The problem is not only suited to Lisp because of the reason Anonymonk gave, but also because the most elegant solution to this problem is one that requires more exposure to CS than most Java programmers (in my experience) tend to have. I just coded up something similar in JS for a Go-playing program I'm playing with (thanks to tye's NextPermute() implementation in Algorithm::Loops). I have no desire to actually write it, so I'll give my plan in readmore tags below.
in reply to One for the weekend: challenge
The problem is really a graph-walking problem. Each letter corresponds to a set of vertices. The phone number creates a graph between each set of letters along with the punctuation. Once the graph is created, you walk all the various end-to-end paths (using NextPermute(), for example) and compare the resulting string with the dictionary. Shouldn't take more than 100 lines.
My criteria for good software:
- Does it work?
- Can someone else come in, make a change, and be reasonably certain no bugs were introduced?