On my phone screen, everything seemed usual.

I initially answered the question using a LinkedList approach. The interviewer said it worked but noted that LinkedLists use extra memory for pointers. Therefore, I revised my logic to use an array with a circular queue mechanism. The interviewer seemed pleased (I assumed incorrectly).

Two days after the phone screen, I received the dreaded email.

This was my second phone screen at Facebook in two years. One thing is for sure: you need to give the best solution in one shot, with no going back and forth. They hire bots who know 1000+ questions on their fingertips from LeetCode, TopCoder, etc.

Moving average