100+ Eviden Interview Questions and Answers

Given the head node of a singly linked list, return a pointer to the middle node. If there are an odd number of elements, return the middle element. If there are even elements, return the one farther from the head node.

• Traverse the linked list using two pointers, one moving one node at a time and the other moving two nodes at a time.

• When the fast pointer reaches the end of the list, the slow pointer will be at the middle node.

• If the number of elements is even, return the seco...read more

Find the most repeated number in an array of length n with numbers 1-n.

• Create a dictionary to store the count of each number in the array

• Iterate through the array and update the count in the dictionary

• Find the key with the highest count in the dictionary

The task is to find the Huffman codes for each alphabet in an encoded message based on their frequencies.

• The Huffman code is a binary string that uniquely represents each character in the message.

• The total number of bits used to represent the message should be minimized.

• If there are multiple valid Huffman codes, any of them can be printed.

• The input consists of multiple test cases, each with an array of frequencies.

• Implement the function to find the Huffman codes and return 1 ...read more

The question asks to find the total amount of rainwater that can be trapped in the given elevation map.

• Iterate through the array and find the maximum height on the left and right of each bar.

• Calculate the amount of water that can be trapped at each bar by subtracting its height from the minimum of the maximum heights on the left and right.

• Sum up the amount of water trapped at each bar to get the total amount of rainwater trapped.

The task is to find the minimum number of edges that need to be reversed in a directed graph to find the path from a start node to an end node.

• The problem can be solved using graph traversal algorithms like Breadth First Search (BFS) or Depth First Search (DFS).

• Start by creating an adjacency list representation of the directed graph.

• Perform a BFS or DFS from the start node to the end node, keeping track of the number of edges reversed.

• Return the minimum number of edges revers...read more

The task is to find all distinct triplets in an array that add up to a given sum.

• Iterate through the array and fix the first element of the triplet.

• Use two pointers approach to find the other two elements that sum up to the remaining target.

• Handle duplicates by skipping duplicate elements while iterating.

• Return the list of valid triplets.

Find the triplicate number in an array of duplicates.

• Iterate through the array and keep track of the frequency of each number.

• Return the number that appears three times.

• If no number appears three times, return null.

To launch custom made-to-order products, I would follow a process of market research, product design, and production planning.

• Conduct market research to identify customer needs and preferences

• Design products that meet those needs and preferences

• Develop a production plan that allows for customization without sacrificing efficiency

• Implement a system for taking and managing orders

• Ensure quality control throughout the production process

• Provide excellent customer service to ensure...read more

Reverse m nodes and leave n nodes in a linked list till the end.

• Traverse the linked list till m nodes and reverse them

• Traverse n nodes and continue reversing m nodes

• Repeat the above step till the end of the linked list

• Handle edge cases like m or n being greater than the length of the linked list

1) Check if existing file size is less than 10MB, append new data if yes, else create a new file. Output file to have one json per line.

• Check if file exists and its size

• If size is less than 10MB, append new data

• If size is greater than or equal to 10MB, create a new file

• Output file should have one JSON per line

Print only the leaf nodes of a doubly linked tree.

• Traverse the tree and check if a node has no children and both left and right pointers are null.

• If yes, then it is a leaf node and print it.

• If no, then continue traversing the tree.

• Use recursion to traverse the tree in a depth-first manner.

Session ID is stored in PHP as a cookie or a query parameter.

• Session ID can be stored as a cookie in the client's browser.

• Session ID can also be stored as a query parameter in the URL.

• The server identifies the client by retrieving the session ID from the cookie or query parameter.

• The session ID is then used to retrieve the corresponding session data stored on the server.

• The server can also use other methods like IP address or user agent to identify the client.

To attribute conversions, we can use various methods such as tracking pixels, unique URLs, and A/B testing. SEO improvements can be attributed through tracking changes in search engine rankings and organic traffic.

• Use tracking pixels to track conversions from specific sources

• Create unique URLs for different campaigns to track conversions

• Use A/B testing to compare the performance of different versions of a page

• Track changes in search engine rankings and organic traffic to attr...read more

Rearrange an array of positive and negative numbers with positive numbers on the left and negative numbers on the right.

• Create two empty arrays, one for positive numbers and one for negative numbers

• Loop through the original array and add positive numbers to the positive array and negative numbers to the negative array

• Concatenate the positive and negative arrays to create the rearranged array

To launch custom made-to-order products, focus on market research, production capabilities, and customer experience. Attribute conversions through tracking and analytics. SEO is crucial for online visibility.

