Game of Fifteen PSET3: CS50 - won function and check50

Hi I have yet another question about game of fifteen. I seem to have implemented by 'won' function correctly. Before this check50 was running and I was getting a pass for everything, excluding the 'won' function. Now I have implemented 'won' it even seems to work but now check50 is not passing the draw checks (something it previously passed) - can anyone help?

Code is here: http://ift.tt/2ehRHzB

Thanks