_LETTERS TO THE EDITOR_

Example 1: by Richard Zigler

typedef struct
     {
     int       cnt           ;    /* count of nodes to root     */
     DWORD     path          ;    /* bit-encoded path to root   */
     }         HPATH         ;    /* path to root of Huffman tree */
static int pascal compress ( void )
     {
     register int  c         ;    /* chars from input file  */
                   h         ;    /* follows path through tree */
     int           ncnt      ;    /* count nodes to root         */
                   child     ;    /* child node of current node */
     HPATH       * php       ;    /* pointer to HPATH array     */
     DWORD         acc  = OL ;    /* accumulator for code bits  */
for  ( c = 0 ; < 256 ; c++ )
     {
     if  ( ht[c].cnt > 0 )
         {
         php    = hp  + c;
         h      = c;
         ncnt   = 0;
         acc    = OL;
         do
             {
             ncnt++;
             acc   <<= 1;
             child   = h;
             h = ht[h].parent;
             if  ( child == ht[h].left )
                 (int)acc  |= 1;
             }
           while( ht[h].parent  != -1 );
           php->cnt  = ncnt;
           php->path = acc;
           }
     }
     while  (  (c = getc(fi))  != EOF  )
       {
       php     = hp  +  c:
       ncnt    = php->cnt;
       acc     = php->path;
       while   (  ncnt--  )
          {
          outbit (  (int)acc  &  1  );
          acc  >>=  1;
          }
     }
}