A Facebook HR recruiter contacted me directly through Facebook, asking if I was interested in an interview.

The process consisted of a phone interview and an onsite interview.

The phone interview involved questions about my background and experience. The onsite interview was a 30-minute, intense, real coding session on a whiteboard. Two questions were given during the onsite interview:

1. Reversing a linked list.
2. Writing a regular expression parser.

However, as only 30 minutes were allocated for coding both questions, I was unable to finish them. I completed the first question and was halfway through the second. I never received a reply from them afterward.

Write the actual code to reverse a linked list.

Write the actual code to parse a regular expression including "*", which stands for 0 or more characters, "+", which stands for 1 or more characters, and ".", which stands for 1 exact character.