Data Structures
Introduction to Data Structures
Short Answers
1. Define Data Structures
Data Structures is defined as the
way of organizing all data items that consider not only the elements stored but
also stores the relationship between the elements.
2. Define primary data structures
Primary data structures are the
basic data structures that directly operate upon the machine instructions. All
the basic constants (integers, floating-point numbers, character constants,
string constants) and pointers are considered as primary data structures.
3. Define static data structures
A data structure formed when the
number of data items are known in advance is referred as static data structure
or fixed size data structure.
4. List some of the static data structures in
C
Some of the static
data structures in C are arrays, pointers, structures etc.
5. Define dynamic data structures
A data structure
formed when the number of data items are not known in advance is known as
dynamic data structure or variable size data structure.
6. List some of the dynamic data structures in
C
Some of the dynamic
data structures in C are linked lists, stacks, queues, trees etc.
7.Why you need a data structure?
A data structure helps
you to understand the relationship of one data element with the other and
organize it within the memory. Sometimes the organization might be simple and
can be very clearly visioned. Eg) List of names of months in a year –Linear Data
Structure, List of historical places in the world- Non-Linear Data Structure. A
data structure helps you to analyze the data, store it and organize it in a
logical and mathematical manner.
8. Difference between Abstract Data Type, Data
Type and Data Structure
• An Abstract data
type is the specification of the data type which specifies the logical and
mathematical model of the data type.
• A data type is the
implementation of an abstract data type.
• Data structure
refers to the collection of computer variables that are connected in some
specific manner. i.e) Data type has its root in the abstract data type and a
data structure comprises a set
of computer variables of same or different data types
9. Define data type and what are the types of
data type?
Data type refers to
the kinds of data that variables may hold in the programming language. Eg) int,
float, char, double – C
The following are the
types of data type:
• Built in data type-
int, float, char, double which are defined by programming language itself
• User defined data type- Using the set of built in data types user can define
their own data type
Eg)
typedef struct student
{
int roll;
char name;
} S;
S s1 ;
Where S is a tag for
user defined data type which defines the structure student and s1 is a variable
of data type S.
10. Define an Abstract Data Type (ADT)
An abstract data type
is a set of operations. ADTs are mathematical abstractions; nowhere in an ADT’s
definition is there any mention of how the set of operations is implemented.
Objects such as lists, sets and graphs, along with their operations can be
viewed as abstract data types.
11. What are the advantages of modularity?
• It is much easier to
debug small routines than large routines
• It is easier for
several people to work on a modular program simultaneously
• A well-written
modular program places certain dependencies in only one routine, making changes
easier
12. State the difference between
primitive and non-primitive data types
Primitive data types
are the fundamental data types. Eg) int, float, double, charNon-primitive data
types are user defined data types. Eg) Structure, Union and enumerated data
types
13. State the difference between
persistent and ephemeral data structure
Persistent data
structures are the data structures which retain their previous state and
modifications can be done by performing certain operations on it. Eg) Stack
Ephemeral data structures are the data structures which cannot retain its
previous state. Eg) Queues
14. What are the objectives of studying
data structures?
• To identify and
create useful mathematical entities and operations to determine what classes of
problems can be solved using these entities and operations
• To determine the representation of these abstract entities and to implement
the abstract operations on these concrete representation
15. Define linear data structures
Linear data structures are data
structures having a linear relationship between its adjacent elements. Example
Linked lists
16. Define non-linear data structures
Non-linear data structures are data
structures that don’t have a linear relationship between its adjacent elements
but have a hierarchical relationship between the elements. Example Trees and
Graphs
17. Define Linked Lists
Linked list consists of a series of
structures, which are not necessarily adjacent in memory. Each structure
contains the element and a pointer to a structure containing its successor. We
call this the Pointer. The last cell’s pointer points to NULL.
18. State the different types of linked lists
The different types of
linked list include singly linked list, doubly linked list and circular linked
list.
19.
List the basic operations carried out in a linked list
The basic operations carried out in a linked list include:
1.Creation of a list
2.Insertion of a node
3.Deletion of a node
4.Modification of a node
5.Traversal of the list
20. List out the advantages of using a
linked list
Ø It is not necessary to
specify the number of elements in a linked list during its declaration
Ø Linked list can grow and shrink in size
depending upon the insertion and deletion that occurs in the list
Ø Insertions and deletions at any place in a
list can be handled easily and efficiently
Ø A linked list does not waste any memory space
21. List out the
disadvantages of using a linked list
Ø Searching a particular
element in a list is difficult and time consuming
Ø A linked list will use more storage space than
an array to store the same number of elements
22. List out the
applications of a linked list
Some of the
important applications of linked lists are manipulation of polynomials, sparse
matrices, stacks and queues.
23. State the difference between arrays
and linked lists
|
Arrays
|
Linked Lists
|
|
Size
of an array is fixed
|
Size
of a list is variable
|
|
It
is necessary to specify the number of elements during declaration
|
It
is not necessary to specify the number of elements during declaration
|
|
Insertions
and deletions are somewhat difficult
|
Insertions
and deletions are carried out easily
|
|
It
occupies less memory than a linked list for the same number of elements
|
It
occupies more memory
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