So there was one single 1hour coding interview for final round, no other system design or anything.

I got 2 problems:
(1) https://leetcode.com/problems/k-closest-points-to-origin/
(2) https://leetcode.com/problems/serialize-and-deserialize-binary-tree/

For the first problem, I explained how binary search solution works and its time complexity, but had to abandon it because I verified that node values are given as float values in the interview (binary search solution could be used only when node values are integer). So interviewer said 'let's just go for O(nlogn) solution.' so I quickly implemented brute-force O(nlogn) solution. Interviewer said 'ok' and didn't ask about better solution (maybe using heap or quickselect), and just gave me second problem.
As for the second problem, I described how preorder-traversal solution works and implemented serialize/deserialize functions correctly in time. I explained why time complexity is O(n) and interviewer agreed. Time was up at this moment so we stopped coding interview, and moved on to general questions.
5 minutes were left for general questions, but our conversations lasted 15 minutes longer than expected. We talked about culture in the company and what I'd be doing at the first day if I get offer.

Would this be accept or reject if you were interviewer? (Or is it hard to decide?) I didn't do best at medium problem but did well in hard problem, so I really don't know how the result is going to be.

Any comments or questions are really appreciated!