I was contacted by a LinkedIn recruiter who was very responsive over email.

I then had a phone screen with an engineer. The phone screen did exactly what a phone screen should: it verified my resume. The interviewer had me do some basic coding over CollabNet and was very helpful in answering my questions about the company.

Having passed the phone screen, I went in for an in-person interview. It was an all-day affair; I arrived at 10:00 AM and left around 5:30 PM. The day consisted of a series of 45-minute interviews with pairs of engineers and managers from various groups within the department for which I was interviewing.

They have a well-oiled interview process. When I arrived, they presented me with a loaner iPad containing my interview schedule. They also gave me a tour of the campus, and when I reached the interview room, there were several gifts waiting for me.

Unlike companies such as Google, the interview questions were aimed at assessing my skills rather than establishing the interviewer's "alpha-geek" status. Many questions were challenging without being "gotcha" questions. They were the sort of questions that an experienced engineer should be able to answer.

Consider an X x Y array of 1's and 0's. The X axis represents "influences," meaning that X influences Y. So, for example, if array[3,7] is 1, that means that 3 influences 7.

An "influencer" is someone who influences every other person, but is not influenced by any other member.

Given such an array, write a function to determine whether or not an "influencer" exists in the array.