9/18/24, 2:17 Data structure full
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DATA STRUCTURES
UNIT I
Data structure is a particular way of organizing data in a computer so that it
can be used effectively.
Data Structures are widely used in almost every aspect of Computer Science i.e.
Operating System, Compiler Design, Artificial intelligence, Graphics and many
more.
Data Structures are the main part of many computer science algorithms as they
enable the programmers to handle the data in an efficient way. It plays a vital
role in enhancing the performance of a software or a program as the main
function of the software is to store and retrieve the user's data as fast as possible
Example of data structures
1. Arrays
An array is a structure of fixed-size, which can hold items of the same
data type. It can be an array of integers, an array of floating-point
numbers, an array of strings or even an array of arrays (such as 2-
dimensional arrays). Arrays are indexed, meaning that random access is
possible.
2. Linked Lists
A linked list is a sequential structure that consists of a sequence of
items in linear order which are linked to each other. Hence, you have to
access data sequentially and random access is not possible.
about:bl 1/
,9/18/24, 2:17 Data structure full
PM notes
3. Stacks
A stack is a LIFO (Last In First Out 4 the element placed at last can be
accessed at first) structure which can be commonly found in many
programming languages. This structure is named as 5stack” because it
resembles a real-world stack 4 a stack of plates.
4. Queues
A queue is a FIFO (First In First Out 4 the element placed at first can be
accessed at first) structure which can be commonly found in many
programming languages. This structure is named as 5queue” because it
resembles a real-world queue 4 people waiting in a queue.
5. Trees
A tree is a hierarchical structure where data is organized hierarchically
and are linked together. This structure is different than a linked list
whereas, in a linked list, items are linked in a linear order.
6. Graphs
A graph consists of a finite set of vertices or nodes and a set
of edges connecting these vertices.
Elementary Data Organization
Data: Data can be defined as an elementary value, for example, student's name
and his roll number are the data about the student.
Group Items: Data items which have subordinate data items are called Group
item, for example, name of a student can have first name and the last name.
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,9/18/24, 2:17 Data structure full
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Record: Record can be defined as the collection of various data items, for
example, if we talk about the student entity, then his name, address, course and
marks can be grouped together to form the record for the student.
File: A File is a collection of various records of one type of entity, for example,
if there are 60 employees in a Bank, then there will be 60 records in the related
file where each record contains the data about each employee.
Entity: An entity is a person, place, thing, event or concept about which
information recorded.
What is the difference between a data structure and a data type?
Data type Data structure
A data type describes pieces of data A data structure is a way of describing
that all share a common property. a certain way to organize pieces of
data so that operations and algorithms
can be more easily applied.
For example an integer data type
For example tree type data structures
describes every integer that the
often allow for efficient searching
computer can handle.
algorithms.
Values can directly be assigned to the
The data is assigned to the data
data type variables.
structure object using some set of
algorithms and operations like push,
pop and so on.
No problem of time complexity Time complexity comes into play
when working with data structures.
about:bl 3/
, 9/18/24, 2:17 Data structure full
PM notes
Examples: int, float, double Examples: stacks, queues, tree
Categories of data structure
Data structures can be classified as follows
Primitive Data Structures
These are the structures which are supported at the machine level, they can be
used to make non-primitive data structures. These are integral and are pure in
form. They have predefined behavior and specifications.
Examples: Integer, float, character etc
about:bl 4/
PM notes
DATA STRUCTURES
UNIT I
Data structure is a particular way of organizing data in a computer so that it
can be used effectively.
Data Structures are widely used in almost every aspect of Computer Science i.e.
Operating System, Compiler Design, Artificial intelligence, Graphics and many
more.
Data Structures are the main part of many computer science algorithms as they
enable the programmers to handle the data in an efficient way. It plays a vital
role in enhancing the performance of a software or a program as the main
function of the software is to store and retrieve the user's data as fast as possible
Example of data structures
1. Arrays
An array is a structure of fixed-size, which can hold items of the same
data type. It can be an array of integers, an array of floating-point
numbers, an array of strings or even an array of arrays (such as 2-
dimensional arrays). Arrays are indexed, meaning that random access is
possible.
2. Linked Lists
A linked list is a sequential structure that consists of a sequence of
items in linear order which are linked to each other. Hence, you have to
access data sequentially and random access is not possible.
about:bl 1/
,9/18/24, 2:17 Data structure full
PM notes
3. Stacks
A stack is a LIFO (Last In First Out 4 the element placed at last can be
accessed at first) structure which can be commonly found in many
programming languages. This structure is named as 5stack” because it
resembles a real-world stack 4 a stack of plates.
4. Queues
A queue is a FIFO (First In First Out 4 the element placed at first can be
accessed at first) structure which can be commonly found in many
programming languages. This structure is named as 5queue” because it
resembles a real-world queue 4 people waiting in a queue.
5. Trees
A tree is a hierarchical structure where data is organized hierarchically
and are linked together. This structure is different than a linked list
whereas, in a linked list, items are linked in a linear order.
6. Graphs
A graph consists of a finite set of vertices or nodes and a set
of edges connecting these vertices.
Elementary Data Organization
Data: Data can be defined as an elementary value, for example, student's name
and his roll number are the data about the student.
Group Items: Data items which have subordinate data items are called Group
item, for example, name of a student can have first name and the last name.
about:bl 2/
,9/18/24, 2:17 Data structure full
PM notes
Record: Record can be defined as the collection of various data items, for
example, if we talk about the student entity, then his name, address, course and
marks can be grouped together to form the record for the student.
File: A File is a collection of various records of one type of entity, for example,
if there are 60 employees in a Bank, then there will be 60 records in the related
file where each record contains the data about each employee.
Entity: An entity is a person, place, thing, event or concept about which
information recorded.
What is the difference between a data structure and a data type?
Data type Data structure
A data type describes pieces of data A data structure is a way of describing
that all share a common property. a certain way to organize pieces of
data so that operations and algorithms
can be more easily applied.
For example an integer data type
For example tree type data structures
describes every integer that the
often allow for efficient searching
computer can handle.
algorithms.
Values can directly be assigned to the
The data is assigned to the data
data type variables.
structure object using some set of
algorithms and operations like push,
pop and so on.
No problem of time complexity Time complexity comes into play
when working with data structures.
about:bl 3/
, 9/18/24, 2:17 Data structure full
PM notes
Examples: int, float, double Examples: stacks, queues, tree
Categories of data structure
Data structures can be classified as follows
Primitive Data Structures
These are the structures which are supported at the machine level, they can be
used to make non-primitive data structures. These are integral and are pure in
form. They have predefined behavior and specifications.
Examples: Integer, float, character etc
about:bl 4/