• Conduct market research to identify demand and competition

• Assess production capabilities and logistics for customization

• Prioritize customer experience through seamless ordering and delivery

• Implement tracking and analytics to attribute conversions

• Optimize SEO strategies to...read more

The question asks to find two elements 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 as you iterate through the array for efficient lookup.

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

Change binary tree to make parent node the sum of root nodes

• Traverse the tree in post-order

• For each node, update its value to the sum of its children

• Return the updated root node

Yes

• Create an empty binary search tree (BST)

• Loop over the unsorted array

• For each element, insert it into the BST using the appropriate insertion logic

• Repeat until all elements are inserted

• The resulting BST will be built from the unsorted array

Create a pivot table and sort the data in ascending order.

• To create a pivot table, select the data range and go to the 'Insert' tab in Excel.

• Choose 'PivotTable' and select the location for the pivot table.

• Drag the desired fields to the 'Rows' and 'Values' areas.

• To sort the data in ascending order, click on the drop-down arrow next to the field name in the pivot table and select 'Sort A to Z'.

Explanation of search algorithms with their space and time complexities.

• Linear Search - O(n) time complexity, O(1) space complexity

• Binary Search - O(log n) time complexity, O(1) space complexity

• Jump Search - O(√n) time complexity, O(1) space complexity

• Interpolation Search - O(log log n) time complexity, O(1) space complexity

• Exponential Search - O(log n) time complexity, O(1) space complexity

• Fibonacci Search - O(log n) time complexity, O(1) space complexity

Yes, I would still work if I won a 10 crore lottery.

• I am passionate about my work and find fulfillment in it.

• Money is not the sole motivator for me.

• I would use the lottery winnings to secure my future and pursue my dreams.

• Working provides a sense of purpose, personal growth, and social interaction.

• I enjoy the challenges and learning opportunities that come with my profession.

Inorder traversal of a tree without recursion

• Create an empty stack and initialize current node as root

• Push the current node to stack and set current = current.left until current is NULL

• If current is NULL and stack is not empty, pop the top item from stack, print it and set current = popped_item.right

• Repeat step 2 and 3 until stack is empty

Indexing in MySQL improves query performance. There are several types of indexing in MySQL.

• Indexes are used to quickly locate data without scanning the entire table.

• Types of indexing in MySQL include B-tree, hash, full-text, and spatial indexes.

• B-tree indexes are the most common and suitable for most use cases.

• Hash indexes are used for exact match lookups.

• Full-text indexes are used for searching text-based data efficiently.

• Spatial indexes are used for optimizing spatial queri...read more

GET is used to retrieve data from a server, while POST is used to send data to a server.

• GET requests are idempotent, meaning they can be repeated without changing the result

• POST requests are not idempotent and can have side effects on the server

• GET requests can be cached by the browser, while POST requests cannot

• GET requests have limitations on the amount of data that can be sent, while POST requests have no limitations

• GET requests should not be used for sensitive data, as th...read more

Process vs Thread differences and synchronization, deadlock examples

• Process is an instance of a program while thread is a subset of a process

• Processes are independent while threads share the same memory space

• Synchronization is used to coordinate access to shared resources

• Deadlock occurs when two or more threads are blocked waiting for each other to release resources

• Examples of synchronization include mutex, semaphore, and monitor

• Examples of deadlock include dining philosopher...read more

Using lookup with product-based data to find the needed data.

• Use a lookup function like VLOOKUP or INDEX/MATCH to search for the needed data

• Identify the key or unique identifier to match the data

• Specify the range or table where the data is located

• Retrieve the desired data based on the lookup value

Yes, triggers can be used with select statements in SQL.

• Triggers are database objects that are automatically executed in response to certain events, such as insert, update, or delete operations.

• While triggers are commonly used with insert, update, and delete statements, they can also be used with select statements.

• Using triggers with select statements allows you to perform additional actions or validations before or after the select operation.

• For example, you can use a trigge...read more

LRU page replacement algorithm is used to replace the least recently used page in memory with a new page.

• LRU stands for Least Recently Used

• It is a cache eviction algorithm

• It is used to manage memory in operating systems

• It works by keeping track of the pages that are used recently and the ones that are not

• When a new page is to be loaded into memory, the algorithm checks which page has not been used for the longest time and replaces it with the new page

To launch vernacular content on Myntra, we will translate product descriptions, user reviews, and customer support. Success will be measured through increased engagement and conversion rates. The right time to launch will be determined by market research and user demand.

• Translate product descriptions, user reviews, and customer support into vernacular languages

• Measure success through increased engagement and conversion rates

• Determine the right time to launch through market re...read more

Yes, a constructor can be declared as private.

• Declaring a constructor as private restricts its accessibility to only the class itself.

