Quiz-O-Tech Final Round

The following adjacency matrix represents a graph with vertices A, B, C, and D. Identify the correct edges in the graph:

• A-B, A-C, B-C, C-D

• A-B, A-C, B-D, C-D

• A-B, A-D, B-C, B-D

• A-B, B-C, C-D, A-D

Based on the adjacency matrix:

How many edges are present in the graph?

• 2

• 3

• 4

• 5

You are given a table Employees with the following structure:

Write a query to rank employees by their salary within each department.

• SELECT

  Name,

  Salary,

  DENSE_RANK() OVER (ORDER BY Salary DESC) AS Rank

  FROM Employees;

• SELECT Department, Name, Salary, RANK() OVER (PARTITION BY Department ORDER BY Salary DESC) AS RankFROM Employees;

• SELECT Name, Salary, ROW_NUMBER() OVER (PARTITION BY Department ORDER BY Name) AS Rank FROMEmployees;

• SELECT Name, Salary, ROW_NUMBER() OVER (PARTITION BY Department ORDER BY Name) AS Rank FROMEmployees;

When designing a social media platform, you need to manage user profiles, posts, comments, and likes. The system should handle millions of users, and it must allow users to view posts and like them efficiently.

Which design approach will best ensure scalability and performance for this system?

• Use a relational database for storing all data

• Use a NoSQL database to handle high-volume, unstructured data

• Use an in-memory database for storing posts and likes

• Use file storage for storing posts and comments

What is the role of a "Spike" in Agile development?

• To allocate time for system testing

• To complete user stories in a single sprint

• To perform time-boxed research or investigation

• To handle integration between different modules

You are given an array nums consisting of positive integers. Starting with score = 0, the following algorithm is applied:

1. Choose the smallest integer of the array that is not marked. If there is a tie, choose the one with the smallest index.

2. Add the value of the chosen integer to the score.

3. Mark the chosen element and its two adjacent elements if they exist.

4. Repeat until all the array elements are marked.

What is the final score for the given array nums after applying the above algorithm?

Example 1:
Input: nums = [2, 1, 3, 4, 5, 2]
Options:
a) 7
b) 8
c) 6
d) 9

Example 2:
Input: nums = [2, 3, 5, 1, 3, 2]
Options:
a) 6
b) 5
c) 7
d) 4

• a) 7

  b)5

• b)8

  c)7

• a)7

  a)6

• None

Which of the following statements about CTEs (Common Table Expressions) is correct?

• They are permanent tables used for storing data temporarily.

• They are defined using the WITH keyword in SQL.

• They replace the need for indexes in complex queries.

• They are only used in distributed databases.

What is the purpose of database sharding?

• Ensuring data security

• Enabling horizontal partitioning for scalability

• Improving ACID compliance

• Optimizing indexing mechanisms

What is a critical technology in detecting and preventing cyberattacks by 2025?

• Quantum computing

• Artificial intelligence

• Blockchain

• 5G technology

Which of the following is the primary role of an operating system's kernel?

• Managing user interfaces

• Managing file systems

• Managing system resources like memory, processes, and I/O devices

• Managing network protocols