100+ Megha Engineering & Infrastructures Interview Questions and Answers

The program reads a file and selects the first 3 lines. It then identifies the longest line and counts the number of words in that line.

• Read the file using appropriate file handling methods

• Store the first 3 lines in an array of strings

• Iterate through the array to find the longest line

• Count the number of words in the longest line using string manipulation methods

O(nk) is better than O(n) for large data and hash tables.

• O(nk) is better because it takes into account the size of the data and the number of keys.

• For large data and hash tables, the size of n will be large, making O(nk) more efficient.

• O(n) assumes a constant number of keys, which may not be the case in practice.

• Amazon may have chosen O(nk) for better scalability and performance.

Amazon displays only a subset of search results based on various factors like relevance, popularity, and user preferences.

• Amazon uses algorithms to determine which products to display in search results.

• Factors considered include product relevance, customer reviews, sales rank, and availability.

• Machine learning techniques may be used to personalize search results based on user behavior and preferences.

• Amazon also considers factors like seller reputation and fulfillment options...read more

The question is about finding the shortest path in a 3x3 matrix with weighted edges.

• This is a graph traversal problem.

• Use a graph algorithm like Dijkstra's algorithm or A* search to find the shortest path.

• Assign weights to the edges and calculate the sum of weights for each possible path.

• Choose the path with the smallest sum of weights as the shortest path.

A prime number is a number that is divisible only by 1 and itself.

• A prime number has exactly two factors: 1 and itself.

• Prime numbers cannot be divided evenly by any other number.

• Examples of prime numbers include 2, 3, 5, 7, 11, 13, 17, etc.

The product will be the key and the brands will be the values.

• The key in this case refers to the unique identifier for each product.

• The values are the different brands associated with each product.

• For example, if the product is a smartphone, the key could be the model number and the values could be the different brands that manufacture that model.

An e-cheque is an electronic version of a paper cheque that is used for making payments online.

• E-cheques are created and signed digitally, eliminating the need for physical paper.

• They are typically used for online transactions and can be deposited into a bank account electronically.

• The clearance time for e-cheques varies depending on the bank and the specific transaction.

• It can take anywhere from a few hours to several business days for an e-cheque to clear.

• During the clearan...read more

Spring Boot offers advantages like rapid development, easy configuration, embedded servers, production-ready features, and more.

• Rapid development: Spring Boot simplifies the setup and configuration of Spring applications, allowing developers to focus on writing business logic.

• Easy configuration: Spring Boot provides auto-configuration, reducing the need for manual setup and boilerplate code.

• Embedded servers: Spring Boot comes with embedded servers like Tomcat, Jetty, and Unde...read more

Radix sort is a sorting algorithm that sorts integers by processing individual digits from least significant to most significant.

• Radix sort is a non-comparative sorting algorithm.

• It sorts numbers by grouping them based on each digit's value.

• It is commonly used for sorting strings in lexicographic order.

• Radix sort has linear time complexity, making it efficient for large datasets.

Methods to find nth largest element in an unsorted linked list

• Traverse the linked list and store elements in an array, sort the array and return the nth largest element

• Use quickselect algorithm to find the nth largest element in O(n) time complexity

• Implement a max heap and extract the nth largest element

• Divide the linked list into smaller sublists and recursively find the nth largest element

• Use merge sort to sort the linked list and return the nth largest element

Hash tables are a data structure that uses a hash function to map keys to values, providing efficient lookup, insertion, and deletion.

• Hash tables use a hash function to convert keys into array indices.

• They provide constant-time average case complexity for search, insert, and delete operations.

• Collisions can occur when different keys map to the same index, which can be resolved using techniques like chaining or open addressing.

• Examples of hash table implementations include Pyt...read more

Hashing is a process of converting data into a fixed-size numerical value called a hash code.

• Hashing is used to quickly retrieve data from large datasets.

• It is commonly used in data structures like hash tables and hash maps.

• Hash functions should be fast, deterministic, and produce unique hash codes for different inputs.

• Examples of hash functions include MD5, SHA-1, and SHA-256.

The Fibonacci series can be applied in day-to-day life for various purposes.

• Financial planning: Fibonacci numbers can be used to calculate investment growth and determine optimal investment strategies.

• Architecture and design: Fibonacci ratios can be used to create aesthetically pleasing designs and layouts.

• Nature and biology: Fibonacci patterns can be observed in the growth of plants, arrangement of leaves, and formation of shells.

• Music and art: Fibonacci sequences can be use...read more

Object Oriented Programming is a programming paradigm that uses objects to represent real-world entities.

• Encapsulation: bundling data and methods that operate on that data within one unit

• Inheritance: creating new classes from existing ones, inheriting their properties and methods

• Polymorphism: ability of objects to take on multiple forms or behaviors

• Abstraction: hiding complex implementation details and providing a simplified interface

• Example: A car object can have properties ...read more

Design classes for educational institutions in a city

• Identify the main entities: schools, students, teachers, courses

• Create a School class with attributes like name, address, and a list of students and teachers

• Create a Student class with attributes like name, age, and a list of courses

• Create a Teacher class with attributes like name, specialization, and a list of courses

• Create a Course class with attributes like name, duration, and a list of students and teachers

• Establish rel...read more

The question asks for the number of pairs between 1 and N that satisfy a specific mathematical relation.

• The relation is pow(a,3) + pow(b,3) = pow(c,3) + pow(d,3)

• The values of a, b, c, and d should be less than or equal to N

• Count the number of pairs that satisfy the relation

Check if a given file path exists in the file system hierarchy and return the result.

• Use file system APIs to check if the given file path exists in the hierarchy.

