I got a two-hour (two sessions, each session 45 mins)phone call interview from Google. The interviewers called me on the phone and showed me a whiteboard for the coding challenge. The first interviewer pasted the input example and provided the expected output. The second interviewer discussed my research for 10 mins and then gave me the system design coding problem without inputting any single word. I figured out the first-session problem(path label not shown in LT) and wrote out the program though it has some bugs. However, I totally messed up the second-session (circular array) as the interview just simply explained the question without details. This is a kind of trap as many of the questions asked in Google interviews are deliberately underspecified so that the engineers are looking to see how you engage with the problem.
The question is not challenging, which lies at medium levels. However, it is really challenging to write code on the whiteboard within less than 45 mins. Basically, you have 5 minutes to figure out the problem and 10 minutes to address the problem. You just have 30 mins to write a logical and well-structured program. The mistake I made is that I went back and forth to ask clarifying questions and get hints, this wastes my time. I received the rejection next day.