Increasing array size

[Ioannis Hadjichambis]

I am trying to implement a hash-table and I would like to rehash it when
it starts to fill up. I am implementing the hash-table with an array
of linked lists. Now for me to increase the size of the hash-table I
must create a new array twice the size of the one before but the array
only accepts an imediate number eg array[1000] and will not accept a
variable eg array[count]. Does anyone know how to solve this problem?
thanks...

 

[Christian Staudenmayer]

I am trying to implement a hash-table and I would like to rehash it when
it starts to fill up. I am implementing the hash-table with an array
of linked lists. Now for me to increase the size of the hash-table I
must create a new array twice the size of the one before but the array
only accepts an imediate number eg array[1000] and will not accept a
variable eg array[count]. Does anyone know how to solve this problem?
thanks...

Like you would use a dynamic array of a regular type, i.e. using malloc().

Greetings, Chris

 

[dandelion]

I am trying to implement a hash-table and I would like to rehash it when
it starts to fill up. I am implementing the hash-table with an array
of linked lists. Now for me to increase the size of the hash-table I
must create a new array twice the size of the one before but the array
only accepts an imediate number eg array[1000] and will not accept a
variable eg array[count]. Does anyone know how to solve this problem?
thanks...

Try allocating memory dynamically using malloc() instead of declaring a
fixed array. If your hash-table needs to grow, you can use realloc() to grow
the allocated dataspace or move it to a place where sufficient memory can be
allocated.

 

[EventHelix.com]

In C this would require using malloc for the array allocation.

It you were writing this code in C++, this would be an easy problem to
solve using the STL map.

Deepa

 

[CBFalconer]

I am trying to implement a hash-table and I would like to rehash it
when it starts to fill up. I am implementing the hash-table with an
array of linked lists. Now for me to increase the size of the
hash-table I must create a new array twice the size of the one
before but the array only accepts an imediate number eg array[1000]
and will not accept a variable eg array[count]. Does anyone know
how to solve this problem? thanks...

All done and available under GPL. See:

<http://cbfalconer.home.att.net/download/hashlib.zip>

 

[James Dow Allen]

"Require"? ... "Easy"? Let me rephrase Deepa's answers.

In C this would require using malloc for the array allocation.

"In C this is very simple to do with malloc()."

It you were writing this code in C++, this would be an easy problem to
solve using the STL map.

"In C++, many might do this by invoking an unneccessarily complicated
copyrighted library."

If you like C++, you're welcome to it (though not in this newsgroup)
but do let's not confuse the novice with misleading tone.

James

 

[Default User]

James Dow Allen wrote:

"In C++, many might do this by invoking an unneccessarily complicated
copyrighted library."

While this is not a C++ newsgroup, and hence this is off-topic, I'll
briefly note that map is (as of the 1998 standard) part of the C++
standard library.




Brian