luke_bkk saidOnly to discover C sucks. Due to the limits of the data structure I could only go to 17x17 grid. Still it runs like shit off a stick (1.5e-05s whatever that means). Any idea how you would deal with big numbers.
I'm using a 64 bit unsigned integer type for mine (if you're using gcc try uint64_t). You might be interested (or surprised?) to know that my C++ is basically the same line count as your Ruby — 15 lines.
