#include <stdio.h>
#include <stdlib.h>
#include "bin-trees.h"
static void
real_preorder (tree_ptr root)
{
if (root == NULL)
return;
printf ("%d ", root->data);
real_preorder (root->left);
real_preorder (root->right);
}
void
pre_order_traverse (tree_ptr root)
{
printf ("pre-order traversal, with recursion: \n");
real_preorder (root) ;
printf ("\n");
}