Energy Exemplar Interview Questions and Answers

Concatenate two LinkedList without using extra space in O(n) time

• Traverse the first LinkedList and update the last node's next pointer to the head of the second LinkedList

• Return the head of the first LinkedList as the concatenated LinkedList

Create a basic React app with dummy data fetched from a JSON API.

• Set up a new React project using create-react-app

• Create a component to fetch data from a JSON API using fetch or axios

• Display the fetched data in the component

MySQL query to select the id of second highest salary from employee table

• Use ORDER BY clause to sort salaries in descending order

• Use LIMIT to select the second row

• Use a subquery to avoid duplicates if multiple employees have the same salary

Detect a loop in a linked list by using Floyd's Cycle Detection Algorithm

• Use two pointers, slow and fast, to traverse the linked list

• If there is a loop, the fast pointer will eventually meet the slow pointer

• Initialize slow and fast pointers at the head of the linked list

• Move slow pointer by one step and fast pointer by two steps in each iteration

• If the fast pointer reaches the end of the list or meets the slow pointer, there is a loop

Find the unique element in an array of strings

• Iterate through the array and use a hashmap to store the frequency of each element

• After iterating, check the hashmap for elements with frequency 1 to find the unique element

I primarily used Confluence for documentation.

• Confluence is a web-based platform for creating and sharing documentation.

• It allows for easy collaboration among team members.

• I used Confluence to create user guides, API documentation, and release notes.

• The tool also offers version control and commenting features for feedback.

• I organized content using pages, spaces, and labels for easy navigation.

Active voice is when the subject of the sentence performs the action, while passive voice is when the subject receives the action.

• Active voice: The cat chased the mouse.

• Passive voice: The mouse was chased by the cat.

• Active voice is more direct and concise, while passive voice can be more formal or indirect.

• Active voice is generally preferred in technical writing for clarity and precision.