Data Structure Interview Questions

Data Structure interview questions

Do you think cracking an interview is difficult? Are you afraid of sitting in the interview rooms answering all the questions asked to you regarding data structure? If you are worried about cracking the interview as you think that your preparation is not up to the mark, then you can just follow our data structure interview questions. Our questions and answers are prepared by the experienced people who have the right amount of knowledge and expertise to answer all the questions appropriately. Just learn the answers and sit in the interview confidently, you will definitely crack the interview easily

About Data Structure

In the world of computer science, data structure basically is an organization of data, its management, and a type of storage format that allows efficient accesses and modifications to the users. More precisely, it is a collection of various data values, the relationships that they possess, and the types of functions or the kinds of operations that can be easily implemented to the data is known as a data structure. It is the way you can store and keep your data organized so that you can use it for a purpose efficiently.

Best Data Structure Interview Questions of 2020

1. What is data structure?

Data structure refers to the way data is organized and manipulated. It seeks to find ways to make data access more efficient. When dealing with the data structure, we not only focus on one piece of data but the different set of data and how they can relate to one another in an organized manner.

2. Differentiate between file and structure storage structure.

The key difference between both the data structure is the memory area that is being accessed. When dealing with the structure that resides the main memory of the computer system, this is referred to as storage structure. When dealing with an auxiliary structure, we refer to it as file structures.

3. When is a binary search best applied?

A binary search is an algorithm that is best applied to search a list when the elements are already in order or sorted. The list is searched starting in the middle, such that if that middle value is not the target search key, it will check to see if it will continue the search on the lower half of the list or the higher half. The split and search will then continue in the same manner.

4. What is a linked list?

A linked list is a sequence of nodes in which each node is connected to the node following it. This forms a chain-like link for data storage.

5. How do you reference all the elements in a one-dimension array?

To reference all the elements in a one -dimension array, you need to use an indexed loop, So that, the counter runs from 0 to the array size minus one. In this manner, You can reference all the elements in sequence by using the loop counter as the array subscript.

6. In what areas do data structures are applied?

 Data structures are essential in almost every aspect where data is involved. In general, algorithms that involve efficient data structure is applied in the following areas: numerical analysis, operating system, A.I., compiler design, database management, graphics, and statistical analysis, to name a few.

7. What is LIFO?

LIFO is a short form of Last In First Out. It refers how data is accessed, stored and retrieved. Using this scheme, data that was stored last should be the one to be extracted first. This also means that in order to gain access to the first data, all the other data that was stored before this first data must first be retrieved and extracted.

8. What is a queue?

A queue is a data structure that can simulate a list or stream of data. In this structure, new elements are inserted at one end, and existing elements are removed from the other end.

9. What are binary trees?

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

10. Which data structures are applied when dealing with a recursive function?

Recursion, is a function that calls itself based on a terminating condition, makes use of the stack. Using LIFO, a call to a recursive function saves the return address so that it knows how to return to the calling function after the call terminates.

11. What is a stack?

A stack is a data structure in which only the top element can be accessed. As data is stored in the stack, each data is pushed downward, leaving the most recently added data on top.

12. Explain Binary Search Tree

A binary search tree stores data in such a way that they can be retrieved very efficiently. The left subtree contains nodes whose keys are less than the node’s key value, while the right subtree contains nodes whose keys are greater than or equal to the node’s key value. Moreover, both subtrees are also binary search trees.

13. What are multidimensional arrays?   

Multidimensional arrays make use of multiple indexes to store data. It is useful when storing data that cannot be represented using single dimensional indexing, such as data representation in a board game, tables with data stored in more than one column.

14. How does dynamic memory allocation help in managing data?

Apart from being able to store simple structured data types, dynamic memory allocation can combine separately allocated structured blocks to form composite structures that expand and contract as needed.

15. What is FIFO?

FIFO stands for First-in, First-out, and is used to represent how data is accessed in a queue. Data has been inserted into the queue list the longest is the one that is removed first.

16. What is an ordered list?

An ordered list is a list in which each node’s position in the list is determined by the value of its key component, so that the key values form an increasing sequence, as the list is traversed.

17. What is shell sort?  

Shell sort can be said a variant of insertion sort. Shell sort divides the list into smaller sublist based on some gap variable and then each sub-list is sorted using insertion sort. In best cases, it can perform upto Ο(n log n).

18. How quick sort works?

Quick sort uses divide and conquer approach. It divides the list in smaller 'partitions' using 'pivot'. The values which are smaller than the pivot are arranged in the left partition and greater values are arranged in the right partition. Each partition is recursively sorted using quick sort.

19. What is a graph?

A graph is a pictorial representation of a set of objects where some pairs of objects are connected by links. The interconnected objects are represented by points termed as vertices, and the links that connect the vertices are called edges.

20. How depth first traversal works?

Depth First Search algorithm(DFS) traverses a graph in a depthward motion and uses a stack to remember to get the next vertex to start a search when a dead end occurs in any iteration.

21. How breadth first traversal works?

Breadth First Search algorithm(BFS) traverses a graph in a breadthwards motion and uses a queue to remember to get the next vertex to start a search when a dead end occurs in any iteration.

22. What is a tree? 

A tree is a minimally connected graph having no loops and circuits.

23. What is a binary tree?

A binary tree has a special condition that each node can have two children at maximum.

24. What is a binary search tree?

A binary search tree is a binary tree with a special provision where a node's left child must have value less than its parent's value and node's right child must have value greater than it's parent value.

25. What is an AVL Tree? 

AVL trees are height balancing binary search tree. AVL tree checks the height of left and right sub-trees and assures that the difference is not more than 1. This difference is called Balance Factor.

BalanceFactor = height(left-sutree) − height(right-sutree)

26. What is a spanning tree?

A spanning tree is a subset of Graph G, which has all the vertices covered with minimum possible number of edges. A spanning tree does not have cycles and it can not be disconnected. 

27. How many spanning trees can a graph has?

It depends on how connected the graph is. A complete undirected graph can have maximum nn-1 number of spanning trees, where n is number of nodes.

28. How Kruskal's algorithm works? 

This algorithm treats the graph as a forest and every node it as an individual tree. A tree connects to another only and only if it has least cost among all available options and does not violate MST properties.

29. How Prim's algorithm finds spanning tree?

Prim's algorithm treats the nodes as a single tree and keeps on adding new nodes to the spanning tree from the given graph.

30. What is a minimum spanning tree (MST)? 

In a weighted graph, a minimum spanning tree is a spanning tree that has minimum weight that all other spanning trees of the same graph.

Career scopes and salary scale

With the technological industry enhancing its features and specifications every single day to offer the best service to the users, the career opportunities and the scopes this field has is incredible. If you want to earn lakhs per month in the future stage, this career option has the ability to make you earn so much money at a certain point in time of your life. As mentioned, you get a scope to earn lakhs of money per month in the future, it also depends on the skillsets you have. For a fresher, he or she can earn up to 50,000 to 60,000 dollars per annum initially, while after gaining experience in the field, he or she can earn up to 90,000 to 100,000 dollars per annum.

Conclusion

With the help of our data structure interview questions, you will not only crack the interview but also you will open the doors of a beautiful career waiting for you. You can also message us at any given time in order to ensure that all your queries and questions are addressed and cleared.

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