473,413 Members | 2,058 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,413 software developers and data experts.

a good worthy project ??

hi friends
i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it
thanks

May 17 '07 #1
18 1340
"prashanth" wrote:
i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it
A sudoku solver or a sudoku problem generator.
May 17 '07 #2

"osmium" <r1********@comcast.netwrote in message
news:5b*************@mid.individual.net...
"prashanth" wrote:
>i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it

A sudoku solver or a sudoku problem generator.
Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?
May 17 '07 #3
"Barry" wrote:
>>i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it

A sudoku solver or a sudoku problem generator.
Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?
It's not even close. There are only five billion or so people on Earth. But
there are about
6670903752021072936960 sudoku puzzles, which is about 10^21.

May 17 '07 #4
osmium wrote:
"Barry" wrote:
>>>i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it
A sudoku solver or a sudoku problem generator.
>Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?

It's not even close. There are only five billion or so people on Earth. But
there are about
6670903752021072936960 sudoku puzzles, which is about 10^21.
But, do all those actually need to be solved?
May 17 '07 #5

"Clever Monkey" <sp******@clevermonkey.org.INVALIDwrote in message
news:JA****************@nnrp.ca.mci.com!nnrp1.uune t.ca...
osmium wrote:
>"Barry" wrote:
>>>>i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it
A sudoku solver or a sudoku problem generator.
>>Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?

It's not even close. There are only five billion or so people on Earth.
But there are about
6670903752021072936960 sudoku puzzles, which is about 10^21.
But, do all those actually need to be solved?
Acutally, I was being facetious. The sudoku solver has been beaten
to death. I wrote one a couple of years ago. Actually there are only
5,472,730,538 unique boards when you take symmetries into account.
May 17 '07 #6
osmium said:
"Barry" wrote:
>>>i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it

A sudoku solver or a sudoku problem generator.
>Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?

It's not even close. There are only five billion or so people on
Earth.
Can we assume there are 6670903752, please? Ta muchly.
But there are about
6670903752021072936960 sudoku puzzles, which is about 10^21.
In other words, every man, woman and child on the planet has written
about 1000000000000 solvers. That sounds about right, actually...

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.
May 17 '07 #7
Richard Heathfield wrote:
osmium said:
>"Barry" wrote:
>>>>i know c and c++ somewat wel
i want to do a project in it
can anyone suggest me a good theme for it
A sudoku solver or a sudoku problem generator.
Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?
It's not even close. There are only five billion or so people on
Earth.

Can we assume there are 6670903752, please? Ta muchly.
Not any more...

--
Ian Collins.
May 17 '07 #8
"Barry" writes:
>>>>>i know c and c++ somewat wel
>i want to do a project in it
>can anyone suggest me a good theme for it
A sudoku solver or a sudoku problem generator.

Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?

It's not even close. There are only five billion or so people on Earth.
But there are about
6670903752021072936960 sudoku puzzles, which is about 10^21.
But, do all those actually need to be solved?

Acutally, I was being facetious. The sudoku solver has been beaten
to death. I wrote one a couple of years ago. Actually there are only
5,472,730,538 unique boards when you take symmetries into account.
Boy, it takes a huge bunch of symmetries to get from my number to yours!!
The source of my number is at the end of this message. Where did your
number come from?

As far as being beaten to death, I don't see the connection between a new
programmer and the fact that many people have attacked the same problem. Do
you think the new guy learns from emanations in the aether or something? I
think it is a problem that is easy to understand, so the OP can spend his
time solving it rather than spending a lot of time figuring out exactly
what the problem is. A lot of problems that would otherwise be good have
this shortcoming - a complicated problem definition. Another problem where
it is easy to understand the problem statement is chess. . Neither of
these need any digressions into graphics and such like, either.

http://theory.tifr.res.in/~sgupta/sudoku/expert.html
May 17 '07 #9

"osmium" <r1********@comcast.netwrote in message
news:5b*************@mid.individual.net...
"Barry" writes:
>>>>>>i know c and c++ somewat wel
>>i want to do a project in it
>>can anyone suggest me a good theme for it
>A sudoku solver or a sudoku problem generator.

Aren't there already more sudoku solvers and
generators than there are possible sudoku puzzles?

It's not even close. There are only five billion or so people on Earth.
But there are about
6670903752021072936960 sudoku puzzles, which is about 10^21.

But, do all those actually need to be solved?

Acutally, I was being facetious. The sudoku solver has been beaten
to death. I wrote one a couple of years ago. Actually there are only
5,472,730,538 unique boards when you take symmetries into account.

Boy, it takes a huge bunch of symmetries to get from my number to yours!!
The source of my number is at the end of this message. Where did your
number come from?

