You are hot on the trail of an enemy, who is hiding in one of 17 caves.

The caves form a linear array, and every night your enemy moves from the cave he is in to one of the caves on either side of it.

You can search two caves each day, with no restrictions on your choice. For example, if you search (1, 2), (2, 3), ..., (16, 17), then you are certain to catch him, though it might take you 16 days.

What is the shortest time in which you can be guaranteed of catching your enemy?

(In reply to Better solution than The Solution by AvalonXQ)

Hi Avalon,

After many trials, and with the help of Brian, we came to the conclusion that you are quite right.

Brian will try to change the "official solution", linking to your comment with the solution. It seems that this is problematic.

Congratulations, since as you can see, everybody agreed with the 14-steps.

Just a curiosity: what made you think that the "solution", found by 3 or 4 members, could be improved?

Cheers. 

 

Posted by pcbouhid on 2008-12-26 12:33:30