HDTenEightyP/NetNews huggingface dataset:
From: ISW@cup.portal.com (Isaac S Wingfield)
Newsgroups: rec.puzzles
Subject: Re: Packing problem
Date: Fri,  9 Oct 92 08:20:51 PDT
Organization: The Portal System (TM)
  <1992Oct8.085724.10447@dcs.warwick.ac.uk>

In article <1992Oct6.020647.4651@ils.nwu.edu> blum@news.ils.nwu.edu 
(Daniel Blu
m) writes:
>A few years ago, this puzzle appeared in the newsletter of the company
>I was working for:
>
>   Given an infinitely long rectangular strip which is two units wide,
>and circles with diameters of one unit, one can pack them in parallel
>rows of two, like so:
>                      _____________________________
>                      |oooooooooooooooooooooooooooo...
>                      |oooooooooooooooooooooooooooo...
>                      -----------------------------
>However, there is a more efficient packing.  What is it?

If the strip is *infinitely long*, as stated, no alternate packing strategy 
is more efficient, in the sense that it would allow more circles to be fit 
into it...

Isaac   isw@cup.portal.com
From: rmurphy@aludra.usc.edu (Bob Murphy)
Newsgroups: rec.puzzles
Subject: Re: Cliff Puzzle 7: 3x3 recursion
Date: 16 Oct 1992 00:39:53 -0700
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: aludra.usc.edu

In article <1992Oct15.225047.18543@watson.ibm.com> cliff@watson.ibm.com (cliff) writes:

>Consider the 3x3 array below.  All nine digits are used exactly once.           
>1 9 2
>3 8 4
>5 7 6                                                                           
>Notice that "384" is twice the number in the first row, and that              
>"576" is three times the number in the first row.

>Questions:

>1.  Are there other ways of arranging the numbers to produce the same        
>result using each digit only once and the same rules?                         
>Remember, the second row must be twice the first.  The third row              
>must be 3 times the first row.                                       
                                                                               
By exhaustive search I found that there are only 4 starting numbers
which produce a 3x3 array with the desired property.  Here they are:

   1 9 2        2 1 9        2 7 3        3 2 7
   3 8 4        4 3 8        5 4 6        6 5 4
   5 7 6        6 5 7        8 1 9        9 8 1 


It was also asked whether one could take the last number in one of these
lists and begin a new array with it which also had the desired property.
The answer is clearly no since the above 4 are the only possible(i.e.
just note the last number in each of these arrays never begins one
of the other arrays.)


Bob Murphy (rmurphy@aludra.usc.edu)
From: ronnie@cisco.com (Ronnie B. Kon)
Newsgroups: rec.puzzles
Subject: Re: Dividing the plane
Date: 15 Oct 92 22:54:17 GMT
Organization: cisco Systems, Incorporated
NNTP-Posting-Host: lager.cisco.com

In article <1992Oct11.161305.1756@news.cs.indiana.edu>, "matthew drew" <mdrew@hammerhead.cs.indiana.edu> writes:
|> Thus spake 90tms@eng.cam.ac.uk (T.M. Speight)
|> >In article <1992Oct11.044715.14475@math.toronto.edu>hsieh@math.toronto.edu
|> >(Paul Hsieh) writes:
|> 
|> >   In article <1b36afINN8so@uwm.edu> radcliff@csd4.csd.uwm.edu 
|> >(David G Radcliffe) writes:
|> >   >First an easy one:
|> >   >
|> >   >Divide the plane into three disjoint subsets so that every line
|> >   >intersects exactly two of them.
|> 
|> >   Colour every point (0,x), x real and non zero, BLUE.  Colour (0,0) GREEN.
|> >   Colour the rest RED.
|> 
|> >No! A line parallel to the x-axis would then pass only through the red
|> >region.
|> 
|> >90tms@uk.ac.cam.eng      Cambridge University
|> >Toby Speight             Engineering Department
|> 
|> Change it to:
|>   Color (0,x) and (x,0), x real and nonzero, BLUE.
|>   Color (0,0) GREEN.
|>   Color the rest RED.
|> This fixes things nicely.

