SCHOOL OF COMPUTER SCIENCE

 Another Hat Problem

Our 2n hat wearing friends are once again standing in a circle so that everyone can see everybody else’s hat. At a certain moment in time each person must simultaneously shout “my hat is black” or “my hat is white”. The team wins a big prize if at least n of the people get the color of their hat right. Of course, if fewer than n get it right, the whole team is eliminated and this is painful. Can they guarantee to avoid being eliminated?

    Solution