In a top security prison, BigBang, there is a tradition that any inmate can obtain freedom by passing through a 100m-long corridor without being caught by a blind guard. The corridor has nine 10m-long perpendicular branches on one side at every 10m and is so narrow, that only one person can pass at a time.

The inmate and the guard start walking toward each other from the opposite ends of the corridor at the same time. The guard may decide to check any of the side branches. The only rule is that the inmate has to maintain the same speed as the guard's at every moment.

Is it possible to get lucky and escape from BigBang?

Prisoner _|_|_|_|_|_|_|_|_|_ Guard

Approach the blind guard until you are 10 metres away.  At that point, set your direction according to the direction taken by the guard.  If the guard comes toward you, back up in the same direction to maintain the 10 metre cushion.  At the instance the guard decides to go down one of the perpendicular branches, advance forward to pass the guard.  By the time the guard returns to the main corridor, you will be 10 metres beyond his position.

Posted by hoodat on 2007-02-06 15:11:46