largest no

[bele_harshad2006]

how can i pick up largest no from 5 rows by 5 column matrix????

[Joachim Schmitz]

"CBFalconer " <cb********@yah oo.comschrieb im Newsbeitrag
news:46******** *******@yahoo.c om...

ma**********@po box.com wrote:

>Richard Heathfield <[e-mail].i nvalidwrote:

>> mark_blue...@po box.com said:
On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:

how can i pick up largest no from 5 rows by 5 column matrix????

Step 1. Sort the columns of each row into ascending order.
Step 2. Sort the rows into ascending order using the last column as
the key.
Step 3. Pick the last column of the last row.

I'm sure we can do better than O(c log c + r log r). Perhaps we
should specify a particular sort. That can get us right up to
O(c^2 + r^2) without any major effort. But can anyone find an
exponential-time algorithm?

There's a big problem here, though - how can we sort anything when
we don't know how to tell whether one thing is larger than another?

You apparantly totally missed the humor involved in RH's post.

Me too I must admit. Isn't that what smileys have been invented for?

Bye, Jojo

[Keith Thompson]

Richard Heathfield <rj*@see.sig.in validwrites:

ma**********@po box.com said:

>On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:

>>how can i pick up largest no from 5 rows by 5 column matrix????

Step 1. Sort the columns of each row into ascending order.
Step 2. Sort the rows into ascending order using the last column as
the key.
Step 3. Pick the last column of the last row.

I'm sure we can do better than O(c log c + r log r). Perhaps we should
specify a particular sort. That can get us right up to O(c^2 + r^2)
without any major effort. But can anyone find an exponential-time
algorithm?

Google "permutatio n sort".

--
Keith Thompson (The_Other_Keit h) 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"

[Denis Kasak]

On 06/06/2007 18:29, Joachim Schmitz wrote:

"CBFalconer " <cb********@yah oo.comschrieb im Newsbeitrag
news:46******** *******@yahoo.c om...

>ma**********@po box.com wrote:

>>Richard Heathfield <[e-mail].i nvalidwrote:
mark_blue...@po box.com said:
On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:
>
>how can i pick up largest no from 5 rows by 5 column matrix????

Step 1. Sort the columns of each row into ascending order.
Step 2. Sort the rows into ascending order using the last column as
the key.
Step 3. Pick the last column of the last row.

I'm sure we can do better than O(c log c + r log r). Perhaps we
should specify a particular sort. That can get us right up to
O(c^2 + r^2) without any major effort. But can anyone find an
exponentia l-time algorithm?

There's a big problem here, though - how can we sort anything when
we don't know how to tell whether one thing is larger than another?

You apparantly totally missed the humor involved in RH's post.

Me too I must admit. Isn't that what smileys have been invented for?

A smiley would ruin the joke considerably, I must say.

--
Denis Kasak

[Tor Rustad]

Richard Heathfield wrote:

ma**********@po box.com said:

>On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:

>>how can i pick up largest no from 5 rows by 5 column matrix????

I'm sure we can do better than O(c log c + r log r). Perhaps we should
specify a particular sort. That can get us right up to O(c^2 + r^2)
without any major effort. But can anyone find an exponential-time
algorithm?

Arrgh.. exponential-time??! The worst sorting algorithms I know, are
O(N^2). :-/

I can't remember Knuth or Sedgewick, discussing anything worse than that.

Give a hint please..

--
Tor <torust [at] online [dot] no>

[Richard Heathfield]

Tor Rustad said:

Richard Heathfield wrote:

> ma**********@po box.com said:

>>On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:
how can i pick up largest no from 5 rows by 5 column matrix????

>I'm sure we can do better than O(c log c + r log r). Perhaps we
should specify a particular sort. That can get us right up to O(c^2 +
r^2) without any major effort. But can anyone find an
exponential-time algorithm?

Arrgh.. exponential-time??! The worst sorting algorithms I know, are
O(N^2). :-/

I can't remember Knuth or Sedgewick, discussing anything worse than
that.

Give a hint please..

Well, let's see now...

while not sorted
exchange two elements at random
endwhile

That would do it, I think.

--
Richard Heathfield
"Usenet is a strange place" - dmr 29/7/1999
http://www.cpax.org.uk
email: rjh at the above domain, - www.

