Thread: counting nodes BST

How do I count the nodes? i have got so far :

Code:

#include <stdio.h>

#include <stdlib.h>

#include <assert.h>



typedef int data_t;		/* For a tree of ints */

#include "treeops.c"



int

main ()

{

	int value, size=0;

	tree_t *tree;

	node_t *result;

	tree = make_empty_tree ();





/** your experimentatation code goes here **/

	printf("Enter some value onto a tree for testing: ");

	while (scanf("%d", &value)!=EOF)

	{

		tree = insert_in_order (tree, value);	

	}

	size = tree_size(tree);

	

	printf("The size of the tree is: ");

	printf("%d", size);

	

    /** Clean up the mess **/

	free_tree (tree);

	tree = NULL;



    /** Exit gracefully **/

	return (EXIT_SUCCESS);

}


int 

tree_size(tree_t *tree) {

	node_t *ptr;

	ptr = tree->root;

	return num_nodes(ptr);

}



int

num_nodes(node_t *root) {

	if (root==NULL)

	{

		return 0;

	}

	else 

	{

		return (1 + num_nodes(root->left) + num_nodes(root->right));		

	}

}




tree_t

*insert_in_order (tree_t *tree, data_t value)

{

	/* make new node */

	node_t *new;

	new = malloc (sizeof (node_t));

	assert (tree!=NULL && new!=NULL);

	new->data = value;

	new->left = NULL;

	new->right = NULL;

	/* insert node in tree */

	tree->root = recursive_insert (tree->root, new);

	return tree;

}

Is there a better way to write tree_size to not include num_nodes. I find tree_size hard to deal with because it is passed a tree_t pointer, not a node_t and so cant recurse

my bad, it does work, but i was inserting the same number into the tree.... is there an iterative method to count the nodes? I understand that recursion is specifiically for BST's, but there must be a method to do it iterativly...