There was one round of phone screen and one round of on-site.

The phone interview lasted about 45 minutes, consisting of 10 minutes of resume questions and the remainder spent on two coding problems. The first question was quite easy, and the second was relatively hard (harder than the one I received during the on-site interview).

Unfortunately, I was not able to memorize the two problems from the phone screen. I do remember the question from the on-site interview (see the question part).

The whole process was excellent; Facebook did a great job treating interviewees from other states. The on-site question was not difficult, but perhaps because it was my first on-site interview, I was too nervous and made some mistakes.

The minimum distance of one designated point to another point from a set of points in a coordinate system.