Thread: Need help with BST Program

Hello All, I'm learning about BST from a book and I'm stuck half way while trying to code a BST. Here's my code:

Code:

#include<stdio.h>
#include<conio.h>
#include<stdlib.h>
typedef struct node
{
        int *dataPtr;
        struct node *left;
        struct node *right;
}NODE;
typedef struct
{
        int count;
        NODE *root;
}TREE;
TREE *createTree(void)
{
     TREE *tree;
     tree = (TREE *)malloc(sizeof(TREE));
     if(tree)
     {
             printf("Tree created successfully. . .\n");
             tree->root = NULL;
             tree->count = 0;
     }
     return tree;
}
void addNode(TREE *tree, int *dataInPtr)
{
    NODE *newNode;
    newNode = (NODE *)malloc(sizeof(NODE));
    if(newNode)
    {
        newNode->dataPtr = dataInPtr;
        newNode->left = NULL;
        newNode->right = NULL;
    }
    if(tree->count == 0)
        tree->root = newNode;
    else
        insertNode(tree->root, newNode, dataInPtr);
    (tree->count)++;
}
NODE *insertNode(NODE *root, NODE *newNode, int *dataInPtr)        
{
    if(!root)
        return newNode;
    if(dataInPtr < root->dataPtr)    
    {
        root->left = insertNode(root->left, newNode, dataInPtr);
        return root;
    }
    else
    {
        root->right = insertNode(root->right, newNode, dataInPtr);
        return root;
    }
    return root;
}
void inOrder(NODE *node)
{
     if(node != NULL)
     {
             inOrder(node->left);
             printf("%d\t", node->dataPtr);
             inOrder(node->right);
     }
}
int main(void)
{
    TREE *tree;
    tree = createTree();
    addNode(tree->root, 20);
    inOrder(tree->root);
    getch();
    return 0;
}

I kinda know where the problem lies. In the "else" loop of the addNode() function, I call insertNode() function which is a function with a void return type. But the insertNode() function actually return a NODE type.

I really don't know how to set the left and right nodes. I tried several things but failed. I want to do it on my own. Any help / suggestion would be appreciated.

Thanks in advance.