Meta Software Engineer interview questions

The interview was the standard "Coding Gameshow" where you can win a job. The interviewer asked me two technical questions. I nailed the first one. The second one, I struggled for a 3-4 minutes (asking questions all along the way). I finally arrived at a linear solution to the problem. The interviewer was not familiar with my approach and told me I was wrong. I suggested it should work but then proceeded to work out the version of the solution he wanted. Unfortunately, I ran out of time. Interviewer was great to speak with, but ultimately was unfamiliar with all the solutions to the problem he asked.