Why did the interviewer say no problem after the interview or didn't inform the admission?

First of all, it can be seen from your question that your interview is a dialogue interview, that is to say, there is no mathematical formula 1+ 1 =? So clear. Because the questions asked by the interviewer are answered according to your personal views and understanding, although the interviewer has a good evaluation of you, it does not rule out that it contains comfort elements for you, nor does it mean that you are 100% satisfied with your answers. If the interviewer meets another candidate who is similar to you or may be a little better than you, it will inevitably breed another tendency.

Secondly, even if the interviewer is satisfied with your answer, as an interviewer, he is only a recruiter, not a recruiter. That is to say, the interviewer should go back to the company and report the whole job interview to the boss, including your interview. After listening to the report, the boss can exercise the right to decide whether to hire or not.

Third, the whole interview process does have an element of "luck". In the game between candidates, luck is indeed a part of winning, but it does not rule out that this kind of "luck" still tends to come prepared.

Of course, this application doesn't give you information. You can make a plan to continue applying.