90+ Hindustan Aeronautics Interview Questions and Answers

Check if a given word is present in a sentence as a complete word.

• Split the sentence into words using spaces as delimiter.

• Check if the given word matches any of the words in the sentence.

• Ensure the word is not just a substring of another word in the sentence.

The problem involves finding the minimum distance between the closest pair of points in a 2D plane.

• Iterate through all pairs of points and calculate the distance between them using the given formula.

• Keep track of the minimum distance found so far.

• Optimize the solution by using techniques like sorting the points based on x or y coordinates.

Given a grid with type A and B people, maximize satisfaction based on neighbors.

• Start with type A people for maximum satisfaction

• Optimally place people to maximize satisfaction

• Consider satisfaction levels for each type of person and their neighbors

To detect the first node of a loop in a singly linked list, we can use Floyd's Cycle Detection Algorithm.

• Use Floyd's Cycle Detection Algorithm to detect the cycle in the linked list.

• Once the cycle is detected, find the starting node of the cycle using two pointers approach.

• The first pointer moves one step at a time while the second pointer moves two steps at a time until they meet at the starting node of the cycle.

Find the maximum sum of a subsequence without choosing adjacent elements in an array.

• Use dynamic programming to keep track of the maximum sum at each index, considering whether to include the current element or not.

• At each index, the maximum sum can be either the sum of the current element and the element two positions back, or the maximum sum at the previous index.

• Iterate through the array and update the maximum sum accordingly.

• Example: For the input [3, 2, 7, 10], the maxim...read more

Reverse a singly linked list of integers and return the head of the reversed linked list.

• Iterate through the linked list and reverse the pointers to point to the previous node instead of the next node.

• Use three pointers to keep track of the current, previous, and next nodes while reversing the linked list.

• Update the head of the reversed linked list as the last node encountered during the reversal process.

Find the greatest common divisor (GCD) of two given numbers 'X' and 'Y'.

• Implement a function to calculate GCD using Euclidean algorithm

• Iteratively find the remainder of X divided by Y until Y becomes 0

• The last non-zero remainder is the GCD of X and Y

The N Queens Problem involves finding all possible placements of N queens on an N x N chessboard without threatening each other.

• Use backtracking algorithm to explore all possible configurations.

• Keep track of rows, columns, and diagonals to ensure queens do not threaten each other.

• Generate all valid configurations and print them out.

Sort an array of 0s, 1s, and 2s in linear time complexity using a single scan.

• Use three pointers to keep track of the positions of 0s, 1s, and 2s in the array.

• Iterate through the array and swap elements based on their values and the pointers.

• After a single scan, the array will be sorted in-place with 0s, 1s, and 2s in order.

Find the inorder successor of a given node in a binary tree.

• Perform an inorder traversal of the binary tree to find the successor node

• If the given node has a right child, the successor is the leftmost node in the right subtree

• If the given node does not have a right child, backtrack to find the ancestor whose left child is the given node

Boundary traversal of a binary tree to find left boundary, right boundary, and leaf nodes in an anti-clockwise direction.

• Perform a pre-order traversal to get the left boundary nodes

• Perform an in-order traversal to get the leaf nodes

• Perform a post-order traversal to get the right boundary nodes

• Combine the results in the required order to get the boundary nodes

Add two numbers represented as linked lists and return the sum as a linked list.

• Traverse both linked lists simultaneously while keeping track of carry from previous sum

• Handle cases where one linked list is longer than the other by padding with zeros

• Create a new linked list to store the sum of the two numbers

Implement a stack with getMin operation in O(1) time complexity without using extra space.

• Use two stacks - one to store the actual elements and another to store the minimum values encountered so far.

• When pushing an element, check if it is smaller than the current minimum and if so, push it onto the minimum stack.

• When popping an element, check if it is the current minimum and if so, pop from the minimum stack as well.

• For getMin operation, simply return the top element of the m...read more

Generate all possible combinations of balanced parentheses for a given number of pairs.

• Use backtracking to generate all valid combinations of balanced parentheses.

• Keep track of the number of open and close parentheses used in each combination.

• Recursively build the combinations by adding open parentheses if there are remaining, and then adding close parentheses if the number of open parentheses is greater than the number of close parentheses.

