so, the light gets turned off 100 times in total. there are 100 different people counting. none ever reach 100 in their count.
Re:Puzzle: 100 Prisoners and a Light Bulb
by shayan on Wednesday November 14, 2007 @10:55AM
(#79750)
I was trying to eliminate the one counter to make it faster, but I see your point ...you just saved a bunch of lives, and got yourself an up vote!...I looked at the other possible solutions and they all seem to take a while, but I am planning a escape, are you in?
Everytime someone visits the room has to take the following two steps:
(1)actions:
- if it's their first time make sure the light is off (i.e. if off don't touch, if it was on, turn it off)
- if you have been there before make sure the light is on (i.e. if it was off turn it on, and if it was already on don't touch it)
(2)counting:
- if the light was off when you walked in then add one more to your count
- if it was on then don't count anything
this way everyone counts, we now have 100 counters. And whoever reaches hundred first (counting themselves in) should report it.
Note: the guy that went in on day one, should not count for the day before, but everyone else will count their day before if appropriate (based on the rules above).