Meta Intern Software Engineer interview questions

On my technical interview I was asked questions about time and space complexity, and to implement some simple algorithms. Example - check if string is a palindrome.

The technical question itself wasn't hard. I thought I did okay but I have no idea what the interviewer was thinking or even saw what I was doing since he was on his phone the whole time. Overall, not as hard as I excepted but the whole thing just felt very unprofessional. It seemed like he already made up his mind about me after the first 10 minutes then moved on.