typedef struct bitmap_element_def
{
  struct bitmap_element_def *next;               
  struct bitmap_element_def *prev;               
  unsigned int indx;                     
  unsigned int  bits[2 ];  
} bitmap_element;

 
typedef struct bitmap_head_def {
  bitmap_element *first;         
  bitmap_element *current;       
  int indx;                      
} bitmap_head, *bitmap;