in reply to
One for the weekend: challenge
Pfah! Cannot they write problems like this without ambiguities? We hates them, we do.
The one that's bothering me is the "can" in: "If and only if at a particular point no word at all from
the dictionary can be inserted,". Does that mean "can be inserted to successfully produce a
solution"? Or "can be inserted whether or not a correct solution results"? If the former,
given the single-word dictionary "aaa", "55555" has solution "5 aaa 5". If the latter, it has