As far as being beaten to death, I don't see the connection between a new
programmer and the fact that many people have attacked the same problem.
Do you think the new guy learns from emanations in the aether or
something? I think it is a problem that is easy to understand, so the OP
can spend his time solving it rather than spending a lot of time figuring
out exactly what the problem is. A lot of problems that would otherwise
be good have this shortcoming - a complicated problem definition. Another
problem where it is easy to understand the problem statement is chess. .
Neither of these need any digressions into graphics and such like, either.

http://theory.tifr.res.in/~sgupta/sudoku/expert.html
A sudoku can be solved with a very short recursive function. It's not
inherently
much of a programming task.

When I said symmetries I was including remapping as a case of symmetry.

http://www.afjarvis.staff.shef.ac.uk.../sudgroup.html
May 18 '07 #10
osmium wrote:
"Barry" writes:
.... snip (somebody deleted attributions) ...
>>>>
It's not even close. There are only five billion or so people
on Earth. But there are about 6670903752021072936960 sudoku
puzzles, which is about 10^21.

But, do all those actually need to be solved?

Acutally, I was being facetious. The sudoku solver has been
beaten to death. I wrote one a couple of years ago. Actually
there are only 5,472,730,538 unique boards when you take
symmetries into account.

Boy, it takes a huge bunch of symmetries to get from my number
to yours!! The source of my number is at the end of this message.
Where did your number come from?
9! is about 3.5 * 10e6. This gets things within a factor of 100 or
so. Now look for other permutations, such as horizontal and
vertical interchanges.

--
<http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.txt>
<http://www.securityfocus.com/columnists/423>
<http://www.aaxnet.com/editor/edit043.html>
<http://kadaitcha.cx/vista/dogsbreakfast/index.html>
cbfalconer at maineline dot net

--
Posted via a free Usenet account from http://www.teranews.com

May 18 '07 #11
CBFalconer said:

<snip>
9! is about 3.5 * 10e6.
To be specific, it's 362880, so you're out by an order of magnitude.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.
May 18 '07 #12
Richard Heathfield <rj*@see.sig.invalidwrites:
CBFalconer said:

<snip>
>9! is about 3.5 * 10e6.

To be specific, it's 362880, so you're out by an order of magnitude.
No, you're off by an order of magnitude; he's off by two.

(10e6 is 10 million, not 1 million.)

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
May 19 '07 #13
Keith Thompson said:
Richard Heathfield <rj*@see.sig.invalidwrites:
>CBFalconer said:

<snip>
>>9! is about 3.5 * 10e6.

To be specific, it's 362880, so you're out by an order of magnitude.

No, you're off by an order of magnitude;
....in the last part of my statement, yes.
he's off by two.

(10e6 is 10 million, not 1 million.)
And I thought /I/ had an eye for detail! :-) Thanks for the correction.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.
May 19 '07 #14
Keith Thompson wrote:
Richard Heathfield <rj*@see.sig.invalidwrites:
>CBFalconer said:

<snip>
>>9! is about 3.5 * 10e6.

To be specific, it's 362880, so you're out by an order of
magnitude.

No, you're off by an order of magnitude; he's off by two.

(10e6 is 10 million, not 1 million.)
It'll take a while to live this one down :-(.

--
<http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.txt>
<http://www.securityfocus.com/columnists/423>
<http://www.aaxnet.com/editor/edit043.html>
<http://kadaitcha.cx/vista/dogsbreakfast/index.html>
cbfalconer at maineline dot net

--
Posted via a free Usenet account from http://www.teranews.com

May 19 '07 #15
"CBFalconer" writes:
osmium wrote:
>"Barry" writes:
... snip (somebody deleted attributions) ...
>>>>>
It's not even close. There are only five billion or so people
on Earth. But there are about 6670903752021072936960 sudoku
puzzles, which is about 10^21.
>
But, do all those actually need to be solved?

Acutally, I was being facetious. The sudoku solver has been
beaten to death. I wrote one a couple of years ago. Actually
there are only 5,472,730,538 unique boards when you take
symmetries into account.

Boy, it takes a huge bunch of symmetries to get from my number
to yours!! The source of my number is at the end of this message.
Where did your number come from?

9! is about 3.5 * 10e6. This gets things within a factor of 100 or
so. Now look for other permutations, such as horizontal and
vertical interchanges.
OK, that kind of establishes one boundary. The other boundary is 81! which
I believe is about 5.79 x 10^120. So we are homing in on the answer!

That's based on the guess that you just made up 100, it sounds too "round"
to be accurate. And besides that, "or so" kind of minimizes any claims to
accuracy. I don't want to spend the rest of my life on this, but I really
would like to know whose expert is closer to right, my expert or the other
one. If anyone comes across another source, or a critique of either of
these two sources, I would like to know of it.
May 19 '07 #16
osmium said:
"CBFalconer" writes:
>9! is about 3.5 * 10e6. This gets things within a factor of 100 or
so. Now look for other permutations, such as horizontal and
vertical interchanges.

