Google Analyst interview questions

I was interviewed once about 6 months ago and made it to the final on-site round where I unfortunately got rejected. A few weeks ago, I was contacted by a google recruiter again and got set up with the hiring manager for an interview. I expect a decision to come along soon. Overall, the interview process is competitive and there is no time wasted on repeated questions. I assume all the interviewers take detailed notes on your answers and make sure not to go over the same things again. All of the questions are thoughtful and are directed towards finding your thought process and capabilities under pressure. Does anyone know if google skips certain interview rounds if you have already been through them before?

1. Explain and Write KnapSack Algo with Memorization 2. Given a undirected graph, clone it. Now if the undirected graph has the neighbors with the nodes as same data - how do you make sure you create the exact same branches and also how do you make sure you don't run into loops for the exact node. He gave a empty directed graph and asked me write code after that. 3. Given two Btrees. these trees "may" have right and left branches swapped. Now compare it.