# Data Structures Interview Questions (Part-2) | Read Now

Data Structures (DS) in the computer sector make up an essential part for understanding the basic operations of lists, stacks, and so on.

In this post, the top asked interview questions based on Data Structures are displayed to shine-up your skills and make you capable of cracking the interview for job or internship smoothly.

**16] Brief on the numerous sorts of Notations found in DS.**

- In DS, there exists 3 sorts of notations:
- Infix: In this, the operators are positioned between the respective operands
- Prefix/Polish: In this, the operators are positioned before-hand the respective operands
- Postfix/Reverse: In this, the operators are positioned after-hand the respective operands

#Infix notation X+Y #Prefic notation +XY #Postfix notation XY+

**17] Brief on the terminology “Binary-tree” DS.**

- Binary-tree DS is a hierarchical topological DS wherein a root or parent or super node contains either 2 child elements/nodes on the both sides which are left plus right.
- They are also abbreviated as extended linking list.

**18] Elaborate the procedure for storing/saving some variable in computer’s memory.**

- Depending on the volume of space demanded, a variable is maintained in memory-space.
- The stages for preserving the variable are as regards:
- Firstly, the appropriate quantity of RAM is allocated.
- The information is then recorded employing DS that was configured.
- Any use of ideas such as allocation offers excellent productivity and that storage tanks can be utilized in real environments accordance with the needs.

**19] How “Void” differs from that of “Null” in DS?**

- In DS, void is a primitive data identifier, although null is a quantity which has no strong existence.
- When void is employed to initialize a DS, it means that there may be no dimension of DS earlier.

**20] How can one validate if a specified Binary-tree DS is whether or not BST?**

- If a binary-tree’s in-order sort traversal is categorized, that tree is BST.
- The intention is to execute in-order traversing and retain record of the preceding core value while doing so.
- Repeat if the key value is larger; or return False.

**21] Brief on “Merge” Sorting found in DS.**

- Merge sorting is a filtering methodology relied on the divide – and – conquer principle.
- Each iteration, information entities that are near to others are first combined and sorted to construct categorized lists.
- At the closing, these tiny ordered listings are concatenated to make the entirely ordered listing.

**22] Elaborate a sort of queue namely “Priority-queue” found in DS.**

- A priority-queue is an abstract model that is equivalent to an ordinary queue but incorporates entries with distinct needs.
- Relatively high elements are evaluated first, followed by lowest priority entities.
- A minimum of 2 queues are required to develop this, including one for data and one for storing ranking.

**23] Brief on the work-flow of “Selection Sorting” in DS.**

- In the domain of Data Structures, a selection sorting is an extensively employed sorting methodology.
- The mechanism is concise: the tiniest object is discovered first, and its index is set to 0, effectively sorting it in the top step.
- The necessary process entail iterating through the remaining parts and appending its next index if applicable.
- This procedure is iterated until all of the parts have been filtered.

**24] Point-out the usage of Graph DS.**

- To evaluate the information flow in popular network sites such as Instagram, LinkedIn, and others, social media network graphs are employed.
- Nodes presents neurons, while edges signify interconnections among them and neural net graphs.
- Terminals are the endpoints and paths are the chart’s corners in transfer grids.
- Graphs of energy or water-utility interconnections, with vertices representing connecting locations and edges representing the wiring or pipes that join them.
- Mechanisms for reducing travel distance between two ending locations.

**25] Brief on “Deque” terminology found in DS.**

- A double ending DS queue is characterized as a deque.
- This implies any of the opposite edges can have components appended or eliminated. It can be employed as a stacking or as a conventional queue.
- In practice, it surpasses both linking lists and stacking.

**26] Point-out the sorts of Trees found in DS.**

- Forest
- Binary
- Conventional
- Tournament
- Expression

**27] How can one evaluate whether to employ DFS or BFS in specific incident?**

- A BFS may be advantageous if the response is expected to be close to the tree’s base.
- DFS may consume a lot of time if the tree is very extensive and answers are few, however BFS may be speedier.
- A BFS may demand too much storage if the tree is too massive, making it entirely unfeasible. In these instances, we opt for DFS.
- If solutions are several but deeper in the tree, DFS is the way to go.

**28] Elaborate on Heap DS sorts.**

**Maximal Heap:**In a Max-Heap, the data object at the base station is the most meaningful of all the data in the graph.- This characteristic must be applicable for all semi-trees of that tree structure recursively.
**Minimal Heap:**In a Min-Heap, the data object at the parent node must be the tiniest of all records in the graph.- This characteristic should be applicable for all semi-trees of that tree structure recursively.

**29] Point-out merits of “Selection” Sorting found in DS.**

- Easier and convenient
- 60% productive than Bubble-sorting
- Perfect for tiny metadata

**30] Amongst all, RDBMS and Hierarchical models employ which DS?**

- RDBMS employs Array DS and Hierarchical model employs Tree DS.