Good Evening,
I started working on the 17x17 4-colouring challenge, and I ran into a bit of an I/O snag.
It was an enormous headache to detect the differences in very similar 289-char strings.
Eventually, it made more sense to associate a CRC-Digest with each colouring.
After learning from a handful of incomplete web pages, and performing several calculations by hand, I decided to put together a comprehensive treatment of the CRC check process.
Please take a look at this single web page, and let me know if I left out anything important.
http://www.pathcom.com/~vadco/crc.html
My conclusion was that those people who are familiar with the CRC procedure, treat it as self-evident, while the rest need to figure it out by doing all kinds of research until they agree.
All the very best,
JohnPaul Adamovsky