• Return the list of valid combinatio...read more

Sort a stack in descending order using recursion without using loop constructs.

• Implement a recursive function to sort the stack in descending order.

• Use the provided stack operations to manipulate the stack.

• Recursively pop elements from the stack, sort them, and push them back in descending order.

• Handle base cases such as an empty stack or a single element stack.

• Ensure the stack is sorted in descending order after the recursive calls.

• Avoid using loop constructs like while or f...read more

Find the Lowest Common Ancestor (LCA) of two nodes in a binary tree.

• Traverse the binary tree to find the paths from the root to nodes X and Y.

• Compare the paths to find the last common node, which is the LCA.

• Handle cases where one node is an ancestor of the other.

• Consider edge cases like when X or Y is the root node.

• Implement a recursive or iterative solution to find the LCA efficiently.

The problem requires returning an array where each element is the product of all elements in the input array except itself.

• Iterate through the array twice to calculate the product of all elements to the left and right of each element.

• Use two arrays to store the products to the left and right of each element.

• Multiply the corresponding elements from the left and right arrays to get the final product array.

• Handle integer overflow by taking modulo MOD = 10^9 + 7.

• To solve with O(1...read more

Design a Least Recently Used (LRU) cache data structure that supports get and put operations with capacity constraint.

• Implement a doubly linked list to keep track of the order of keys based on their recent usage.

• Use a hashmap to store key-value pairs for quick access and update.

• When capacity is reached, evict the least recently used item before inserting a new item.

• Update the order of keys in the linked list whenever a key is accessed or updated.

• Handle get and put operations ...read more

Delete a specific node from a singly linked list given the reference to the node.

• Traverse the linked list to find the node to be deleted.

• Update the pointers to skip over the node to be deleted.

• Print the modified linked list after deletion.

Implement insertion sort algorithm on a singly linked list.

• Traverse the linked list and for each node, find its correct position in the sorted list.

• Keep track of the current node and the previous node to perform the insertion.

• Repeat this process until all nodes are sorted in the linked list.

• Ensure to handle edge cases like empty list or list with only one node.

Find the number of states of cities connected by roads in a matrix.

• Identify connected cities using DFS or Union-Find algorithm

• Count the number of disjoint sets to determine the number of states

• Handle self-connections of cities by setting roads[i][i] = 1

Generate all valid parentheses combinations for N pairs.

• Use backtracking to generate all possible combinations of parentheses.

• Keep track of the number of open and close parentheses used.

• Add '(' if there are remaining open parentheses, and add ')' if there are remaining close parentheses.

• Stop when the length of the generated string is 2*N.

Count the total number of unique pairs in an array whose elements sum up to a given value.

• Use a hashmap to store the frequency of each element in the array.

• Iterate through the array and for each element, check if (Sum - current element) exists in the hashmap.

• Increment the count of pairs if the complement exists in the hashmap.

• Divide the count by 2 to avoid counting duplicates like (arr[i], arr[j]) and (arr[j], arr[i]) separately.

Return all permutations of a given string in lexicographically increasing order.

• Generate all permutations of the given string using backtracking.

• Sort the permutations in lexicographical order.

• Print the sorted permutations separated by space.

To design a website displaying top 1000 products with real-time rating updates, use a combination of backend and frontend technologies.

• Implement a backend system to fetch and update product ratings from a database or API.

• Use a frontend framework like React or Angular to create a dynamic user interface.

• Implement pagination or lazy loading to handle the large number of products.

• Optimize the website for performance by caching frequently accessed data.

• Consider using websockets or...read more

Given an array of integers and a target sum, find the minimum number of operations to make the sum of removed elements equal to the target.

• Iterate from both ends of the array, removing elements until the sum matches the target

• Use a two-pointer approach to efficiently find the minimum number of operations

• If achieving the target sum is not possible, return -1

The task is to find the diameter of a binary tree, which is the longest path between any two nodes in the tree.

• Traverse the tree to find the longest path between two nodes.

• Keep track of the maximum diameter found during traversal.

• The diameter may or may not pass through the root node.

• Consider the height of the left and right subtrees to calculate the diameter.

Identify all distinct triplets within an array that sum up to a specified number.

