Thanks Andrew (Andrew Solomon <andrew@illywhacker.net>) for your
suggestions. I'll try those tonight when I get home from work.
Since you asked about what the puzzle actually is, the fellow who posted it
at rec.puzzles (Kevin Buzzard <buzzard@ic.PUZZLE.ac.ELZZUP.uk>) had found it
on his nokia cell phone. It is called "rotation" at Nokia's web site
http://www.nokia.com/games
I think this variant is level 5.
The puzzle is a 4x4 square of numbers. There are four operations, each of
which involves rotating the numbers in a 3x3 square clockwise. So, in the
diagram below, one move is the cycle (1,2,3,7,11,10,9,5). The numbers
maintain orientation-- they don't rotate; if they did, that would add
another layer of complexity for the solver.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Anyone who's interested in an archive of the discussion ofthis puzzle (it's
about a 40K byte text file), let me know. The discussion focuses primarily
on finding minimal move sequences to swap two given tiles.
There's a very well done java applet for a similar puzzle at
http://www.microprizes.com/mp52.htm
Bob