ByteDance Software Engineer (Backend) interview questions

After CV screening one online interview was scheduled on lark. Interviewer asked to sort numbers lexicographically. I approached with trie. But there is an optimized solution for this problem. That problem can be found in leetcode

1. HR invited me to an information call and asked about my available time slots. I gave them three time slots. But they finally chose a date which is not from the three time slots provided by me. If you already have the schedule, why do u ask me? 2. So I changed my schedule to fit their date. But they did not send me a confirmation email for the interview. 3. After a week's preparation, at the date they provided to me, HR gave me a call, and just told me they already found someone for this position. I feel tricked by this company's HR. They disrespect interviewers' time at all.