• Iterate through the array and use nested loops to find all possible triplets.

• Use a set to store unique triplets and check if the sum equals the target.

• Handle edge cases like duplicate elements and no valid triplets.

• Return the triplets as space-separated integers or -1 if no triplets exist.

Find the median of two sorted arrays by merging them and calculating the median of the combined array.

• Merge the two sorted arrays into one sorted array.

• Calculate the median of the merged array based on the total number of elements.

• If the total number of elements is even, take the mean of the two middle elements as the median.

Count the number of islands in a 2D matrix of 1s and 0s.

• Use Depth First Search (DFS) or Breadth First Search (BFS) to traverse the matrix and identify connected groups of 1s.

• Maintain a visited array to keep track of visited cells to avoid redundant traversal.

• Increment the island count each time a new island is encountered.

• Consider edge cases like boundary conditions and handling of diagonals while traversing.

• Handle the input matrix efficiently to optimize the solution.

• Example...read more

Given a string, find the longest palindromic substring, prioritizing the one with the smallest start index.

• Iterate through the string and expand around each character to find palindromes

• Keep track of the longest palindrome found and its starting index

• Return the longest palindromic substring with the smallest start index

The objective is to minimize total penalty by selecting two numbers, summing them, and accumulating the penalty until only one number remains.

• Iteratively select two numbers, sum them, and accumulate the penalty until only one number remains.

• Choose the two smallest numbers to minimize the penalty.

• Repeat the process until only one number remains to find the minimum possible penalty.

Implement a stack using two queues to store integer values.

• Use two queues to simulate stack operations efficiently.

• Maintain the top element in one of the queues for easy access.

• Ensure proper handling of edge cases like empty stack.

• Example: Push elements onto one queue, then dequeue and enqueue to the other queue for pop operation.

• Example: Use a flag to track the top element and update it accordingly.

Use sliding window technique to find smallest subarray with k distinct values.

• Use a sliding window approach to keep track of the subarray with k distinct values.

• Use a hashmap to store the frequency of each element in the window.

• Slide the window to the right until the hashmap contains k distinct elements.

• Shrink the window from the left while maintaining k distinct elements.

• Update the minimum subarray length as you slide the window.

• Return the smallest subarray length found.

• Exam...read more

Find the Kth largest element in an array of distinct positive integers.

• Sort the array in non-increasing order and return the Kth element.

• Use a priority queue or quick select algorithm for efficient solution.

• Handle constraints like array size and element values properly.

• Ensure all elements in the array are distinct for accurate results.

Rearrange the nodes of a singly linked list in a specific order without altering the data of the nodes.

• Use two pointers to split the linked list into two halves, reverse the second half, and then merge the two halves alternately.

• Ensure to handle cases where the number of nodes is odd or even separately.

• Time complexity: O(N), Space complexity: O(1)

• Example: Input: 1 -> 2 -> 3 -> 4 -> 5 -> NULL, Output: 1 -> 5 -> 2 -> 4 -> 3 -> NULL

Find duplicates in an array of integers within a specified range.

• Iterate through the array and keep track of the count of each element using a hashmap.

• Return elements with count greater than 1 as duplicates.

• Time complexity can be optimized to O(N) using a set to store duplicates.

Design a website to display top 1000 products with real-time ratings.

• Utilize a backend server to fetch and update product ratings every second.

• Implement a front-end framework like React to display the products and ratings dynamically.

• Use a database to store and retrieve product information efficiently.

• Consider implementing caching mechanisms to reduce server load.

• Optimize the website for performance to handle frequent updates and large data sets.

Implement a specialStack class with O(1) push, pop, and minimum element retrieval.

• Use an additional stack to keep track of the minimum element at each step.

• When pushing an element, compare it with the top of the minimum stack and update if necessary.

• When popping an element, also pop from the minimum stack if the popped element is the current minimum.

Find a pair of integers in an array whose sum is equal to a given number.

• Iterate through the array and for each element, check if the difference between the given number and the current element exists in the array.

• Use a hash set to store the elements of the array for efficient lookup.

• Return the pair of integers if found, otherwise return a message indicating no such pair exists.

