Date: 02/21/05     Keywords: no keywords

My final project for AP Computer Science is to write a checkers program where you can play either Human v. Computer or Computer v. Computer. I have chosen to use a basic minimax algorithm, nothing fancy, and was wondering what people's thoughts were on the algorithm to rate each board state.

At the moment I am looking at something to the tune of:
(normal pieces) + (king pieces * 2) + (your total pieces - opponent's total pieces)

Any input would be great.

Thanks.

Source: http://www.livejournal.com/community/algorithms/47375.html

Date: 02/08/05     Keywords: no keywords

What effective algorithms are there for searching for several rather similar samples in a long string? I am sure there exist far more effective ways of solving this problem than simply running KMP or an other fast algorithm for each sample.
The practical application is obvious - search for word forms or similar words, search with correction of orphograpical mistakes..
Another interesting problem is searching by several regexps. For instance, in Mathematica there is a possibility to "compile" a large table of rules to make replacements with it more effective, however this is quite a different type of regexps..

Source: http://www.livejournal.com/community/algorithms/46615.html

Date: 02/07/05     Keywords: no keywords

I'm looking for Developers in Dallas/Fort Worth, TX.  Here's the info.

Source: http://www.livejournal.com/community/algorithms/46451.html

Date: 01/27/05     Keywords: no keywords

I am looking for some possible topic ideas that use approximation algorithms such as ant system or genetic algorithm to solve NP* problems. Any idea & suggestion is appreciated.

Source: http://www.livejournal.com/community/algorithms/45321.html

Date: 01/27/05     Keywords: no keywords

I need to test the memory on a card I'm working on. I've heard of a few algorithms that are good to use (e.g., write all 55s then all AAs). I've also heard names dropped for a few I don't know: "walking zeros," "corkscrew," "matching ones," etc. I don't know what these algorithms do.

If someone knows and/or knows of any other good things to try, could they let me know? I'd really appreciate it.
Thanks!

Source: http://www.livejournal.com/community/algorithms/45079.html

Date: 01/20/05     Keywords: no keywords

Consider two computers connected by a very asymmetric communications system. This means that download is far faster than upload from the POV of one of the computers (from the other, of course, upload is far faster than download).

Then, if A is the one whose upload is slow, and B is the one whose download is slow, is there any way for A, through receiving data from B and adapting, to "upload" a file (give B all of its data) quicker than the nominal upload speed of the line it is connected to, even if the data itself is random (or optimally compressed)?

I know that by the pigeonhole principle, it's impossible to upload faster than the nominal upload speed if B doesn't do anything but receive (or responds with the exact same messages no matter what data is sent). But is it possible to upload faster if B is active within the protocol?

(Perhaps B could rapidly upload combinations, and A would trigger with an acknowledgement when it received the right few next bytes? But even if we had zero latency, this would be slow as we'd have to wait on average until half of the possible combinations were uploaded by B before getting the right one. In extreme conditions, this still might be faster than A uploading directly, but can we do better? What if the connection is lagged?)

Source: http://www.livejournal.com/community/algorithms/44641.html

Date: 01/14/05     Keywords: no keywords

Hi All,

I am trying to figure out an efficient way to update a file on the server from a client.
What I have got is a huge file which clients download from the server. They can then
make changes to it as they like and then upload it from time to time. What I want is a
way to update the file on the server without sending out the whole file as the time cost
over the network is quite a bit.

I tried sending and comparing checksums for file chunks but the updation is non-trivial
( A single addition/deletion/replacement and change checksums for all the following
chunks).

Any suggestions?

Thanks,
J

Source: http://www.livejournal.com/community/algorithms/44447.html

Date: 01/11/05     Keywords: no keywords

Hi All.
Although i have some ideas about subject, i really would like too hear yours. The question is : how to make path finder like in games AOM or WARCRAFT3 ?
Thank you.

P.S. Sorry my english, i'm russian, you know - Moscow, bears..:).

Source: http://www.livejournal.com/community/algorithms/44125.html

Date: 12/28/04     Keywords: no keywords

Hi all!

Does anyone know optimal algorithm to find minimal set of numbers which will sum up to some value?

Example:

Target value is 5, we have set of numbers: 1, 1, 2, 3, 4.
So algorithm should pick 1+4 or 2+3, but not, say, 1+1+3.

Numbers in set can be of any value, quantity if then is not limited.

