20+ Amara Raja Infra Interview Questions and Answers

Find missing and repeating element in an array of 1 to n elements in O(n) time and O(1) space.

• Iterate through the array and for each element, mark the element at index equal to its value as negative. If the element is already negative, it is the repeating element.

• After marking all elements, the positive element's index + 1 is the missing element.

• Example: Array ['1', '2', '3', '3', '5'] - Repeating element is '3' and missing element is '4'.

Creating two threads and synchronizing them in a multi-threaded example.

• Create two threads using the Thread class in Java.

• Implement the run() method for each thread.

• Use synchronized keyword to ensure thread safety.

• Example: Thread t1 = new Thread(new MyRunnable()); t1.start();

• Example: Thread t2 = new Thread(new MyRunnable()); t2.start();

Find the second greatest element in an array without sorting using C++ concepts.

• Iterate through the array to find the greatest element.

• While iterating, keep track of the second greatest element.

• Return the second greatest element once the iteration is complete.

Count nodes in a binary tree without using recursion

• Use a stack to keep track of nodes to visit

• Pop nodes from the stack and increment count for each node visited

• Continue until stack is empty

Find the longest subsequence in a string without repeating characters.

• Use a sliding window approach to keep track of the characters seen so far.

• Update the start index of the window when a repeating character is encountered.

• Keep track of the longest subsequence length seen so far.

Producer consumer problem solution code

• Use synchronized keyword or locks to ensure thread safety

• Use wait() and notify() methods to coordinate between producer and consumer threads

• Use a shared buffer to store data produced by producer and consumed by consumer

• Example: https://www.geeksforgeeks.org/producer-consumer-solution-using-threads-java/

Rotate k elements to the right in an array

• Create a new array with the same length as the original array

• Copy elements from the original array to the new array starting from index (k % array length)

• Copy remaining elements from the original array to the new array

• Return the new array as the rotated array

Find the longest palindromic substring in a given string.

• Use dynamic programming to check if substrings are palindromes.

• Start with single characters as potential palindromes and expand outwards.

• Keep track of the longest palindrome found so far.

Merge two sorted LinkedList into a Sorted LinkedList.

• Create a new LinkedList to store the merged result.

• Iterate through both input LinkedLists and compare values to insert into the new LinkedList.

• Handle cases where one LinkedList is longer than the other.

• Time complexity should be O(m+n) where m and n are the lengths of the input LinkedLists.

Consumer producer multithreading program involves multiple threads sharing a common buffer to produce and consume data.

• Use synchronized data structures like BlockingQueue to handle thread synchronization.

• Implement separate producer and consumer classes with run methods.

• Use wait() and notify() methods to control the flow of data between producer and consumer threads.

Expected compensation should be based on industry standards, experience, skills, and location.

• Research industry standards for Senior Software Engineer salaries

• Consider your level of experience and skills

• Take into account the cost of living in the location of the job

• Negotiate based on your value to the company

Sort an integer array with only 0 and 1

• Iterate through the array and count the number of 0s and 1s

• Update the array with the correct number of 0s and 1s based on the counts

• Time complexity should be O(n)

Implemented a microservices architecture using Docker and Kubernetes for scalability and reliability.

• Used Docker containers to encapsulate each microservice for easy deployment and scaling.

• Utilized Kubernetes for automated container orchestration and management.

• Implemented service discovery and load balancing for seamless communication between microservices.

Inheritance in OOP allows a class to inherit properties and behaviors from another class.

• Inheritance promotes code reusability by allowing a new class to use the properties and methods of an existing class.

• The class that is being inherited from is called the base class or parent class, while the class that inherits is called the derived class or child class.

• Derived classes can add new properties and methods, or override existing ones from the base class.

• Example: class Animal ...read more

System design for small systems involves creating a high-level architecture to meet specific requirements.

• Identify the requirements and constraints of the system

• Break down the system into smaller components/modules

• Design the interactions between components

• Consider scalability, reliability, and performance

• Choose appropriate technologies and frameworks

• Document the design for future reference

Code for atoi function

• Loop through the string and convert each character to its integer value

• Multiply the current result by 10 and add the integer value of the current character

• Handle negative numbers and invalid input

System design of command service involves designing a system that can handle and execute commands efficiently.

• Define the requirements for the command service, including supported commands and expected response times.

• Design a scalable architecture that can handle a large number of concurrent commands.

• Implement a command queue to manage the order of execution and prevent conflicts.

• Consider implementing a retry mechanism for failed commands to ensure reliability.

• Use appropriate ...read more

Sort an array of strings containing '0', '1', and '2'.

• Use counting sort algorithm to count the occurrences of '0', '1', and '2'.

• Create a new array based on the counts of each element.

• Return the sorted array.

Designing a quick ecommerce site involves creating a user-friendly interface with easy navigation and secure payment options.

• Focus on a clean and intuitive user interface

• Implement a robust search functionality for products

• Include secure payment gateways like PayPal or Stripe

• Optimize site speed for quick loading times

• Ensure mobile responsiveness for on-the-go shopping

• Integrate customer reviews and ratings for trust-building

• Implement a user-friendly checkout process with guest ...read more

Polyfill for array map function in JavaScript

• Create a function called myMap that takes a callback function as an argument

• Loop through the array and apply the callback function to each element

• Return a new array with the results of the callback function applied to each element