[Keith Thompson]

Keith Thompson <ks***@mib.orgw rites:

Richard Heathfield <rj*@see.sig.in validwrites:

> ma**********@po box.com said:

>>On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:
how can i pick up largest no from 5 rows by 5 column matrix????

Step 1. Sort the columns of each row into ascending order.
Step 2. Sort the rows into ascending order using the last column as
the key.
Step 3. Pick the last column of the last row.

I'm sure we can do better than O(c log c + r log r). Perhaps we should
specify a particular sort. That can get us right up to O(c^2 + r^2)
without any major effort. But can anyone find an exponential-time
algorithm?

Google "permutatio n sort".

Sorry, permutation sort isn't exponential-time. (It's worse.)

--
Keith Thompson (The_Other_Keit h) 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"

[Joe Wright]

be************* *@yahoo.co.in wrote:

how can i pick up largest no from 5 rows by 5 column matrix????

No matrices in C, sorry. We do have arrays though. Consider..

int arr[5][5];

Does this satisfy your description of a matrix?

The arr array has 25 elements. We can find the largest of them by simply
tripping through the array comparing 'this' one to the previously larger
one. The position of the largest element in the array might also be of
interest. Consider..

int i, j, r, c, max = 0;

for (i = 0; i < 5; ++i)
for (j = 0; j < 5; ++j)
if (arr[i][j] max) {
max = arr[i][j];
r = i, c = j;
}

When this finishes, max will hold the largest int and r and c will tell
you where it is. And very quickly.

--
Joe Wright
"Everything should be made as simple as possible, but not simpler."
--- Albert Einstein ---

[Keith Thompson]

Richard Heathfield <rj*@see.sig.in validwrites:

Tor Rustad said:

>Richard Heathfield wrote:

>> ma**********@po box.com said:
On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:
how can i pick up largest no from 5 rows by 5 column matrix????

>>I'm sure we can do better than O(c log c + r log r). Perhaps we
should specify a particular sort. That can get us right up to O(c^2 +
r^2) without any major effort. But can anyone find an
exponential-time algorithm?

Arrgh.. exponential-time??! The worst sorting algorithms I know, are
O(N^2). :-/

I can't remember Knuth or Sedgewick, discussing anything worse than
that.

Give a hint please..

Well, let's see now...

while not sorted
exchange two elements at random
endwhile

That would do it, I think.

If the exchanges are truly random, that's not guaranteed to terminate,
so it doesn't qualify as an algorithm.

--
Keith Thompson (The_Other_Keit h) 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"

[CBFalconer]

Tor Rustad wrote:

Richard Heathfield wrote:

>ma**********@po box.com said:

>>On 6 Jun, 10:50, bele_harshad2.. [e-mail] wrote:

how can i pick up largest no from 5 rows by 5 column matrix???

>I'm sure we can do better than O(c log c + r log r). Perhaps we
should specify a particular sort. That can get us right up to
O(c^2 + r^2) without any major effort. But can anyone find an
exponential-time algorithm?

Arrgh.. exponential-time??! The worst sorting algorithms I know,
are O(N^2). :-/

I can't remember Knuth or Sedgewick, discussing anything worse
than that.

Give a hint please..

I don't know the O(), but try simply rearranging the sortee at
random, then check if sorted. If not, repeat.

--
<http://www.cs.auckland .ac.nz/~pgut001/pubs/vista_cost.txt>
<http://www.securityfoc us.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

[CBFalconer]

Keith Thompson wrote:

Richard Heathfield <rj*@see.sig.in validwrites:

>Tor Rustad said:

.... snip ...

>>

>>Arrgh.. exponential-time??! The worst sorting algorithms I know,
are O(N^2). :-/

I can't remember Knuth or Sedgewick, discussing anything worse
than that.

Give a hint please..

Well, let's see now...

while not sorted
exchange two elements at random
endwhile

That would do it, I think.

If the exchanges are truly random, that's not guaranteed to
terminate, so it doesn't qualify as an algorithm.

Yes it is, given sufficient time and a really random generator :-)

--
<http://www.cs.auckland .ac.nz/~pgut001/pubs/vista_cost.txt>
<http://www.securityfoc us.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