Top 15 Data Structure & Algorithms Interview Questions 2022

Summary A data structure is a location that is used to store and organize data. Data structures and algorithm questions are the main part of any programming job interview. This blog will be describing your top 15 data structure and algorithms questions which are given below. The interview is essential for all to get a good job in the future. Preparing for an interview is the first step for anyone who wants to get the job. Always knowing concepts and questions about interview sessions is important. Data structures and algorithm questions are the main part of any programming job interview. For example, a Java interview, a C++ interview, and other programming languages. As many data structures, interview questions can be asked but we gather the top 15 questions mainly for learning and preparing purposes.  

1. Describe the two types of data structures

Linear Data Structure: When all of its components are organized in a proper sequence, a data structure is called linear. Non-linear data structure: The Non-linear data structure does not form a series, i.e., each object or entity is linked to two or more than two objects in a non-linear manner.

2. Explain the different operations that can be carried out on data structures

The different operations that are generally carried out in Data Structures are Insert, Delete, Traverse, Search, and Sort.

3. What do you understand by stack? Please explain some of its applications.

Stack is a linear data structure to access components that implement either LIFO (Last in First Out) or FILO (First In Last Out) method. The common functions of a stack are push, pop, and peek.

4. Describe the Concept of a Queue. How can you differentiate it from a Stack?

A queue is a type of linear structure that is used to access components that support the FIFO (First in First Out) method.

5. How you can differentiate between PUSH & POP

The functions PUSH and POP determine how to store and retrieve data in a stack.

• PUSH: PUSH determines the “insertion” of data into a stack.
• POP: POP specifies retrieval of the data. This means data is removed from the stack.

6. What do you understand by Data Abstraction?

Data abstraction helps to divide complicated data tasks into small, easily manageable components.

7. How many approaches are there for writing an Algorithm?

There are 3 widely used approaches to develop the algorithms-

• Greedy approach − Seeking a solution by picking the next best possible alternative.
• Divide and conquer − Bringing the problem to a minimal feasible sub-problem and separately solving it.
• Dynamic programming − Bringing the problem to a minimal possible sub-problem and solving them together.

8. Describe the Steps Involved in the Insertion

Algorithms of PUSH operations

• Step 1: Start
• Step 2: Checks if the stack is full if(top==(SIZE-1))
• Step 3: If the stack is full, Give a message and exit printf("\nStack Overflow");
• Step 4: If the stack is not full, increment top to point next empty space.
• top=top+1;
• Step 5: Add the data element to the stack location, where the top is pointing.
• printf("\nEnter the item to be pushed in stack:"); stack[top]=item;
• Step 6: Stop

9. Explain Linear Searching

Linear search aims to locate an object in a sequentially arranged data type. These sequentially arranged data items known as an array are accessible in incrementing memory location.

10. What is Binary Search?

A binary search only operates on sorted lists or arrays. This search chooses the middle which divides the whole list into two sections.

11. What do you understand by Array and Multidimensional Array?

Arrays are characterized as the gathering of similar types of data items stored at contiguous memory locations. The multidimensional array can be known as the array of arrays which takes the form of rows and columns wherein the data is kept in tabular form.

12. Can you explain the difference Between a Linked List and an Array?

Linked List is an ordered collection of elements of the same type in which each element is connected to the next using pointers An array is a collection of elements of a similar data type.

13. Explain the Process of Hashing

The technique of transforming a set of key values into a collection of array indexes is hashing.

14. What do you understand by a Spanning tree?

A spanning tree is a subset of a graph that has all the vertices but with the minimum number of edges necessary.

15. Give names of all the trees

General Tree, Forests, Binary Search Tree, Tournament Tree, Binary Tree, and Expression Tree Lastly, you need to stay focused and be self-confident. The aim is to earn learn but not to impress the interviewer. Another thing is dress up according to the role you have been applying for. Be dressed in proper formals, look good, and sound good. Be there before schedule, and try to not be nervous or don’t be late as punctuality is important for the interview.