Friday, January 12, 2007

Multi-tap mindwarp

I'm a latecomer to multifeatured cellphones and thus to text messaging on a keypad, but I wanted to pose a puzzle regarding the basic multiple-keypress text entry system. I'm referring to the system under which when you want to type the word "beer", you press '2' twice to get a 'b', then press '3' twice to get an 'e', then you have to pause or press the right arrow because next you need to press '3' twice again to get another 'e', and so on. In all, "beer" is keyed in via 2233~pause~33777.

Under this system, blessed are the words with lots of one-press letters such as "data", which you can bang out 3282. Four letters, four keypresses. But when the same one-press letter repeats consecutively, it's not as convenient because you either have to pause or press the right arrow. For example, "add", 23~pause~3. So my puzzle is: what is the longest english word which is entirely one-press letters and no pauses? The longest one I've been able to find is "pajama," a paltry six letters. Even so, I would be surprised to learn of a longer one.

I'd love to be able to coin a clever term for the class of words that "data" and "pajama" belong to, but the best I've come up with is unitap. Five-letter unitaps I've found include adapt, madam, and magma.

These puzzles occurred to me last night when I was visiting a hospital. There was a poster on the wall for the convenience of non-English speakers who require a translator. Point to your language and the staff will summon the proper translator for you; that was the gist of the poster. Anyway, the Tagalog entry read (in part) "Magpapatawag kami ng interpreter." I took out my phone and keyed that in gleefully. Magpapatawag! A twelve letter unitap!