R Systems Automation Tester interview questions

online test had questions from java, selenium, javascript, assertions, etc. I was able to clear the online test easily. The technical interview was with an interviewer who had same experience as that of mine. He joined the interview 10mins late, then he asked me vague questions and even though I answered those with most accurate answers, he behaved as if I should have answered better. Then he asked me to write a java code, I was able to get that done, the moment I was about to finish writing my code, he started rushing things, he was like you didn't even need this approach. In short, he intentionally wasted my time by asking vague questions and didn't let me finish coding so that he could reject me. This happens many times, when people see you as competition. Interviewers like these waste time and energy of candidates and the company. Questions asked: 1. Difference between noSuchElementException, StaleElementReferenceException 2.How would you validate a web app which has 10000 data points varying every 3 seconds. He was just so unclear with his question every time he changed the requirement. 3. Write a java code to find duplicate string count and unique string count from this given example: abc, abc, pqr, mno, pqr, xyz, pqr, jhl