What about the line that runs from (1,0) to (2,0)?  It's only on RED.

-------------------------------------------------------------------------------
Ronnie B. Kon           | "Boy, they were big on crematoriums, weren't they?"
ronnie@cisco.com        |
(415) 688-4592          |           -- George Bush at Auschwitz, Sept 1989
-------------------------------------------------------------------------------
From: diamond@jit533.jit.dec.com (Norman Diamond)
Newsgroups: rec.puzzles
Subject: Re: Spaces in "C"
Date: 12 Oct 92 06:05:36 GMT
Reply-To: diamond@jit.dec.com (Norman Diamond)
Organization: Digital Equipment Corporation Japan , Tokyo

In article <10575@uqcspe.cs.uq.oz.au> warwick@cs.uq.oz.au writes:
>	1. Is it possible to translate ANY "C" program into an
>		equivalent one containing no whitespace?

If the program contains a space in a character or string constant, then
the final program also has to contain at least one space in some character
or string constant, unless you wish to depend on the character-set coding
(and no longer be strictly conforming nor maximally portable).

I think there might also be a problem with a declaration like
   volatile char x;
You can convert that to
   volatile char(x);
but you can't remove either word volatile or char without changing the
meaning.  But of course, if you were depending on x's volatility, then
your program was already non-strictly-conforming.

I guess the question needs to be tightened up a bit.  "ANY" C program means
any of "WHAT KIND" of C program?

>	2. What method will minimise the amount of overhead (or
>		maximise the underhead, if reducing spaces saves
>		characters)?

That would surely be undecideable.  If you constrain our memory size and
form of CPU, then it's decideable (though the machine that figures out the
answer will have to be much larger than the machine that these programs are
constrained to).  But when you ask only about programs without constraining
the machines, then most programs will be equivalent to some smaller programs
but it will be impossible to test which smaller programs are equivalent.
--
Norman Diamond       diamond@jit081.enet.dec.com
If this were the company's opinion, I wouldn't be allowed to post it.
"Yeah -- bad wiring.  That was probably it.  Very bad."
From: dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER)
Newsgroups: rec.puzzles
Subject: Re: TRAPPED BUBBLE (answer)
Date: 14 Oct 92 16:17:30 GMT
Organization: Lehigh University

In article <10002@ncrwat.Waterloo.NCR.COM>, tjgerman@53iss6.Waterloo.NCR.COM (Tr
evor German) writes:

>               Take a cylinder of _incompressible_ fluid. Attach a
>       balloon to the lid of the cylinder and seal the cylinder
>       with the lid such that there is no air trapped within.
>
>               Now flip the cylinder upside down.
>
>               The question is, what happens to the baloon. Does it
>       get bigger or smaller. What happens to the pressure in the
>       baloon, does it change. What are the thermal effects if any.
>
>               As a corolorary what would happen if the situation
>       was reversed and the baloon was stuck to the bottom before
>       the fluid was added, the tube sealed, and inverted.

The baloon, in both cases, should deform.  Though the liquid is incompressible,
it should provide a static pressure which is depth dependant (head).  The
volume of the baloon will not change, but it should in the first case, become
more elongated, and in the second case, become more squat.  The pressure in
the baloon should not change, but the zenith direction (vertical) stresses
in the baloon wall should increase in the first case and decrease in the
second.
The above analysis is based on the assumption that the baloon is filled
with a fluid of less density than the incompressible liquid in the container.
The thermal effects should be negligible unless either fluid involved is
extremely viscous and the process were executed with relative speed and/or
repeatedly.  Thermal changes would act to increase the pressure in the baloon
and the rest of the system in general.  Such changes might also moderately
alter the specific deformation of the baloon, but such phenomena are material
dependant.