• This can be useful in scenarios where you want to control the creation of objects of that class.

• Private constructors are commonly used in singleton design pattern implementations.

• Example: private constructor in a singleton class:

• class Singleton { private Singleton() {} }

I handle conflict by actively listening, finding common ground, and facilitating open communication. I gain stakeholder buy-in through clear communication, addressing concerns, and demonstrating value. My change management process involves thorough planning, effective communication, and stakeholder involvement.

• Actively listen to all parties involved in the conflict to understand their perspectives.

• Find common ground and areas of agreement to build a foundation for resolution....read more

String pool is a cache of string literals in memory. Garbage collection frees up memory by removing unused objects.

• String pool is a part of heap memory where string literals are stored.

• Strings in the pool are shared among multiple objects to save memory.

• Garbage collection identifies and removes objects that are no longer in use.

• String pool can be accessed using the intern() method.

• String objects created using new keyword are not stored in the pool.

Use stack to keep track of indices of opening parentheses, update max length when closing parentheses found

• Use a stack to keep track of indices of opening parentheses

• When a closing parentheses is found, update max length by calculating the difference between current index and top of stack

• Handle edge cases like extra closing parentheses or unmatched opening parentheses

• Example: Input: "(()()", Output: 4 (for "()()")

A cookie in PHP is a small piece of data stored on the client's computer. It has a size limit and an expiry date.

• A cookie is used to store information on the client's computer for future use.

• In PHP, cookies are set using the setcookie() function.

• The size of a cookie is limited to 4KB.

• Cookies can have an expiry date, after which they are no longer valid.

• The expiry date can be set using the 'expires' parameter in the setcookie() function.

• If no expiry date is set, the cookie wil...read more

It is impossible to accurately estimate the number of women driving red cars in Bangalore without specific data.

• There is no specific data available on the number of women driving red cars in Bangalore.

• Estimating the number of women driving red cars in Bangalore would require access to vehicle registration data or a survey of car owners.

• Factors such as car ownership trends among women and the popularity of red cars would also impact the estimate.

Contractors at Myntra receive certain benefits, including an employee discount code.

• Contractors at Myntra receive certain benefits, such as access to the company's employee discount code.

• The employee discount code allows contractors to purchase Myntra products at a discounted rate.

• Other benefits for contractors may include flexible work hours and the opportunity to work on exciting projects.

• However, the specific benefits for contractors may vary depending on their role and co...read more

To cut a rod in such a way that each part is obtained every day and the whole rod is obtained in a week.

• Cut the rod into 7 equal parts.

• Each day, use one part of the rod.

• By the end of the week, all parts will be used and the whole rod will be obtained.

Find the longest palindromic substring in a given string.

• Use dynamic programming to check for palindromes within the string.

• Start by checking for palindromes of length 1 and 2, then expand to longer substrings.

• Keep track of the longest palindrome found so far.

Creating a roadmap involves identifying goals, prioritizing features, and aligning with stakeholders.

• Identify business goals and objectives

• Gather feedback from stakeholders and customers

• Prioritize features based on impact and effort

• Create a timeline and milestones

• Align roadmap with company strategy and resources

• Regularly review and adjust roadmap as needed

A startup is a newly established business that aims to solve a problem or meet a need using innovative technology.

• Startups are focused on growth and scalability.

• They often operate in a fast-paced and dynamic environment.

• Startups use various technologies depending on their industry and product.

• Common technologies used in startups include web and mobile development, cloud computing, data analytics, artificial intelligence, and blockchain.

• Examples of startup technologies include...read more

Developers write code to create software, while testers ensure the quality of the software by finding and reporting bugs.

• Developers write code, while testers test the code.

• Developers focus on creating software features, while testers focus on finding bugs and ensuring quality.

• Developers work on the implementation, while testers work on the validation.

• Developers are responsible for coding and debugging, while testers are responsible for testing and reporting issues.

• Developers ...read more

System, black box, and whitebox testing are different approaches to testing software.

• System testing is performed on the complete system to ensure that all components work together as expected.

• Black box testing focuses on testing the functionality of the software without considering its internal structure.

• Whitebox testing involves testing the internal structure and implementation of the software.

• System testing is performed by end-users or independent testers, while black box a...read more

Yes, a constructor can be private.

• A private constructor can only be accessed within the class itself.

• It is often used in singleton design pattern to restrict object creation.

• Private constructors are also useful for utility classes that only contain static methods.

Session in PHP is a way to store and retrieve data for a user across multiple requests.

• Sessions are used to maintain user-specific data on the server side.

• A session is created for each user and is identified by a unique session ID.

