Flipkart

# Flipkart Interview Experience - Grid Hackathon I got the opportunity to directly interview for Flipkart through their Grid hackathon. The interviews were conducted offline in the placement office. ## Round 1 *Type:** Technical, DSA only (1 hr) The interviewer started the interview by introducing himself and then he asked me to introduce myself. After the introductions, he asked me how comfortable I am with DSA and then started off with the first question. **Array Pairing Problem:** Given an array of integers, make pairs such that the total sum is maximum. First, I had to find the number of such pairs, and then as a follow-up, I had to return the pairs. The question was presented in an overly complicated story-type format with a lot of extra information, so it took me some time to understand it and clarify with the interviewer. I first gave a two-pass O(n) approach and then optimized it to one-pass O(n). He then asked me to write the pseudocode on a piece of paper, which I did. The interviewer seemed satisfied. The interviewer then asked me what my favorite DSA topic was, to which I replied DP. He then proceeded to give me a graph question. **Course Schedule:** [LeetCode - Course Schedule](https://leetcode.com/problems/course-schedule/). I solved this question pretty quickly and gave him both the approaches - plain DFS and Kahn’s algorithm. *Follow-up:** Given the time taken to go from the classroom of one course to another (basically the edge weights), find the order of courses to take such that the total time is minimized. While thinking aloud, I mentioned Dijkstra’s algorithm, so he started questioning me on the internal workings of Dijkstra, its advantages, and disadvantages. He also questioned me on the workings of the Bellman-Ford algorithm and how it compares to Dijkstra. At this point, the interview had gone off on a tangent and it seemed like he forgot/ignored the follow-up question. I had mentioned that Dijkstra’s algorithm uses a priority queue, so he questioned me on the internal workings of binary heaps and how they are implemented, insertion and deletion in heaps, etc. ## Round 2 *Type:** Technical, DSA only (1 hr) The interview started off directly without any introductions. **Vertical Order Traversal:** [LeetCode - Vertical Order Traversal of a Binary Tree](https://leetcode.com/problems/vertical-order-traversal-of-a-binary-tree/) **Search 2D Matrix:** [LeetCode - Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/) I was able to solve both the questions and was asked to write the pseudocode on the whiteboard. For both the questions, I explained my intuition and thought process clearly and the interviewer seemed satisfied. ## Overall Experience The interviewers were young and seemed very chill. Also, effectively communicating your thought process and how you arrive at a solution is just as important as actually solving the problem.