Toast Inc Software Engineering interview questions

Interviewer didn't connect to the agreed call for 10 mins; I received an email saying there was a mixup and another person was going to interview me last minute. The interview lasted 15 mins less because of their interviewer mixup: the interviewer got kicked out of his meeting room before we could finish. There were also different interviewers for the exact same position, which was extremely strange as other successful candidates were asked how to check if a string is a palindrome while I was asked a graph traversal question, which took longer for me to code. Overall, they were very unprofessional and it was a waste of time as the last minute replacement interviewer didn't have enough time to properly conduct the interview and clearly was not on the same page with the other interviewers when it comes to the level of difficulty of the interview.