I was recently interviewed at Google at one of its EU office. The interview was 45m long and the interviewer just copy and pasted the question. I was waiting for him to say something but later I had to figure out everything. The question was required to use some interface/API, meaning not your everyday matrix manipulation, so I had to ask few questions.

Problem:
https://leetcode.com/discuss/interview-question/1349302/Google-or-Phone-interview-or-Crossword-search (I was asked exactly this question for the interview)

Approach:
I solved the question with O(R x C) time complexity. I spent initial 20m asking questions related to the test cases, so that I am very confident when writing the code. He ran his test cases and was happy with the code structure.

Result:
Rejected, due to asking many questions on input/output.

Preparation:
It took me almost 3 weeks for the preparation. I solved the blind 75 and almost 130 out of 150 Neetcode and 200+ LC questions. I will say Neetcode 150 is more than enough as it covers everything. The question as you can see is easy to medium level.

Thoughts:
Although, I was very confident that I will be interviewed onsite as I solved the problem and coded up in 5-7m but got heart broken after recruiter's feedback. I am not sure what else they are looking for, first they want you to ask questions then they reject you for that. Just FYI, I didn't asked questions like I wanted some hints. It was mostly, "If this is the input string, will it result like this?", "Can you please tell me what is the expected output of this interface" etc.