25+ Data Structure Interview Questions

25+ Data Structure Interview Questions

Data Structure Interview Questions

1) What is Data Structure? Clarify. 

The information structure is a way that determines how to arrange and control the information. It additionally characterizes the connection between them. A few instances of Data Structures are clusters, Linked List, Stack, Queue, and so on. Information Structures are the focal piece of numerous software engineering calculations as they empower the developers to deal with the information in an effective way

2) Describe the sorts of Data Structures? 

Information Structures are for the most part characterized into two sorts:

Straight Data Structure: An information structure is called direct if the majority of its components are organized in the successive request. In straight information structures, the components are put away in a non-progressive manner where every thing has the successors and ancestors aside from the first and last component.

Non-Linear Data Structure: The Non-straight information structure does not frame a succession for example every thing or component is associated with at least two different things in a non-direct course of action. The information components are not orchestrated in the successive structure.

3) List the zone of utilizations of Data Structure. 

Information structures are connected widely in the accompanying zones of software engineering:

Compiler Design,

Working System,

Database Management System,

Factual investigation bundle,

Numerical Analysis,


Man-made reasoning,


4) What is the distinction between record structure and capacity structure? 

Distinction between record structure and capacity structure:

The principle distinction between record structure and capacity structure depends on memory region that is being gotten to.

Capacity structure: It is the portrayal of the information structure in the PC memory.

Record structure: It is the portrayal of the capacity structure in the assistant memory.

5) List the information structures which are utilized in RDBMS, Network Data Modal, and Hierarchical Data Model. 

RDBMS utilizes Array information structure

System information show utilizes Graph

Hierarchal information demonstrate utilizes Trees

6) Which information structure is utilized to perform recursion? 

Stack information structure is utilized in recursion because of its toward the end in first out nature. Working framework keeps up the stack so as to spare the emphasis factors at each capacity call

7) What is a Stack? 

Stack is an arranged rundown in which, inclusion and erasure can be performed just toward one side that is known as the top. It is a recursive information structure having pointer to its top component. The stack is now and then called as Last-In-First-Out (LIFO) list for example the component which is embedded first in the stack will be erased last from the stack.

8) List the zone of utilizations where stack information structure can be utilized? 

Articulation assessment


Memory Management

Capacity calling and return

9) What are the tasks that can be performed on a stack? 

Push Operations

Pop Operations

Look Operations

10) Write the stack flood condition. 

Flood happens when top = Maxsize - 1

11) What is the contrast among PUSH and POP? 

PUSH and POP activities determine how information is put away and recovered in a stack.

PUSH: PUSH determines that information is being "embedded" into the stack.

POP: POP indicates information recovery. It implies that information is being erased from the stack.

12) Write the means associated with the addition and cancellation of a component in the stack. 


Augmentation the variable top with the goal that it can allude to the following memory designation

Duplicate the thing to the at the cluster file esteem equivalent to the top

Rehash stage 1 and 2 until stack floods


Store the highest component into the an another variable

Decrement the estimation of the top

Return the highest component

13) What is a postfix articulation? 

An articulation in which administrators pursue the operands is known as postfix articulation. The primary advantage of this structure is that there is no compelling reason to gather sub-articulations in brackets or to think about administrator priority.

The articulation "a + b" will be spoken to as "ab+" in postfix documentation.

14)Write the postfix type of the articulation: (A + B) * (C - D) 



15) Which documentations are utilized in Evaluation of Arithmetic Expressions utilizing prefix and postfix frames? 

Clean and Reverse Polish documentations.

16)What is an exhibit? 

Exhibits are characterized as the gathering of comparable sorts of information things put away at adjoining memory areas. It is the least complex information structure in which every datum component can be arbitrarily gotten to by utilizing its file number.

17) How to reference every one of the components in a one-measurement exhibit? 

It very well may be finished by utilizing a filed circle with the end goal that the counter keeps running from 0 to the exhibit estimate short one. As such, you can reference every one of the components in arrangement by utilizing the circle counter as the exhibit subscript.

18) What is a multidimensional cluster? 

The multidimensional cluster can be characterized as the variety of exhibits in which, the information is put away in unthinkable structure comprises of lines and sections. 2D exhibits are made to execute a social database clone information structure. It gives simplicity of holding the main part of information without a moment's delay which can be passed to any number of capacities wherever required.

19) How are the components of a 2D cluster are put away in the memory? 

There are two methods by utilizing which, the components of a 2D cluster can be put away in the memory.

Line Major Order: In line real requesting, every one of the columns of the 2D cluster are put away into the memory adjoiningly. In the first place, the first column of the exhibit is put away into the memory totally, at that point the second line of the cluster is put away into the memory totally, etc till the last line.

Section Major Order: In segment real requesting, every one of the segments of the 2D cluster are put away into the memory adjoiningly. to begin with, the first segment of the exhibit is put away into the memory totally, at that point the second line of the cluster is put away into the memory totally, etc till the last segment of the cluster.

20) Calculate the location of an arbitrary component present in a 2D cluster, given base location as BA. 

Line Major Order: If cluster is pronounced as a[m][n] where m is the quantity of lines while n is the quantity of segments, at that point address of a component a[i][j] of the exhibit put away in column real request is determined as,

Address(a[i][j]) = B. A. + (I * n + j) * estimate

Section Major Order: If cluster is announced as a[m][n] where m is the quantity of lines while n is the quantity of segments, at that point address of a component a[i][j] of the exhibit put away in segment significant request is determined as

Address(a[i][j]) = ((j*m)+i)*Size + BA.

21) Define Linked List Data structure. 

Connected List is the accumulation of haphazardly put away information objects called hubs. In Linked List, every hub is connected to its contiguous hub through a pointer. A hub contains two fields, for example Information Field and Link Field.

connected rundown

22) Are connected records thought about direct or non-straight information structures? 

A connected rundown is viewed as both straight and non-direct information structure contingent on the circumstance.

Based on information stockpiling, it is considered as a non-direct information structure.

Based on the entrance system, it is considered as a direct information structure.

23) What are the benefits of Linked List over a cluster? 

The extent of a connected rundown can be augmented at runtime which is unthinkable on account of the exhibit.

The List isn't required to be coterminously present in the primary memory, if the touching space isn't accessible, the hubs can be put away anyplace in the memory associated through the connections.

The List is progressively put away in the principle memory and develops according to the program request while the cluster is statically put away in the fundamental memory, size of which must be announced at accumulate time.

The quantity of components in the connected rundown are restricted to the accessible memory space while the quantity of components in the exhibit is constrained to the span of a cluster.

24) Write the grammar in C to make a hub in the separately connected rundown. 

struct hub


int information;

struct hub *next;


struct hub *head, *ptr;

ptr = (struct hub *)malloc(sizeof(struct hub));

25) If you are utilizing C language to actualize the heterogeneous connected rundown, what pointer type ought to be utilized? 

The heterogeneous connected rundown contains diverse information types, so it is beyond the realm of imagination to expect to utilize normal pointers for this. For this reason, you need to utilize a conventional pointer type like void pointer in light of the fact that the void pointer is equipped for putting away a pointer to any kind.

26) What is doubly connected rundown? 

The doubly connected rundown is an unpredictable kind of connected rundown in which a hub contains a pointer to the past just as the following hub in the arrangement. In a doubly connected rundown, a hub comprises of three sections:

hub information

pointer to the following hub in arrangement (next pointer)

pointer to the past hub (past pointer).