My question:

In a weightless environment a jar of water with an air bubble inside
is allowed to come to relative equilibrium (Standard Pressure and
Temperature, accelerations = 0, eddies negligible).  What is the
appearance and position of the bubble?
-- 
                   _ _     _ _     _ _
  -Spence         [O.O]   )x.x(   )O.O(
                    O       O      -*-
Newsgroups: rec.puzzles
From: dwr2560@zeus.tamu.edu (RING, DAVID WAYNE)
Subject: Re: blue eyes, brown eyes revisited.
News-Software: VAX/VMS VNEWS 1.41    
Organization: Texas A&M University, Academic Computing Services
Date: Tue, 13 Oct 1992 18:43:00 GMT

<RVESTERM@vma.cc.nd.edu> writes...
>what is all this talk about the blue-eyed natives dying on the 300th day?
>the natives get together as soon as the visitor ships off, and everyone
>is assigned an integer from 1 to 1000 (with everyone getting a different
>integer).
> 
>number one gets up on stage.  he asks, "what color eyes do i have?"
>the masses tell him, truthfully.  if he has blue eyes, everybody goes home,
>and he kills himself that night.  if he has brown eyes, he sits down, and
>number two gets up on stage.  he asks [repeat the process]....

I like it! But it probably won't work. If there is only one blue eye, he
will tell everyone the meeting is a waste of thier time (unfortunately,
this is the logical thing to do, since taking time off is a burden on the
poor islanders). If there are two
blue-eyes they will each wait for the other to tell everyone the meeting
is a waste of time. When niether does, then one of them 'announces' at the
meeting, and they both kill themselves that night. The induction proceeds from
there. Note that the blue-eyes lose one day of life because of this meeting.
Since everyone realizes this ahead of time, noone will suggest the meeting.

:)

Dave Ring
dwr2560@zeus.tamu.edu
Newsgroups: rec.puzzles
From: gbloom@nyx.cs.du.edu (Gregory Bloom)
Subject: Re: Another poser
X-Disclaimer: Nyx is a public access Unix system run by the University
	of Denver for the Denver community.  The University has neither
	control over nor responsibility for the opinions of users, and
	would not know what to do with it if it had.
Keywords: That would be telling...
Organization: Nyx, Public Access Unix at U. of Denver Math/CS dept.
Date: Thu, 8 Oct 92 03:09:59 GMT

In article <1992Sep30.173317.23798@cas.org> lrm28@cas.org () writes:
>List words of 4 letters or more which have the highest ratio
>of vowels to consonants.
>
>Ex.  eerie has 4 vowels to one consonant, or 80% vowels.
>
>Now where did I put that dictionary...

Not as normal, but how 'bout "queueier", as in 'Disney world is a far
queueier place than Epcot'?

75% vowels, all in a row.

Gregory Bloom
gbloom@nyx.cs.du.edu

Newsgroups: rec.puzzles
From: "matthew drew" <mdrew@loanshark.cs.indiana.edu>
Subject: Re: Chess problem 2
Keywords: queens checkmate
Organization: Indiana University, Bloomington
Date: Fri, 9 Oct 1992 10:55:13 -0500

baljeual@uther.calvin.edu (Alan Baljeu) writes
> Ok, What's the most queens you can have without causing checkmate.
> Give a position with n queens (n is huge) so that you can place 
> a lone king somewhere on the board where he won't be in checkmate.

The obvious solution is to put the king in a corner and leave that
row, column, and diagonal bereft of queens.  The other 42 squares
can have queens that don't threaten our poor hopelessly outnumbered
hero.

--
                  Matthew C. Drew (mdrew@cs.indiana.edu)

Newsgroups: rec.puzzles
From: baljeual@uther.calvin.edu (Alan Baljeu)
Subject: Re: Word ending in 5 Consonants (SPOILER)
Organization: Calvin College
Date: Thu, 8 Oct 1992 23:31:21 GMT

clong@remus.rutgers.edu (Chris Long) writes:

>In article <1992Oct8.021445.23776@nas.nasa.gov>, Daniel A. Asimov writes:

>> Can you think of a word fitting this description?

