Title: Microsoft Interview Problem

Solve it in 10 min!!!

An actual subject: MS Interview problem
This question is asked at Microsoft job interviews.  The interviewer said 
it should take you 10 min max. 
There are 4 men who want to cross a bridge.  They all begin on the same 
side.  You have 17 minutes to get all of them across to the other side.  It 
is night.  There is one flashlight.  A maximum of two people can cross at 
one time.  Any party who crosses, either 1 or 2 people, must have the 
flashlight with them. The flashlight must be walked back and forth, it 
cannot be thrown etc. Each man walks at a different speed.  A pair must 
walk together at a rate of the slower man's pace.
Man 1: 1 minute to cross.
Man 2: 2 minutes to cross.
Man 3: 5 minutes to cross.
Man 4: 10 minutes to cross.
For example, if Man 1 and Man 4 walk across first, 10 minutes have elapsed 
when they get to the other side of the bridge.  If Man 4 returns with the 
flashlight, a total of 20 minutes have passed, and you have failed the 
mission.
See how quickly you can solve this! 
p.s. The flashlight cannot shine a long distance.  No one can be carried, 
etc.  (This is a straightforward problem.  There are no tricks.

 
<Wil's note... page down for my solution if you can't figure it
out....>

From: Hank








































The numbers represent the men with their respective required crossing
time.  SideX represents where the men are after each "move".

Side1 		Bridge			Side2			Time Elapsed
1,2,5,10
5,10			1,2->				1,2			2
2,5,10		<-2				1				+2 = 4
2				5,10->			1,5,10		+10 = 14
1,2			<-1				5,10			+1 = 15
				1,2->				1,2,5,10		+2 = 17