1st Online Phone screen interview: Given an array A of length N: A[0]..A[N-1]. Each element A[i] can only be a 0 or 1. If a sub-array only contains 0, we call it valid. How many valid sub-arrays are there in A? For example, A = [0, 0, 1, 0, 0, 0], there are 9 valid sub-arrays. 2nd Onsite interview: Q1. on data streaming of infinite users, and to find out top 5 most active users. Given a Whatsapp group, people are chatting, we have to find who uses the maximum number of words? Q2. on a robot finding a path in a grid from top-left to bottom right along the obstacles Given a grid of a terrain for a robot to traverse from one corner to opposite corner. find the path, or if even the path is possible. Grid is 10x10, or NxN. Given each square defines height or depth of the square. Q3. finding out the difference between two satellite images of same place 1 month apart Q4. on string and tree
