eSmart Tech Embedded Software Engineer interview questions

I had a Phone Screen with easy coding problems. Next was On-site. I drove down to San-Diego for 2 hours. CEO appeared for the interview and he wasn't welcoming at all. After a cold brief introduction of himself, we moved onto solving a design problem. I was just graduated from college in CPE at that time, and didn't have any professional experience. I struggled and asked him for hints. He said that I should've learned this at college. Obviously, I never learned this at college, so I didn't know how to come up with the answer. He seemed very angry that I didn't know the answer to this simple(?) question, wasting his time. He started talking on the phone from there, ignoring me. It was a cold experience. I get that the CEO is an expert in his area, but he was arrogant and very rude, and I was able to foresee what it would be like to work for him. I was lucky that I didn't get the job. If I get a chance to interview at this company again, I wouldn't waste my time and I'll just move on. The CEO need to learn how to respect interviewees!