OK, that kind of establishes one boundary. The other boundary is 81!
which
I believe is about 5.79 x 10^120. So we are homing in on the answer!
Looks about right. But of course we can constrain it further than that.
Each row has 9! possibilities, and *even if they are independent*
(which they are not), we need only consider (9!)^9 combinations, which
is a mere 10911068841557131648034489935589408558284800000000 0, or
approximately 1.09E48, for the upper limit, and which is practically
infinitesimal compared to 5E120.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.
May 19 '07 #17
CBFalconer <cb********@yahoo.comwrites:
Keith Thompson wrote:
>Richard Heathfield <rj*@see.sig.invalidwrites:
>>CBFalconer said:

<snip>

9! is about 3.5 * 10e6.

To be specific, it's 362880, so you're out by an order of
magnitude.

No, you're off by an order of magnitude; he's off by two.

(10e6 is 10 million, not 1 million.)

It'll take a while to live this one down :-(.
Ah, but if we assume that "10e6" was intended to be hexadecimal, and
you merely left off the "0x", then you're only off by a factor of
about 24 (in the opposite direction).

And if we further assume that the '.' in 3.5 is really the Perl string
concatenation operator (which would require surrounding whitespace in
this context), then you're remarkably close:

3 . 5 * 0x10e6 =
3 . (5 * 0x10e6) =
3 . (5 * 4326) =
3 . 21630 =
321630

which is only about 11% smaller than the correct answer, 362880.

If you had used 3.15 rather than 3.5, you'd be within 1%. Perhaps the
missing 1 was merely a typo. That's a minor error compared to the
missing "0x", the missing whitespace around the "." operator, and the
use of Perl rather than C.

So don't feel too bad about it.

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <* <http://users.sdsc.edu/~kst>
"We must do something. This is something. Therefore, we must do this."
-- Antony Jay and Jonathan Lynn, "Yes Minister"
May 19 '07 #18
Barry wrote:
"Clever Monkey" <sp******@clevermonkey.org.INVALIDwrote:
.... snip ...
>
>But, do all those actually need to be solved?

Acutally, I was being facetious. The sudoku solver has been beaten
to death. I wrote one a couple of years ago. Actually there are only
5,472,730,538 unique boards when you take symmetries into account.
If that is accurate, it is about 1 per person in the world.

--
<http://www.cs.auckland.ac.nz/~pgut001/pubs/vista_cost.txt>
<http://www.securityfocus.com/columnists/423>
<http://www.aaxnet.com/editor/edit043.html>
<http://kadaitcha.cx/vista/dogsbreakfast/index.html>
cbfalconer at maineline dot net

--
Posted via a free Usenet account from http://www.teranews.com

May 21 '07 #19

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

11
by: cj | last post by:
Public Class MyStringLogger Private Shared m_loglock As New Object Public Shared Sub Write(ByVal str As String) SyncLock (m_loglock) Dim sw As New System.io.StreamWriter("c:\validate.log",...
3
by: okay | last post by:
Hello, http://www.av1611.org/666/biochip.html To Archbishop Christodoulos Paraskevaides of the Greek Orthodox Church in Athens and Greece Archbishop, I talked with a Greek Orthodox...
63
by: John Salerno | last post by:
I know there's a request for a good IDE at least once a week on the ng, but hopefully this question is a little different. I'm looking for suggestions for a good cross-platform text editor (which...
1
by: nemocccc | last post by:
hello, everyone, I want to develop a software for my android phone for daily needs, any suggestions?
1
by: Sonnysonu | last post by:
This is the data of csv file 1 2 3 1 2 3 1 2 3 1 2 3 2 3 2 3 3 the lengths should be different i have to store the data by column-wise with in the specific length. suppose the i have to...
0
Oralloy
by: Oralloy | last post by:
Hello folks, I am unable to find appropriate documentation on the type promotion of bit-fields when using the generalised comparison operator "<=>". The problem is that using the GNU compilers,...
0
jinu1996
by: jinu1996 | last post by:
In today's digital age, having a compelling online presence is paramount for businesses aiming to thrive in a competitive landscape. At the heart of this digital strategy lies an intricately woven...
0
by: Hystou | last post by:
Overview: Windows 11 and 10 have less user interface control over operating system update behaviour than previous versions of Windows. In Windows 11 and 10, there is no way to turn off the Windows...
0
tracyyun
by: tracyyun | last post by:
Dear forum friends, With the development of smart home technology, a variety of wireless communication protocols have appeared on the market, such as Zigbee, Z-Wave, Wi-Fi, Bluetooth, etc. Each...
0
agi2029
by: agi2029 | last post by:
Let's talk about the concept of autonomous AI software engineers and no-code agents. These AIs are designed to manage the entire lifecycle of a software development project—planning, coding, testing,...
0
isladogs
by: isladogs | last post by:
The next Access Europe User Group meeting will be on Wednesday 1 May 2024 starting at 18:00 UK time (6PM UTC+1) and finishing by 19:30 (7.30PM). In this session, we are pleased to welcome a new...
0
by: conductexam | last post by:
I have .net C# application in which I am extracting data from word file and save it in database particularly. To store word all data as it is I am converting the whole word file firstly in HTML and...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.