what's the best hash function?

[vietor.liu]

is this?

int hashpjw(char* str,int size)
{
unsigned long h=0,g;
for(unsigned char *p=(unsigned char*)str;*p;++ p)
{
h=(h<<4)+*p;
if(g=(h&0xf0000 000))
{
h^=(g>>24);
h^=g;
}
}
return h%size;
}

[Chris McDonald]

"vietor.liu " <vi********@gma il.com> writes:

is this? int hashpjw(char* str,int size)
{
unsigned long h=0,g;
for(unsigned char *p=(unsigned char*)str;*p;++ p)
{
h=(h<<4)+*p;
if(g=(h&0xf0000 000))
{
h^=(g>>24);
h^=g;
}
}
return h%size;
}

<OT>
The answer totally depends on the type and range of inputs,
and the purpose of the hash result. Read onwards:

http://burtleburtle.net/bob/hash/evahash.html
</OT>

--
Chris.

[Jack Klein]

On Fri, 25 Nov 2005 10:21:54 +0800, "vietor.liu "
<vi********@gma il.com> wrote in comp.lang.c:

Define "best".

is this?

int hashpjw(char* str,int size)
{
unsigned long h=0,g;
for(unsigned char *p=(unsigned char*)str;*p;++ p)
{
h=(h<<4)+*p;
if(g=(h&0xf0000 000))
{
h^=(g>>24);
h^=g;
}
}
return h%size;
}

If you want to know the "best" hashing algorithm, ask in
news:comp.progr amming. And supply a definition of what you consider
to be "best".

Once you have selected an algorithm, if you have problems coding it
correctly in standard C, then you can post your code and description
of your problem here.

--
Jack Klein
Home: http://JK-Technology.Com
FAQs for
comp.lang.c http://www.eskimo.com/~scs/C-faq/top.html
comp.lang.c++ http://www.parashift.com/c++-faq-lite/
alt.comp.lang.l earn.c-c++
http://www.contrib.andrew.cmu.edu/~a...FAQ-acllc.html

[Mabden]

What is the best colour?

--
Mabden

[Joe Estock]

Mabden wrote:

What is the best colour?

Red. No wait, Purple. On second thought, make that Green.

I have no idea what it is you are asking since both the subject line and
the body of your post are completely different and no context is
provided in either. Please be more descriptive when you post as it helps
us better help you.

Joe

[Richard Heathfield]

Joe Estock said:

Mabden wrote:

What is the best colour?

Red. No wait, Purple. On second thought, make that Green.

' . .
ea e o ee e o a
Pl s d n t f d th tr lls Th nks

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

[Christopher Benson-Manica]

Joe Estock <je*****@nospam nutextonline.co m> wrote:

Red. No wait, Purple. On second thought, make that Green.

And what is the airspeed velocity of an unladen swallow?

--
Christopher Benson-Manica | I *should* know what I'm talking about - if I
ataru(at)cybers pace.org | don't, I need to know. Flames welcome.

[Skarmander]

Christopher Benson-Manica wrote:

Joe Estock <je*****@nospam nutextonline.co m> wrote:

Red. No wait, Purple. On second thought, make that Green.

And what is the airspeed velocity of an unladen swallow?

Please read http://www.ungerhu.com/jxh/clc.welcome.txt. Your question is
off-topic for this group. You may have more success getting answers in
comp.lang.pytho n -- this may be a FAQ there.

S.

[pete]

Christopher Benson-Manica wrote:

Joe Estock <je*****@nospam nutextonline.co m> wrote:

Red. No wait, Purple. On second thought, make that Green.

And what is the airspeed velocity of an unladen swallow?

http://faultgame.com/images/quest.wav

--
pete

[David Resnick]

Christopher Benson-Manica wrote:

Joe Estock <je*****@nospam nutextonline.co m> wrote:

Red. No wait, Purple. On second thought, make that Green.

And what is the airspeed velocity of an unladen swallow?

--
Christopher Benson-Manica | I *should* know what I'm talking about - if I
ataru(at)cybers pace.org | don't, I need to know. Flames welcome.

This really sounds like homework. Besides, it is an algorithm
question, so comp.programmin g would be a better place.
Maybe you should try to write a C program to calculate
the average velocity of a number of swallows. If you
present your efforts, I'm sure people will try to give you a
hand. <OT> Hint -- it matters whether it is African or
European </OT>

-David