Prev: Function param expects IEnumerable<ClassName>
Next: Lambda Expression
From: david jacques on 21 Sep 2009 10:34
Hi there,

How did you come up with the values:
0xe994
14
3

in the CountBits(int value) method.

They are hard coded and dont have any equation that can explain it.

If you can that would be excellent :)

*** Sent via Developersdex http://www.developersdex.com ***
From: Göran Andersson on 23 Sep 2009 08:56
david jacques wrote:
> Hi there,
>
> How did you come up with the values:
> 0xe994
> 14
> 3
>
> in the CountBits(int value) method.
>
> They are hard coded and dont have any equation that can explain it.
>
> If you can that would be excellent :)

The value 0xe994 is just a bit mask:

11 01 10 01 10 01 01 00

Each two bits represent the number of bits in a three bit value. The
method chops the value up in three bit chunks and adds up the number of
bits in each chunk.

14 is 7 times 2, i.e. the three lower bits multiplied by 2 to get an
index to a pair of bits in the bit mask.

--
G�ran Andersson
_____
http://www.guffa.com
 | 
Pages: 1
Prev: Function param expects IEnumerable<ClassName>
Next: Lambda Expression