統計unsigned int 二進制1的個數！

unsigned int GetBinaryCount(unsigned int u)   
{   
	u = ((u&0x55555555) + ((u>>1)&0x55555555));   
	u = ((u&0x33333333) + ((u>>2)&0x33333333));   
	u = ((u&0x0f0f0f0f) + ((u>>4)&0x0f0f0f0f));   
	u = ((u&0x00ff00ff) + ((u>>8)&0x00ff00ff));   
	u = ( u&0x0000ffff) + (u>>16);   
	return u;   
}