13.5.1 Starting at the First Node

Finding the smallest node in the tree is just a matter of starting from the root and descending as far to the left as we can.

503. <PBST traverser first initializer 503> =
void *
pbst_t_first (struct pbst_traverser *trav, struct pbst_table *tree) 
{
  assert (tree != NULL && trav != NULL);

  trav->pbst_table = tree;
  trav->pbst_node = tree->pbst_root;
  if (trav->pbst_node != NULL) 
    {
      while (trav->pbst_node->pbst_link[0] != NULL)
        trav->pbst_node = trav->pbst_node->pbst_link[0];
      return trav->pbst_node->pbst_data;
    }
  else 
    return NULL;
}

This code is included in 502 and 546.