Design a system like Pastebin for sharing text snippets

• Use a web application framework like Django or Flask for the backend

• Store text snippets in a database with unique URLs for each snippet

• Implement user authentication and permissions for private and public sharing

• Include features like syntax highlighting, expiration dates, and password protection

• Optimize for fast and efficient text retrieval and storage

To determine the top 3 fastest horses out of 25, race horses in groups of 5 and keep track of the fastest horses in each race.

• Divide the 25 horses into 5 groups of 5 horses each.

• Race all 5 horses in each group, keeping track of the top 3 fastest horses in each race.

• After 5 races, you will have the top 3 fastest horses from each group.

• Race the top 3 horses from each group in a final race to determine the overall top 3 fastest horses.

OOP is a programming paradigm based on the concept of objects, which can contain data in the form of fields and code in the form of procedures.

• OOP focuses on creating objects that interact with each other to solve problems.

• Key concepts include encapsulation, inheritance, and polymorphism.

• Encapsulation involves bundling data and methods that operate on the data into a single unit.

• Inheritance allows a class to inherit properties and behavior from another class.

• Polymorphism allo...read more

Find repeating numbers in an array of n elements containing numbers from 0 to n-1 in O(n) time and constant memory space.

• Create an empty result array.

• Iterate through the array and for each element, take its absolute value and subtract 1 from it.

• If the element at the new index is positive, make it negative.

• If it is already negative, add the original element to the result array.

• Return the result array.

Fail-fast iterators throw ConcurrentModificationException if the collection is modified while iterating. Fail-safe iterators do not throw exceptions and operate on a cloned copy of the collection.

• Fail-fast iterators throw ConcurrentModificationException if the collection is modified while iterating.

• Fail-safe iterators do not throw exceptions and operate on a cloned copy of the collection.

• Fail-fast iterators are used in most of the Collection classes like ArrayList, HashMap, e...read more

Different ways to traverse over a map in Java include using keySet(), entrySet(), and forEach() method.

• Use keySet() method to iterate over keys in the map

• Use entrySet() method to iterate over key-value pairs in the map

• Use forEach() method to iterate over key-value pairs in the map

Program to calculate total number of valid words possible from a given word and dictionary

• Create a hash table of dictionary words

• Generate all possible permutations of the given word

• Check if each permutation is a valid word in the hash table

• Return the count of valid words

Memory management in operating systems involves allocation, deallocation, and optimization of memory usage.

• Memory management is crucial for efficient utilization of system resources.

• Operating systems use techniques like paging, segmentation, and virtual memory to manage memory.

• Memory management also involves handling memory leaks, fragmentation, and ensuring data integrity.

• Examples include malloc() and free() functions in C programming for dynamic memory allocation.

The Lowest Common Ancestor (LCA) of two nodes in a binary tree is the deepest node that is a common ancestor of both nodes.

• Start from the root node and traverse the tree to find the given nodes.

• Store the paths from the root to each node.

• Compare the paths to find the last common node, which is the LCA.

HashMap in Java is a data structure that stores key-value pairs and uses hashing to efficiently retrieve values.

• HashMap uses an array of buckets to store key-value pairs.

• The key is hashed to determine the index in the array where the value will be stored.

• In case of hash collisions, a linked list or a balanced tree is used to store multiple values at the same index.

• HashMap allows null keys and values.

• Example: HashMap<String, Integer> map = new HashMap<>(); map.put("key1", 1);

Definite integral of a function within given limits a to b.

• Use the definite integral formula: ∫[a, b] f(x) dx = F(b) - F(a), where F(x) is the antiderivative of f(x).

• Calculate the antiderivative of the function and then evaluate it at the upper and lower limits.

• Make sure to check for any discontinuities or singularities within the interval.

• Example: Calculate ∫[0, 2] x^2 dx = (1/3)x^3 |[0, 2] = (1/3)(2^3) - (1/3)(0^3) = 8/3.

Find the point closest to a given point P among a million points.

• Preprocess the million points to calculate their distances from P.

• Store the distances and corresponding points in a data structure.

• Sort the distances in ascending order.

• Return the point corresponding to the smallest distance.

I chose the technologies based on their compatibility with the project requirements and my familiarity with them.