• Session data can be stored in server files or in a database.

• Session variables can be accessed and modified throughout the user's session.

• Sessions can be used to implement features like user authentication and shopping carts.

The output result number of rows depends on the type of join used.

• Inner join returns only the matching rows from both tables

• Left join returns all rows from the left table and matching rows from the right table

• Right join returns all rows from the right table and matching rows from the left table

• Full outer join returns all rows from both tables

• Cross join returns the Cartesian product of both tables

There are two types of triggers: DML triggers and DDL triggers.

• DML triggers are fired in response to DML (Data Manipulation Language) statements like INSERT, UPDATE, DELETE.

• DDL triggers are fired in response to DDL (Data Definition Language) statements like CREATE, ALTER, DROP.

• Examples: A DML trigger can be used to log changes made to a table, while a DDL trigger can be used to enforce certain rules when a table is altered.

I measured growth of categories by analyzing sales data, market trends, and customer feedback.

• Utilized sales data to track category performance over time

• Analyzed market trends to identify growth opportunities

• Collected and analyzed customer feedback to understand preferences and make adjustments

• Implemented marketing campaigns to drive category growth

• Monitored competitor activity to stay ahead in the market

To increase the profitability of a social commerce business, I would focus on optimizing marketing strategies, improving customer engagement, and enhancing the user experience.

• Implement targeted advertising campaigns to reach specific customer segments

• Utilize data analytics to track and analyze customer behavior for personalized marketing

• Enhance social media presence and engagement to drive traffic and conversions

• Optimize website and mobile app design for seamless user experi...read more

Inorder traversal is a way of visiting all nodes in a binary tree by visiting the left subtree, then the root, and then the right subtree.

• Start at the root node

• Traverse the left subtree recursively

• Visit the root node

• Traverse the right subtree recursively

• Repeat until all nodes have been visited

QA focuses on preventing defects, while QC focuses on identifying and fixing defects.

• QA stands for Quality Assurance and is a proactive process that focuses on preventing defects by establishing processes and standards.

• QC stands for Quality Control and is a reactive process that focuses on identifying and fixing defects through testing and inspection.

• QA involves activities like requirement analysis, test planning, and process improvement.

• QC involves activities like test execu...read more

To create an assortment mix for a new category launch, I would analyze market trends, customer preferences, competitor offerings, and budget constraints.

• Conduct market research to understand customer needs and preferences

• Analyze competitor assortments to identify gaps and opportunities

• Consider budget constraints and pricing strategies

• Collaborate with suppliers to source a variety of products that meet customer demands

• Create a balanced assortment mix with a range of products i...read more

PreOrder traversal without recursion is done using a stack to simulate the function call stack.

• Create an empty stack and push the root node onto it.

• While the stack is not empty, pop a node from the stack and process it.

• Push the right child of the popped node onto the stack if it exists.

• Push the left child of the popped node onto the stack if it exists.

Criteria for ordering inventory for a new item

• Consider demand forecast and market trends

• Evaluate production lead times and supplier reliability

• Assess storage and shelf life requirements

• Analyze cost and profit margins

• Review past sales data for similar items

I have used tools like Slack, Zoom, Trello, and Google Docs to manage a remote team effectively.

• Slack for communication and quick updates

• Zoom for virtual meetings and video calls

• Trello for task management and tracking progress

• Google Docs for collaborative document editing

Alpha testing is done by internal teams, while beta testing involves external users.

• Alpha testing is conducted by the development team or quality assurance team within the organization.

• It is performed in a controlled environment before the software is released to the public.

• Alpha testing helps identify bugs, usability issues, and performance problems.

• Beta testing involves external users who are not part of the development team.

• It is conducted in a real-world environment to ga...read more

A linked list can be implemented in a binary tree by using the left child as the next node and the right child as the previous node.

• Each node in the binary tree will have a left child pointer and a right child pointer.

• Traversal of the linked list can be done by following the left child pointers.

• Example: In a binary tree, the left child of a node can point to the next node in the linked list.

The question asks to output the number of rows based on joins.

• The number of rows in the output depends on the type of join used.

• Inner join only returns rows that have matching values in both tables.

• Left join returns all rows from the left table and matching rows from the right table.

• Right join returns all rows from the right table and matching rows from the left table.

• Full outer join returns all rows from both tables.

• Use COUNT() function to count the number of rows in the out...read more

I use Adobe Photoshop for editing.

• Adobe Photoshop is the industry standard software for photo editing.

• It offers a wide range of tools and features for editing and enhancing images.

• Some examples of editing tasks in Photoshop include retouching, color correction, and image manipulation.