>"lengths" is one such.
>-- 
>Chris Long, 265 Old York Rd., Bridgewater, NJ  08807-2618
come to think of it, so is "strengths"
From: mk0e@ns1.cc.lehigh.edu (MAHEENDRA BABURAO KASMALKAR)
Newsgroups: rec.puzzles
Subject: Re: More logic puzzles please, here's one to try...
Date: 7 Oct 92 21:23:18 GMT
Organization: Lehigh University

In article <48292@shamash.cdc.com>, mpe@shamash.cdc.com writes:
>
>Here's a classic logic problem that I got, oh, probably 20 years
>ago.  I still pull it out every so often for a new group of people.
>
>1. There are five house, each of a different color and
>   inhabited by men of different nationalities, with
>   different pets, drinks, and cigarettes.
>
>2. The Englishman lives in the red house.
>
>3. The Spaniard owns the dog.
>
>4. Coffee is drunk in the green house.
>
>5. The Ukrainian drinks tea.
>
>6. The green house is immediately to the right (your
>   right) of the ivory house.
>
>7. The Old Gold smoker owns snails.
>
>8. Kools are smoked in the yellow house.
>
>9. Milk is drunk in the middle house.
>
>10. The Norwegian lives in the first house on the left.
>
>11. The man who smokes Chesterfields lives in the house
>    next to the man with the fox.
>
>12. Kools are smoked in the house next to the house
>    where the horse is kept.
>
>13. The Lucky Strike smoker drinks orange juice.
>
>14. The Japanese smokes Parliaments.
>
>15. The Norwegian lives next to the blue house.
>
>Now, who drinks water?  And who owns the zebra?
>

Spoiler alert:



















Norwegian drinks water and Japanese owns zebra.

Maheendra
-- 
------------------------------------------------------------------
!  My life in US :            !      Maheendra Kasmalkar         !
!                             !      mk0e@lehigh.edu             !
!  Apartment , Department     !      mk0e@ns1.cc.lehigh.edu      !
!  Advisor and Budweiser      !      (215)-758-8081              !
------------------------------------------------------------------
Newsgroups: rec.puzzles
From: dwr2560@zeus.tamu.edu (RING, DAVID WAYNE)
Subject: Re: Height of a building
News-Software: VAX/VMS VNEWS 1.41    
Organization: Texas A&M University, Academic Computing Services
Date: Thu, 8 Oct 1992 22:20:00 GMT

dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER) writes:
>> How would you accurately measure the height of a ten or twelve
>> story building?
>> 
>> Tools at your disposal include a cigarette lighter, a plastic
>> [ ... ]
>> Accuracy of plus or minus one meter is required.

Plug one end of the tube. Fill the tube with water. Plug the other end
of the tube. Make sure there is no air in the tube. Insert the tube
into the goldfish bowl and remove the lower plug. You now have a barometer.
The upper end of the tube will be vacuum. Replace the lower plug. Remove
the tube and carefully lean the tube at an angle so you can mark the water
level accurately (within ~1 mm). Repeat the procedure on the roof. Make
sure the angle is the same. The marks should be shifted by about 5cm.

I assume we have a table of physical constants so we know the density of air.
Otherwise we have more work to do. :-)

Dave Ring
dwr2560@zeus.tamu.edu
Date: Monday, 12 Oct 1992 23:15:18 EST
From: <RVESTERM@vma.cc.nd.edu>
Newsgroups: rec.puzzles
Subject: Re: blue eyes, brown eyes revisited.

and, of course, the natives pass a law that everyone must wear sunglasses
whenever visitors are on the island, having learned from their mistake.
From: rmurphy@aludra.usc.edu (Bob Murphy)
Newsgroups: rec.puzzles
Subject: Re: Cliff Puzzle 7: 3x3 recursion
Date: 16 Oct 92 12:36:13 GMT
Article-I.D.: aludra.1bnu6tINNn7r
Organization: University of Southern California, Los Angeles, CA
NNTP-Posting-Host: aludra.usc.edu

In article <1blrk9INN10s@aludra.usc.edu> rmurphy@aludra.usc.edu (Bob Murphy) writes:
>In article <1992Oct15.225047.18543@watson.ibm.com> cliff@watson.ibm.com (cliff) writes:

>By exhaustive search I found that there are only 4 starting numbers
>which produce a 3x3 array with the desired property.  Here they are:
>
>   1 9 2        2 1 9        2 7 3        3 2 7
>   3 8 4        4 3 8        5 4 6        6 5 4
>   5 7 6        6 5 7        8 1 9        9 8 1 
>

Subject to cliff's rules of formation, the above 3x3 arrays are the ONLY 
ones which use each of the digits from 1 thru 9 exactly once.