• Chose React for front-end development due to its component-based architecture and ease of use

• Used Node.js for back-end development because of its non-blocking I/O and scalability

• Selected MongoDB as the database for its flexibility with unstructured data and ease of integration

The virtual keyword in C++ is used to declare a member function in a base class that can be overridden in derived classes.

• Virtual functions allow for dynamic polymorphism in C++ by enabling late binding.

• Virtual functions are declared in the base class with the 'virtual' keyword and can be overridden in derived classes.

• When a derived class overrides a virtual function, the function in the derived class is called instead of the base class function.

• Virtual functions are typicall...read more

C is a procedural language, C++ is an object-oriented language, and Java is a platform-independent language.

• C is a procedural programming language, while C++ supports both procedural and object-oriented programming.

• C++ is an extension of C with additional features like classes and inheritance.

• Java is a platform-independent language that runs on a virtual machine and uses automatic memory management.

• C is closer to the hardware and is used for system programming, while Java is ...read more

Collection Hierarchy in Java represents the relationship between various collection interfaces and classes.

• Collection interface is the root interface in the Collection Hierarchy.

• List and Set interfaces extend the Collection interface.

• Map interface is not a subtype of Collection interface.

• ArrayList, LinkedList, HashSet, and TreeSet are some of the classes that implement the Collection interfaces.

• HashMap and TreeMap are classes that implement the Map interface.

The virtual keyword is used in C++ for creating virtual functions and implementing polymorphism.

• Used to create virtual functions that can be overridden by derived classes

• Allows for dynamic binding of functions at runtime

• Used in implementing polymorphism

• Can be used with multiple inheritance to resolve ambiguity

• Example: virtual void functionName() = 0; creates a pure virtual function

Fragmentation in operating systems is the phenomenon where memory or disk space is divided into small chunks over time, leading to inefficient use of resources.

• Fragmentation can occur in both memory (memory fragmentation) and disk space (disk fragmentation).

• External fragmentation happens when free memory or disk space is broken into small pieces, making it difficult to allocate large contiguous blocks of memory or disk space.

• Internal fragmentation occurs when allocated memory...read more

I am interested in working with web apps.

• Web apps have a wider reach and are more accessible.

• They can be accessed from anywhere with an internet connection.

• Web apps are easier to update and maintain.

• Examples: Facebook, Google Docs, Amazon

AtomicInteger is a class in Java that provides atomic operations on integers.

• It is used for operations that need to be performed atomically, without interference from other threads.

• Common methods include get(), set(), incrementAndGet(), decrementAndGet(), etc.

• Example: AtomicInteger count = new AtomicInteger(0); count.incrementAndGet();

Program to find GCD of a set of numbers using Euclid's algorithm.

• Take two numbers and find their GCD using Euclid's algorithm.

• Repeat the process for all numbers in the set.

• The final GCD will be the GCD of the entire set.

• Use recursion to simplify the code.

• If any number is 0, return the other number as GCD.

The puzzle involves finding the fastest 3 horses out of 25, using only 5 lanes for races.

• Divide the horses into groups of 5 and race them, identifying the fastest horse in each group.

• Race the fastest horses from each group to identify the overall fastest horse.

• Race the second fastest horse from each group to identify the second fastest overall horse.

• Race the third fastest horse from each group against the two remaining untested horses to identify the third fastest overall hor...read more

IAAS, PAAS, and SAAS are different cloud computing models that offer varying levels of control and management to users.

• IAAS (Infrastructure as a Service) provides users with access to virtualized computing resources such as servers, storage, and networking. Users have complete control over the infrastructure and are responsible for managing it.

• PAAS (Platform as a Service) provides users with a platform to develop, run, and manage applications without having to worry about the...read more

Polymorphism is the ability of an object to take on many forms. Other OOPS concepts include inheritance, encapsulation, and abstraction.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• Inheritance allows a class to inherit properties and methods from another class.

• Encapsulation is the bundling of data and methods within a class, hiding the internal details.

• Abstraction focuses on providing only essential information to the outsid...read more

To measure and ensure not breaching SLA, track performance metrics, set alerts, prioritize tasks, and regularly review and adjust processes.

