Microsoft Software Development Engineer interview questions

Microsoft showed up at our campus' career fair. I dropped my resume by their booth and a few weeks later was notified via email that I was invited to an interview on my college's campus. The interview was 30 minutes long and consisted of about 15 minutes of behavioral questions and the other 15 minutes was for the one technical question listed below. The behavior questions included things such as "Why did you choose computer science?"

There is only one question, find the common ending sub string from a list of strings