I was pretty lax in my explanation of why the answer to the second
part of cliff's puzzle #7 was NO.  We are told to take the last
row of one of these 3x3 arrays and make it the first row of a new
3x3 array.  Create the new 3x3 array in the same fashion as before.
That is, treat the first row as a 3 digit number.  Double the first
row to get the second row and triple the first row to get the third
row.  Everything is done mod 1000 (i.e. just look at the last 3 digits.)

We get the following new 3x3 arrays:

    5 7 6        6 5 7        8 1 9        9 8 1
    1 5 2        3 1 4        6 3 8        9 6 2
    7 2 8        9 7 1        4 5 7        9 4 3

None of these satisfies the desired property of having each digit from
1 thru 9 used exactly once.  Hence the answer to the second part of the
puzzle is NO.

Looking back over this explanation, maybe I am still being lax.
Oh well, I hope it is clear enough to follow.

Bob Murphy (rmurphy@aludra.usc.edu)
Newsgroups: rec.puzzles
From: huh@wccf.mit.edu (GENE SIMON HUH)
Subject: teez brainbuster
News-Software: VAX/VMS VNEWS 1.41    
Keywords: peg puzzle
Organization: MIT - Whitaker College
Date: Sun, 11 Oct 1992 07:08:00 GMT

Dear puzzlers,

     I have a puzzle at my house called "Teez Brainbuster".  It consists of 
nine holes in a block of plastic, all lined up.  The initial setup of the 
puzzle consists of four blue pegs in holes #1 thru #4 and four red pegs in 
holes #6 thru #9, like this:

         B B B B O R R R R

where B = blue peg
      R = red peg
 and  O = empty hole

The object is to switch the positions of the blue and red pegs, i.e.,

        R R R R O B B B B 

The allowable moves are: 
  a) move one blue peg into an adjacent empty hole
  b) move one red peg into an adjacent empty hole
  c) a peg may "jump" over one (and only one) peg of either color, provided 
that the hole that the peg "jumps" into is empty 
  d) blue pegs can only be moved to the right; red pegs can only be moved to 
the left

     The solution is NOT to turn the plastic block around 180 degrees. :-)

     Normally I'm all right at puzzles, but I can't figure this one out.  I 
didn't see it in the FAQ, so here it is.  Has anybody got the solution handy?  
If so, are my rules (for allowable moves) incorrect?

Thanks in advance,

Gene Huh
huh@wccf.mit.edu  or  huh@mitwccf
From: dsbb@ns1.cc.lehigh.edu (D. SPENCER BEECHER)
Newsgroups: rec.puzzles
Subject: Re: Diameter of earth?
Date: 7 Oct 92 18:16:30 GMT
Organization: Lehigh University


>I think the easiest method would be to measure the Earth's shadow on
>the moon during a lunar eclipse.

>Dave Dodson

But, how far away is the moon? (I assume you would require this
knowledge for your calculations)

If you pick a prominent tall landmark (such as a mountain peak) and travel
away from it, you can determine the earth's curvature by the distance you've
travelled, the altitude of the landmark and your altitude at the point where
the landmark just disappears over the horizon.  Error is introduced if you
don't travel a level path away from the landmark, but that is easy to account
for if you measure altitude differences on your path.  If your path is nearly
level, such an error should be inconsequential.
Get a topographical map and a good telescope.
-- 
                   _ _     _ _     _ _
  -Spence         [O.O]   )x.x(   )O.O(
                    O       O      -*-
Newsgroups: rec.puzzles
From: onar@hsr.no (Onar Aam)
Subject: Chess problem (answer)
Organization: Rogaland University Centre
Date: Wed, 7 Oct 1992 15:35:31 GMT


As many discovered, 5 is the smallest number of queens which will force checkmate
regardless of the kings position.

