I am working on solving Shapeshifter -- I'm up to level 41 at the moment -- and though this is an old thread, I imagine other solvers will find it just as I did, on Google, and may be interested in my progress toward a solution. My solver uses a combination of Python and 'C', and I'm considering a wholesale shift to APL. My program solved level 40 in an even 1000 seconds. It solved level 31 (which the previous poster was stuck on) in a little over 4 seconds.
I am very interested in how far the original poster got with their program.
My page ->
http://shewhoshapes.wordpress.com
iLbi, my solver solved that board in 5.63 seconds. The (a) solution is:
(0, 3)
(2, 2)
(3, 1)
(1, 1)
(3, 3)
(2, 1)
(1, 2)
(0, 1)
(0, 1)
(1, 3)
(1, 0)
(0, 0)