• Track performance metrics such as response time, uptime, and error rates

• Set up alerts for when performance metrics approach SLA thresholds

• Prioritize tasks based on their impact on SLA compliance

• Regularly review and adjust processes to optimize performance and prevent breaches

Implement automated monitoring and logging to proactively detect errors before customers report them.

• Set up automated monitoring tools to track system performance and detect anomalies

• Implement logging mechanisms to capture errors and exceptions in real-time

• Utilize error tracking software to aggregate and analyze error data

• Establish alerts and notifications for critical errors to prompt immediate action

• Regularly review error logs and performance metrics to identify patterns an...read more

Dynamic programming solution to find minimum cost of painting houses with no adjacent houses of same color

• Create a 2D dp array to store the minimum cost of painting each house with each color

• Iterate through each house and each color option, updating the dp array with the minimum cost

• Return the minimum cost of painting the last house

Program to delete a node in a singly linked list given only a pointer to the node to be deleted

• Copy the data from the next node to the current node and delete the next node

• Update the pointer of the current node to point to the next node's next node

• Handle edge cases where the node to be deleted is the last node in the list

Design optimal data structures for LRU cache

• Use a doubly linked list to keep track of recently used items

• Use a hash table to store key-value pairs for quick access

• When an item is accessed, move it to the front of the linked list

• When the cache is full, remove the least recently used item from the back of the linked list and hash table

To build low latency systems, focus on optimizing code, reducing network latency, using efficient data structures, and leveraging caching.

• Optimize code by reducing unnecessary computations and improving algorithms

• Reduce network latency by minimizing round trips and using efficient protocols like UDP

• Use efficient data structures like arrays and hash maps for quick access to data

• Leverage caching to store frequently accessed data in memory for faster retrieval

Program to insert an element into a sorted linked list

• Traverse the linked list until the correct position is found

• Create a new node with the element to be inserted

• Adjust the pointers of the previous and next nodes to point to the new node

• Handle edge cases such as inserting at the beginning or end of the list

Intuit is a financial software company known for products like QuickBooks and TurboTax.

• Intuit is a leading provider of financial software solutions for individuals and businesses.

• They are known for products like QuickBooks, TurboTax, and Mint.

• Intuit's software helps users manage their finances, taxes, and accounting efficiently.

• The company focuses on simplifying financial tasks for users through user-friendly interfaces and automation.

• Intuit has a strong reputation for custom...read more

Design a bus seat booking system.

• Use a database to store seat availability and bookings

• Implement a user interface for customers to select and book seats

• Consider implementing a payment system for reservations

• Allow for seat selection based on preferences such as window or aisle

Check if a string of parenthesis is valid or not.

• Use a stack to keep track of opening parenthesis.

• Iterate through the string and push opening parenthesis onto the stack.

• When encountering a closing parenthesis, pop from the stack and check if it matches the corresponding opening parenthesis.

• If stack is empty at the end and all parenthesis have been matched, the string is valid.

I have worked on AWS technologies such as EC2, S3, Lambda, and RDS.

• EC2 (Elastic Compute Cloud)

• S3 (Simple Storage Service)

• Lambda

• RDS (Relational Database Service)

C is a procedural language, C++ is an object-oriented language, and Java is a class-based object-oriented language.

• C is a low-level language used for system programming and embedded systems.

• C++ is an extension of C with added features like classes, inheritance, and polymorphism.

• Java is platform-independent and has automatic memory management through garbage collection.

• Java programs run on a virtual machine, while C and C++ programs compile to machine code.

• C++ is often used fo...read more

Web 2.0 is more interactive and user-generated content-driven, while Web 1.0 was static and read-only.

• Web 2.0 allows for social networking and collaboration, while Web 1.0 was primarily informational.

• Web 2.0 relies on user-generated content, while Web 1.0 was created by developers and publishers.

• Web 2.0 is more dynamic and responsive, while Web 1.0 was static and slow to load.

• Examples of Web 2.0 sites include Facebook, Twitter, and Wikipedia, while Web 1.0 sites include early...read more

Success metric is a quantifiable measure used to determine the effectiveness of a product or project.

• Success metric should be aligned with the overall goals and objectives of the product or project.

• It should be specific, measurable, achievable, relevant, and time-bound (SMART).

