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Topic: say I flip a coin 100 times...
Replies: 46   Last Post: Apr 18, 2005 9:42 PM

 Messages: [ Previous | Next ]
 tchow@lsa.umich.edu Posts: 1,133 Registered: 12/6/04
Re: say I flip a coin 100 times...
Posted: Apr 15, 2005 9:40 AM

HERC777 <herc777@hotmail.com> wrote:
<At time 0 there are 0 people flipping coins.
<At time 1/2 there is 1 person flipping coins at t=1/2, t=3/4, t=7/8...
<At time 3/4 there is another person flipping coins at t=3/4, t=7/8,
<t=15/16..
<At time 7/8 another person joins in flipping coins...
<and so on...
<
<At time t = 1, Herc starts flipping coins at t=1, t=2, t=3, t=4, t=5...
<
<How long does Herc flip out for until it is recognised he is unique
<from all of the masses?

Nice one! If we try to answer this in the same way as before, by defining
the answer to be the expected length of the longest prefix match, then we
find ourselves trying to evaluate (among other things)

(probability of a complete match) * (length of a complete match).

The probability of a complete match is zero, and the length of a complete
match is infinite. There isn't a good way of defining 0 * infinity, so the
expected value is undefined.
--
Tim Chow tchow-at-alum-dot-mit-dot-edu
The range of our projectiles---even ... the artillery---however great, will
never exceed four of those miles of which as many thousand separate us from
the center of the earth. ---Galileo, Dialogues Concerning Two New Sciences

Date Subject Author
4/12/05 HERC777
4/12/05 Jan Burse
4/12/05 HERC777
4/12/05 George Greene
4/13/05 Barb Knox
4/13/05 HERC777
4/13/05 Yajun
4/13/05 HERC777
4/13/05 Jay
4/13/05 HERC777
4/13/05 Jay
4/14/05 Yajun
4/14/05 George Greene
4/14/05 George Greene
4/13/05 Will Twentyman
4/13/05 briggs@encompasserve.org
4/13/05 briggs@encompasserve.org
4/14/05 George Greene
4/14/05 tchow@lsa.umich.edu
4/14/05 briggs@encompasserve.org
4/12/05 Tony
4/13/05 HERC777
4/13/05 ken quirici
4/13/05 Ralph Hartley
4/13/05 Robert Low
4/13/05 Ralph Hartley
4/13/05 Robert Low
4/13/05 tchow@lsa.umich.edu
4/13/05 HERC777
4/13/05 tchow@lsa.umich.edu
4/14/05 HERC777
4/14/05 George Greene
4/14/05 HERC777
4/15/05 tchow@lsa.umich.edu
4/15/05 tchow@lsa.umich.edu
4/16/05 George Greene
4/16/05 HERC777
4/17/05 George Greene
4/17/05 Patricia Shanahan
4/17/05 HERC777
4/18/05 Patricia Shanahan
4/17/05 tchow@lsa.umich.edu
4/18/05 HERC777
4/18/05 George Greene
4/18/05 tchow@lsa.umich.edu
4/18/05 HERC777