Top Data Structures Interview Questions And Answers

As demand for website developers, data scientists, or software developers, in the work market has expanded, some recruiting managers have become interviewing specialists, so it is significant for you to get ready to guarantee you prevail during your following Data Structures Interview Questions.

It’s important to understand, ‘what is a data structure?” or what are data structures?

Organizing data’s that is stored in a computer or database becomes challenging without the knowledge of a good data structure.

Any issues require illustrating a profound knowledge of data structures of professional experience count. Whether a website developer, a data scientist or a software developer, you should learn data structures and algorithms to brush skills twice the better.

Coming up next are some regularly posed Data Structures Interview Questions, especially for a candidate aspiring to crack the interview in first attempt.

List of Top 25 Data Structures Interview Questions And Answers

The data structures of interview questions and answers will draw ideas on question type to expect. It is an increasing advantage to get familiar with topic and how to give answers of the questions accordingly. Through this, you can enhance your knowledge of the specific topics expected in the interview.

As they say, champions are brilliant as the basics goes by. Nonetheless, the viva can be derived from diverse topics apart from basics of data structures within the niche.

Let’s get prepare with the frequently asked data structures Interview questions and answers:

Basic Data Structures Interview Questions And Answers

1) What is data structure?

A data structure is a set of procedures to define, store, access, and manipulate data. For instance; arrays, linked lists, stacks, queues, etc. Data Structures are an integral part of multiple computer science algorithms that enable the management of data in a systematic way.

2) Describe the types of data structures.

The data structures fall into two types:

Linear Data Structure: A data structure where all the data elements or item are arranged in a linear order where each element are connected to its previous and next adjacent. The single level of data structure is widely used in application software development

Examples include; Arrays, stacks, queues, and link lists.

Non-Linear Data Structure: A non-linear data structure is where all the data elements are joined in a hierarchical order. With involving multiple-level data structuring, it is used for Artificial intelligence and image processing.

Examples include; Trees, and graphs.

3) Is an array a data structure?

An array is a linear data structure that is a determination collection of similar data types and stores in previous or successive memory locations. For instance; an array cannot contain either character elements or integers together.

This is one of the common questions of basic data structures.

4) List the area of applications of Data Structure.

Following are the areas of computer science where data structures are applied:

- Artificial Intelligence

- Compiler Design

- Database Management System

- Graphics

- Numerical Analysis

- Operating System

- Simulation

- Statistical Analysis Package

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

The lists below entail the list of data structures used:

- RDBMS uses an Array data structure,

- Network data model uses Graph,

- Hierarchal data model uses Trees.

6) What are the operations that can be performed on a stack?

- Push Operations

- Pop Operations

- Peek Operations

7) What is the difference between PUSH and POP?

The PUSH and POP designate the entry and removal of data to a stack.

PUSH: It specifies that data is being "inserted" into the stack.

POP: It specifies data retrieval. It means that data is being deleted from the stack.

8) What is stack example?

For example, a pile of plates, a deck of cards, a stack of plates, etc.  A stack is called a last in first out (LIFO) list. The last element is the first to be taken out.

9) List the types of tree.

It entails six types of tree which include:

- Binary Tree

- Binary Search Tree

- Expression Tree

- Forests

- General Tree

- Tournament Tree

10) What is a One dimensional array?

A One-Dimensional array is a linear structure of components that stores the same type of data values referred to by the same name using one variable.

11) What is stack and queue?

Stack represents the collection of elements in Last In First Out (LIFO). The insertion operation is called push operation.

Whereas, a queue is the representation of the collection of elements in First In First Out  (FIFO). The insertion operation is called Enqueue operation.

12) What is Big O function?

Big O Notation is a theoretical measure to check a computer algorithm's efficiency as the inputs start to increase. It describes algorithm complexity.

There are two sections to measure the efficiency used in memory by an algorithm i.e., time complexity and space complexity.

13) What are the types of arrays?

Arrays are categorized into three different types:

- One dimensional array

- Two dimensional array

- Three dimensional array

14) Why array is not a data type?

Arrays are regular objects. In Javascript, there are only six data types and an array is an indexed finite data element that does not belong to this list because they are regular objects as well.

15) What is a stack data structure?

A stack is a data structure as it stores data entries that can later be recovered in the reverse or LIFO (Last In First Out). The last data element contained in a stack is detached first and the rest follows.

For instance; a stack data structure can as be a pile of plates on top of another.

16) Is queue LIFO or FIFO?

A queue is a FIFO data structure type.

17) Why stack is called LIFO list?

When an inserted element at the top is also the element to be removed first from the stack by the operations (insert and delete in a stack, which is why the stack is called a Last In First Out (LIFO) list.

18) What are the 6 applications of stack?

The various applications of stack are as follows;

- Expression Conversion

- Expression Evaluation

- Passing well-formed (nested)

- Decimal to binary conversions

- Reverse a string

- Simulate Recursions

- Convert infix expression to postfix and prefix expressions

- Backtracking algorithms

19) What are the types of queues?

There are four different types of queues:

- Simple Queue

- Circular Queue

- Priority Queue

- Double Ended Queue

20) Is the JVM stack based?

The JVM (Java Virtual Machine) is a stack-based virtual machine where all the arithmetic and logic operations carry through push and pop methods and the outcome is contained on the stack.

21) What is heap in Java?

A heap is a balanced specialized tree-based data structure in which the root node is compared with the child node to arrange it accordingly.

It is a non-linear data structure where the memory is distributed in a random manner.

22) What is stored in heap?

The heap memory stores all the variables or object values. But, the stack holds any object reference which is an address to the location of the object kept in the heap memory.

23) What is thread in Java?

A thread is a basic unit of CPU utilization that allows multiple activities to coexist within a single process.

24) What is a link list?

A link list is a sequence of nodes in which each and every node is connected to the node following, which forms a chain-like link of data storage.

25) What are binary trees?

A binary tree is a type of data structure that has two nodes, a left node and a right node. In programming, binary trees are actually an extension of the linked list structures.

26) Classify the hashing functions based on the various methods by which the key value is found.

- Direct method

- Substraction method

- Midulo-Divison method

- Digit-Extraction method

- Mid-square method

- Folding method

- Psuedo-random method

27) Write the C code to perform in-order traversal on a binary tree.

Conclusion

An efficient program executes faster and reduces the usage of resources like memory or disk.

Computers are getting more compelling with the time passage which makes data structures, even more, to rely on.

With the curated interview questions on data structures, it aids candidates to breakdown with strategizing any exam. All the best!

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