• Traverse the file system hierarchy starting from the root directory to find the given file path.

• Return true if the file path exists, false otherwise.

Abstraction is hiding the implementation details, function overriding is providing a new implementation for a method in a subclass.

• Abstraction involves hiding the complex implementation details and showing only the necessary features to the user.

• Function overriding occurs in inheritance when a subclass provides a specific implementation for a method that is already defined in its superclass.

• Example: Parent class 'Animal' has a method 'makeSound()', subclass 'Dog' overrides th...read more

Test cases for a bank transaction

• Transaction amount within account balance limit

• Transaction amount exceeds account balance limit

• Transaction to a valid account number

• Transaction to an invalid account number

• Transaction with correct transaction code

• Transaction with incorrect transaction code

• Transaction during bank working hours

• Transaction outside bank working hours

Find subset of numbers in array that sum up to zero.

• Use a nested loop to iterate through all possible subsets.

• Calculate the sum of each subset and check if it equals zero.

• Store the subset if the sum is zero.

• Optimize the solution by using a hash set to store the cumulative sum of elements.

Finding optimal path cost and path in a matrix using dynamic programming.

• Dynamic programming is a technique to solve problems by breaking them down into smaller subproblems and solving them recursively.

• In this case, we can use dynamic programming to find the optimal path cost and path in a matrix.

• We can start by defining a 2D array to store the minimum cost of reaching each cell in the matrix.

• Then, we can use a recursive function to calculate the minimum cost of reaching the ...read more

Listen to their concerns, apologize, offer a solution, and follow up to ensure satisfaction.

• Listen actively to their concerns and empathize with their situation.

• Apologize for any inconvenience caused and take responsibility for the issue.

• Offer a solution that addresses their concerns and meets their needs.

• Follow up with the customer to ensure their satisfaction and address any further concerns.

• Document the issue and the steps taken to resolve it for future reference.

The boxes are labelled incorrectly with blue, green, and mixed balls. How many trials are needed to correctly label them?

• Start by picking a ball from the box labelled 'mixed'. Since all labels are incorrect, this ball must be either blue or green.

• Now, you can correctly label the box with the remaining two labels based on the color of the ball picked from the 'mixed' box.

• This can be done in just one trial by picking a ball from the 'mixed' box.

A recursive program to print numbers in ascending order

• Use a recursive function that takes a starting number and an ending number as parameters

• Print the starting number and recursively call the function with starting number + 1 and the same ending number

• Base case: stop recursion when starting number is greater than ending number

Dijkstra's algorithm finds the shortest path between nodes in a graph.

• Create a graph with nodes and edges

• Assign a tentative distance to each node

• Set the initial node as current and mark it visited

• For each neighbor of the current node, calculate the tentative distance

• If the tentative distance is less than the current distance, update the distance

• Mark the current node as visited and select the unvisited node with the smallest tentative distance

• Repeat until the destination node ...read more

Radix sort has a running time of O(nk), where n is the number of elements and k is the length of the longest element.

• Radix sort is a non-comparative sorting algorithm that sorts elements by their individual digits or characters.

• It works by distributing the elements into 10 buckets based on the value of the least significant digit, then repeatedly redistributing them based on the next significant digit.

• The process continues until all digits have been considered, resulting in a...read more

It is impossible to accurately determine the number of A4 sheets sold in India per day.

• There is no centralized data on the sales of A4 sheets in India.

• The number of A4 sheets sold can vary greatly depending on the region and industry.

• Factors such as digitalization and environmental concerns may also impact sales.

• Estimates or projections may be available from specific companies or industries.

• Market research firms may have data on the overall paper market in India.

A program to reverse a singly linked list

• Create a new empty linked list

• Traverse the original linked list and insert each node at the beginning of the new list

• Return the new list

Abstraction is hiding implementation details while polymorphism is using a single interface for multiple types.

• Abstraction: Encapsulation, Interfaces, Abstract classes

• Polymorphism: Method Overloading, Method Overriding, Interfaces

• Abstraction Example: Car - we don't need to know how the engine works to drive it

• Polymorphism Example: Animal - different animals have different sounds but they all have a 'makeSound' method

To find a cycle in a graph, use depth-first search (DFS) and keep track of visited nodes.

• Implement DFS algorithm to traverse the graph

• Maintain a visited array to keep track of visited nodes

• If a visited node is encountered again during DFS, a cycle exists

Shortest path problem is finding the shortest path between two nodes in a graph.

• It is a common problem in graph theory and computer science.

• Dijkstra's algorithm and Bellman-Ford algorithm are commonly used to solve it.

• The problem can be solved using dynamic programming and graph traversal techniques.

• Examples include finding the shortest route between two cities on a map or the shortest path for a robot to navigate a maze.

Track payment failure count and ensure fail safe measures

• Implement a system to track payment failure count in real-time

• Set up alerts for payment failures exceeding a certain threshold

• Automate retries for failed payments with back-off strategies

• Implement logging and monitoring to track payment failure trends

• Integrate with payment gateway APIs to handle failures gracefully

I worked as a data analyst, collecting, cleaning, and analyzing data to identify trends and make recommendations.

• Collected data from various sources such as databases, spreadsheets, and APIs

• Cleaned and organized data to ensure accuracy and consistency

• Performed statistical analysis to identify patterns and trends

• Created visualizations and reports to communicate findings to stakeholders

I am currently working on metrics such as first call resolution, average handling time, and customer satisfaction.

• First call resolution - ensuring that customer issues are resolved on the first call

• Average handling time - tracking the time it takes to resolve customer issues

• Customer satisfaction - measuring how satisfied customers are with the service provided