In 1st interview I solved the questions based upon the hint given by the interviewer. In 2nd interview, I solved the question without any hint, but unable to optimize the space complexity which the interviewer asked repeatedly, also no hint given by the interviewer. In 3rd interview, I solved the question without any hint and interviewer was pretty impressed by the solution as it was fully optimized. In 4th Interview, simple situation based questions and also my past experiences and projects.