OJ Board

Have no idea how to solve this problem. Any hints?

I think you can try implementing dancing links technique proposed by Knuth. Look at his paper:
http://www.google.com/url?q=http://www-cs-faculty.stanford.edu/~uno/papers/dancing-color.ps.gz&ei=a8u_SrD4CojS8AbenOS5AQ&sa=X&oi=spellmeleon_result&resnum=2&ct=result&usg=AFQjCNFdmx1RwjzHXqprQeg1RaBKlw6o4w ...

yes, it works on sample. thanks for a hint. I'll think of O(1) solution.

Trying to solve this problem using dp as follows:
d[n][m][pi][pj][player] - stores who is will win if we have field n x m, and the bad piece is at cell (pi,pj) and current turn to cut the cake is at the hensel (player = 0) and at gretel(player = 1). But I'm constantly getting WA. Could this approach ...

I got that this problem is solved using diophant's method. In case the given test case has a solution and after we get a general solution for x (number of left flips) and y (number of right flips), how shall we get the minimum one?