[sbov]

Problem 2 is underspecified so both answers might be wrong. Should the output on the string "aaaabbbaa" be "a4b3a2" or "a6b3"? Or is that invalid input? I don't think you can reasonably answer the problem without an example like this.

[rootlocus]

He mentions he was asked to write the answer during an interview, so it's possible the problem was underspecified intentionally to test how the candidate explores the input space.