• Examples of success metrics include revenue growth, customer satisfaction scores, user engagement metrics, and market share.

• Regularly tracking and analyzing the success metrics can help in making data-d...read more

I have prepared over 100 tax returns for individuals and small businesses.

• I have experience preparing both individual and small business tax returns

• I am familiar with various tax forms such as 1040, Schedule C, and Schedule E

• I have worked with clients to maximize deductions and credits

• I have experience with tax software such as TurboTax and TaxAct

Agile working methods involve iterative development, collaboration, flexibility, and continuous improvement.

• Agile methods prioritize customer satisfaction through early and continuous delivery of valuable software.

• Teams work in short iterations called sprints, focusing on delivering working software frequently.

• Collaboration between team members, stakeholders, and customers is essential for success.

• Flexibility to adapt to changing requirements and feedback is a key principle o...read more

Design an event driven scheduler for managing tasks and events.

• Use a message queue system to handle incoming events and tasks.

• Implement event listeners to trigger actions based on specific events.

• Utilize a scheduling algorithm to prioritize and manage tasks.

• Include error handling mechanisms to handle failures gracefully.

LRU cache is a data structure that stores the most recently used items, discarding the least recently used items when full.

• Use a doubly linked list to keep track of the order of items based on their usage.

• Use a hash map to quickly access items in the cache.

• When a new item is accessed, move it to the front of the linked list. If the cache is full, remove the item at the end of the list.

Minimum platforms required to avoid train collisions

• Calculate the number of trains arriving and departing at each time slot

• Find the maximum number of trains present at any given time

• The minimum platforms required will be the maximum number of trains present at any given time

Polymorphism is the ability of a function or method to behave differently based on the object it is acting upon.

• Polymorphism allows objects of different classes to be treated as objects of a common superclass.

• There are two types of polymorphism: compile-time (method overloading) and runtime (method overriding).

• Example: Inheritance allows a child class to override a method from its parent class, exhibiting polymorphic behavior.

Code for stack operations in C++ using array

• Declare an array to store stack elements

• Implement push operation to add elements to the top of the stack

• Implement pop operation to remove elements from the top of the stack

• Implement peek operation to view the top element without removing it

Designed a high-level architecture for a web-based project using microservices and RESTful APIs.

• Utilized microservices architecture to break down the project into smaller, independent services.

• Implemented RESTful APIs for communication between services.

• Used a service discovery mechanism like Eureka or Consul for dynamic service registration and discovery.

• Ensured scalability and fault tolerance by incorporating load balancing and circuit breaker patterns.

• Secured communication ...read more

Convert integer to Roman numeral

• Create a mapping of integer values to Roman numeral symbols

• Iterate through the mapping to find the largest Roman numeral that fits the integer

• Subtract the value of the Roman numeral from the integer and repeat until the integer becomes 0

Normalization is the process of organizing data in a database to reduce redundancy and improve data integrity.

• Normalization involves breaking down a table into smaller tables and establishing relationships between them.

• There are different levels of normalization, with each level addressing a specific type of data redundancy.

• Normalization helps to prevent data inconsistencies and anomalies, and improves database performance.

• Example: A customer table can be normalized into a cu...read more

A valid binary search tree is a binary tree where the left subtree of a node contains only nodes with keys less than the node's key, and the right subtree only nodes with keys greater than the node's key.

• Nodes in the left subtree of a node must have keys less than the node's key.

• Nodes in the right subtree of a node must have keys greater than the node's key.

• In-order traversal of the tree should result in a sorted list of keys.

ITIL stands for Information Technology Infrastructure Library, a set of best practices for IT service management.

• ITIL provides a framework for organizations to plan, deliver, and support IT services.

• It consists of five core publications covering different aspects of IT service management.

• ITIL processes include incident management, problem management, change management, and more.

• ITIL helps organizations improve efficiency, reduce costs, and enhance customer satisfaction.

• Certif...read more

Design a system to match users with the nearest available driver like Uber.

• Use geolocation data from both users and drivers to calculate distances.

• Implement a matching algorithm to pair users with the nearest available driver.

• Consider factors like traffic conditions, driver availability, and user preferences.

• Utilize real-time updates to continuously update driver availability and user locations.