Thanks a lot to everyone who took part in our speed programming competition yesterday evening, sponsored by Red Gate. I was really surprised with the number of people who had a solution to all four problems! The winner was David Purser, who solved all four problems, solving question 3 in O(n) time, who gets the fabulous prize! Most people who solved question x gave the minimax style solution, however a special mention goes to Alex Best who came up with the max flow style solution although unfortunately didn't have time to implement it. All solutions emailed to me are uploaded here.
Thanks to everyone who took part!