The process was very nice. I met with an engineer at my school's career fair and handed them my resume.

After two days, I received an email from a recruiter stating that they wanted to set me up with an interview on my campus. They also invited me to a dinner with the other students they had contacted, which was nice.

The interview at my school was a 45-minute session where they asked me one technical question. It went well, and the interviewer was very pleasant.

After that interview, I heard back within two days that they wanted to move forward. I was then able to schedule an interview on-site at their office in Menlo Park.

When the time came, they flew me out to Menlo Park for Facebook University Day. I had one 45-minute interview in the morning, followed by a full day of exploring what Facebook had to offer, including a tour of the office.

The on-site interview was the final stage of the process for interns. They sent me their final decision within a week.

Given an array of integers, determine if there are 3 numbers in the array that sum to zero. It is also valid to use one number in the array more than once; they don't all have to be unique. Time complexity is important.