[brudgers]

If the person flattens a list with the:

   Google
   Copy
   Paste

Algorithm, are they a programmer? Are they more or less of a programmer if instead they use racket or clojure's built-in =flatten=?

[mannykannot]

It is the cases of failure that are interesting and informative, and if the methods you mention are the only ways a person can solve the problem, that counts as a failure - as I mentioned, this is not actually about flattening lists.