"Vladimir S. Oka" <novine@btopenworld.com> writes:[color=blue]
> On Wednesday 15 March 2006 06:40,
luke.yolanda@gmail.com opined (in
> <1142404851.856547.287670@u72g2000cwu.googlegroups .com>):
>[color=green]
>> Hi everyone
>> Now i'm designing a random instances generator for maximum clique
>> problem using C.
>> So I planing to implement a adjacent matrix in this generator to store
>> the whole graph going to be generated. I couldn't find a method other
>> than using an unsigned char[][], but in this way, 7 bits in a
>> unsigned char will be wasted. Could anyone teach me a more effective
>> way to implement it? Thank you![/color]
>
> If I understand your problem correctly, you actually want an /adjacency/
> matrix which, if memory serves is just a 0/1 matrix. So, it seems you
> want to pack your bits, instead of using a whole `char` for each one.
> You can still use the same sort of matrix you say you have now, just
> pack your bits into it's elements. To make this as portable as
> possible, do not assume, say, 8 bits, but use CHAR_BIT defined in
> <limits.h> to tell you the size of `char` on your system. This will be
> more work, so you will lose some performance extracting and packing
> bits, but not too much.[/color]
And use unsigned char, not plain char (which can be either signed or
unsigned).
--
Keith Thompson (The_Other_Keith)
kst-u@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.
