A recruiter contacted me through a professional social network. After a brief phone screen, the recruiter sent me some information on the interview process and offered to set up a technical phone interview with a Google engineer. A few weeks later, I set up the interview. Roughly a week after the interview, I received a response from the recruiter stating they did not wish to move forward.

Given a string of symbols with no delimiters between letters, and a lookup table to translate symbol sequences into letters, write code to determine all possible interpretations of the string.