The questions were difficult but they were not looking for absolute answers , they focused on the approach, and once you have an algorithm for the problem You need to code it and explain. So, it was kind of tough but they were supportive. And its not that you need to get your answers correct but you need to think out of the box. there were 2 questions in each round ,and each round lasted for about an our. from personal experience I can say, don't give up just becoz it looks difficult, becoz I got almost no answer correctly But still I got selected for the fourth round. "The bar raiser round".... 6 out of 29 people made it to the fourth round, which will be scheduled some day in the next 2 weeks. they said we wil either have a job or at least the internship.

Number of Islands — given a 2D grid of '1's (land) and '0's (water), count the number of connected islands. Walk through DFS vs BFS, and discuss how to avoid revisiting cells (in-place mutation vs visited set) and what changes if the grid is huge and must stream from disk.