If you have code snipped - that would be great as well! Language does not matter (as long it is not something like Cobol). :-)

Source: http://www.livejournal.com/community/algorithms/42071.html

Date: 12/26/04     Keywords: no keywords

Has anyone ever seen any research on analyzing cache locality properties of algorithms? Or exploring the effects of bad locality/inefficient caching? I might be doing my Senior Project on that, but was having trouble finding any material on it. Though I suppose the lack of material is precisely why the professor suggested the project.

Let me know if that was too incoherent, and I can explain better in a reply.

Source: http://www.livejournal.com/community/algorithms/41860.html

Date: 12/26/04     Keywords: java

umm im new to computer science im barely taking it as a junior in high school and im learning java.

does anyone know java ?

Source: http://www.livejournal.com/community/algorithms/41315.html

Date: 12/22/04     Keywords: no keywords

UpD: questions answered.
thanks a bunch.

#define false   (0)
#define true    (!false)

unsigned char poop1 :   1;      // yes it a single colon and that's why it doesn't make sense to me...

#define  POOP1    "A"
#define  POOP2    "B"
...

//then there is a table of strings
static const char* const table_of_strings[MAX]=
{
POOP1"This will be a first string",                  //so in memory it just looks like 'AThis will be...'?
POOP2"This will be a second string",
...
};



then there's a function that does something like this...

const char* str = table_of_strings[i];
set_poop(*str-'A');                     //exactly what happens here? pointer to str got subtracted with pointer of 'A'?? or else?


and this is not even it.


Then in another file.... it has this enumerator.

typedef enum TAG
{
 P_1,                    //aren't unspecified enums are just 0,1,2 ?
 P_2,
 ...
} POOP_TAG;


POOP_TAG current_poop;


then that above mentioned function
set_poop() receives poopie parameter from the first file and does the following...

current_poop = poopie;

Source: http://www.livejournal.com/community/algorithms/41163.html

Date: 12/14/04     Keywords: no keywords

How does one piece together two BSplines (each of different Control points and Knot vector) with the continuity of C1? G1 is easy, because no change is required, but C1 is kinda tricky.

Amir.

Source: http://www.livejournal.com/community/algorithms/40885.html

Date: 12/14/04     Keywords: browser, html, web

Here is the gist of some project we are working on

1) ping defined machines

we have a ping.c program based on stevens but slightly modified so as
to suit our project needs , it is basic and only verbose mode has been
provided.

- It outputs to screen if run in verbose mode as ./ping -v localhost 32 2
here 32 is packet length and 2 is the number of packets to be sent for
ICMP echo reply
-we compiled as cc ping.c -o ping

2) portscan and portcheck

we scan all ports via portscan.c program that will scan ports
specified as argiments from start port to end port.
It connects to ports and returns success else error thats all

3) pingme file

this has the hostnames or addresses in dot notation that define whom
to ping upon .

4) pinger shell script

This shell script logs to /var/www/html and file created in pingme.html
-executes the programs mentioned above and basically reads args from
pingme file for the programs.
- the output is logged to html file
-execute as ./pinger

5) open in browser
we open http://localhost/pingme.html in browser



Results is as below

Statistics for ping on Mon Dec 13 21:57:51 IST 2004 from machine
localhost.localdomain

Hostname Reachable? Port 80 Port 21
localhost: yes yes nope

Details:
done:
* ping
* portcheck
* portscan
* script to integrate all components
- add html output

todo for networking project:
* network congestion check
* run all periodically
* add eye-candy to html output

Now this is project specifications we created

Implementation of a network status monitor that can perform these steps

1) ping all defined machines in the network from time to time, and
alert (by an indicator on a web page or screen) when some machine is
down
(2) periodically check HTTP and FTP ports of important machines (like
your intranet server) to verify that services are running and
responding properly
(3) can check if there is any networking problem like ping delay or
HTTP server responding slow
(4) sysadmins can add custom service ports (other than HTTP/FTP) to
their checklist
(5) your application will then check if those ports are open from time to time

1,2,4,5 are done so far ...for 3rd step we think some network
congestion algorithm is needed and implementing it is needed. but
simulation of congestion in lan is going to be tough right...any
solutions ideas.....;)

What more features we can add to this project to make it look l33t and
impressive ....please do suggest some ideas.

Deadline is approaching so please hurry....thanks again.

Source: http://www.livejournal.com/community/algorithms/40484.html