The question was explain the exact approach Java uses to hash strings, not come up with a way to hash string or explain why does this particular approach work for hashing strings.
Much like hashes themselves going one direction is much harder than the other.
Meanwhile, my actual Google interviewer asked me how I might do it. He then explained why my Gödel numbering scheme was bad, showed me how Java does it, was seemingly satisfied enough and offered me a job on his team.
Google has a bad rep, but it is possible to sort it out.
Much like hashes themselves going one direction is much harder than the other.