node has two fields information and address of the next node. Nodes are nothing of dynamic structure values connected to each other by means of pointes.

3. Stack

A stack is a data structure where information is stored in Last in first out(LIFO) method. All insertion and deletion s of data can take place at the end of , called TOS Top of the stack.

4. Queue

A queue is the data structure where information is stored in First in First out (FIFO) method. In this structure deletion take place at front end ,  and insertion take place at rear end.

Non – Linear data structure

1.    Tree

The tree data structure which reflects the hierarchical relationship between data various data elements. There are different type of tree called binary tree, Expression tree, Search tree, B- tree, AVL tree etc. It performs different operations like insertion,  deletion,  searching of data with different traversing method.

2.    Graph

This data structure contains relationship between pairs of elements. It may or may not contain hierarchical relationship. There are different types of graphs depending on the nature of the representation of that graph.

Posted By : Ruchita Pandya