The Lost Sheep Challenge

Sasha Pachev sasha at
Fri Sep 28 16:07:52 MDT 2007

A question was asked a friend of mine during his interview with
Microsoft. It is hard to believe that I would have a friend that would
even consider interviewing with Microsoft, or at least I would be
ashamed to admit it on this list, but well, I do :-)

I decided to port this problem to the New Testament theme, and also
make it more friendly for non-programmers. Anybody who knows how to
use a calculator should be comfortable with it. So here it is:

You have 100 sheep in a flock and they are all numbered. Each has an
identification tag with a number -  1 through 100. One of them is
lost. Other sheep are scattered over the pasture and cannot be
examined in sequential order of their numbers. Come up with a method
that would allow you to quickly identify the lost sheep. The use of a
simple arithmetical calculator is allowed. The use of a pen or any
other note-taking instrument is not (to disallow the trivial but
unscaleable roll-call method).

Sasha Pachev
AskSasha Linux Consulting

More information about the PLUG mailing list