UBS Software Engineer interview questions

Received an call from HR to schedule a programming exercise with a director of the team in the next few days. Then I attended the interview at the specified time and waited for an hour and thirty minutes and did not receive any call so I emailed the HR directly and then got a reply few hours later saying the interviewer did not feel well so asked to reschedule the meeting. I found this totally ridiculous of how they handle the incidents and just let the interviewee to wait for such long period of time without notifying the candidate ahead of time. The is absurd for such an large organisation and I feel the responsibility is on the interviewer too and I even suspect feeling unwell was simply an excuse. So I rescheduled the interview in the next day and finally received a call asked to implement a algorithm in Java which is not too difficult. I tried to explain my thought process and the steps I wanted to take before the implementation and seems the interviewer did not agree and asked me to do it directly which I found to be impolite and different from other interviews I had. Then asked me a couple of questions about TDD and asked to write test cases and finally finished the exercise. At the end of interview was the usual Q&A section and I sensed the interviewer just wanted to leave without taking my questions seriously. Negative experience about the interview organised by the interviewer and HR.