I applied online and was contacted by HR. A phone screen interview was scheduled for the following week.

The interviewer was kind. He told me about the role and asked me questions about my previous experience, some Linux commands on topics I am familiar with, and two coding questions.

He also provided feedback, stating he was satisfied with my answers and particularly liked one of my solutions.

Unfortunately, two days later, I received a rejection notice, and HR informed me that they had hired someone else.

If I have to find all files which are similar in a directory, which command should I use?

Later, he asked how that command would internally work.

Given an array with each element repeated once except one, find that one and optimize the solution for both space and time.