A more generalized version of the problem was posted as a practice question in Google's codejam contest: http://code.google.com/codejam/contest/32003/dashboard

A more generalized version of the problem was posted as a practice question in Google's codejam contest: http://code.google.com/codejam/contest/32003/dashboard#s=p2 http://code.google.com/codejam/contest/32003/dashboard#s=p2 I suggest solving this version of the problem, as it forces you to look at the problem from various perspectives. If you're stuck you can download solutions from the dashboard (link in top right corner).