However, 4 queens are sufficient for stalemate.

The positions d4, d5, e4, e5 yields stalemate provided that the king is not 
allowed to be checked in his initial position.



Onar.
From: tjgerman@53iss6.Waterloo.NCR.COM (Trevor German)
Newsgroups: rec.puzzles
Subject: PACKING DENSITY
Date: 9 Oct 92 15:08:18 GMT
Organization: Imaging Systems Division, NCR Corp, Waterloo, Ont., CANADA


	The person who answered the question with the circles
	arranged such they form inverted offset triagles was 
	quite correct.  The way I loke to think of it is to
			take three rows of circles packed in the
	 		standard maximum density configuration
	  x x o x x      as shown on th right
	   x o o x	and compress the rows
		        such that the rows            \/
	sheer together keeping the circles     ---------------
	in groups of three. What you end up    o o o o o o o o
	with is an expansion outwards but       o o o o o o o
	still maintaining minimum area.        o o o o o o o o
                                               ---------------

		What you end up with is each header circle touches
	five others and each base circle touches four. The maths is
	not as difficult as it sounds. Calculate the repeat distance 
	for six circles using trig and pythagerous and you will find
	that rectangular packing yields a repeat distance of 6 while
	the above gives 5.9639. or put another way 0.6% better packing.

		Of course in a real situation you have to take into
	acount that you loose just over half a circle in the lead 
	corner, so you dont get a pay back till after 84 circles or so.
	
		0.6% doen't sound like much but it is an infinately long
	strip so you can pack infanately more circles...AAARRRGGG. Thats
	another story.


	do the maths you will find that 
--
       >|  "Only average people            | Trevor J German BSc    |<
       >|        never make mistakes."     | NCR, Waterloo, Ontario |<
       >| tjgerman@53iss6.Waterloo.NCR.COM | Canada.                |<
From: msp@dcs.warwick.ac.uk (Mike Paterson)
Newsgroups: rec.puzzles
Subject: Re: Packing problem
Date: 8 Oct 92 08:57:24 GMT
Organization: Department of Computer Science, Warwick University, England

In article <1992Oct6.020647.4651@ils.nwu.edu> blum@news.ils.nwu.edu (Daniel Blum) writes:
>A few years ago, this puzzle appeared in the newsletter of the company
>I was working for:
>
>   Given an infinitely long rectangular strip which is two units wide,
>and circles with diameters of one unit, one can pack them in parallel
>rows of two, like so:
>                      _____________________________
>                      |oooooooooooooooooooooooooooo...
>                      |oooooooooooooooooooooooooooo...
>                      -----------------------------
>However, there is a more efficient packing.  What is it?

If we displace one row to the right by half a unit then gaps open between 
the two rows. Now there is room to wiggle each row a little, saving length.
The real puzzle is how to achieve and prove optimality.

-- 
 Internet,EARN/BITNET,UUCP: msp@dcs.warwick.ac.uk | Mike Paterson 
 JANET: msp@uk.ac.warwick.dcs                     | Dept. of Computer Science
 PHONE: +44 203 523194                            | University of Warwick     
 FAX:   +44 203 525714                            | Coventry, CV4 7AL, ENGLAND
From: prking@silver.cs.umanitoba.ca (Peter King)
Newsgroups: rec.puzzles
Subject: Re: What's the answer to this ough problem?
Date: 9 Oct 92 15:19:47 GMT
Organization: Computer Science, University of Manitoba, Winnipeg, Canada

In article <baljeual.718587223@uther> baljeual@uther.calvin.edu (Alan Baljeu) writes:
>ough
>
>A long time ago in a spelling book, I learned that there are 4 different
>ways to pronounce the above 4 letter sequence, depending on the word that 
>contains it.  However, that is wrong.  What's the real answer anyone?
>
>(Bonus points if you get the answer without dictionaries or other helps)
>Please exhibit words that match.
>

cough rough through though bough
off   stuff do      go     how

Did not use a dictionary. Hm -- are there 6?

Peter King
prking@cs.UManitoba.ca
Newsgroups: rec.puzzles