Binary tree creation and in-order printing.

binary_tree.c

#include <stdio.h>
#include <malloc.h>

typedef struct _node
{
  int data;
	struct _node *left;
	struct _node *right;
}node;

node * add_node(node *node_ptr, int data)
{
	if(node_ptr)	
	{
		printf("Already memory allocated, possible memory leak\n");
		
	}
	else
	{
		node_ptr = (node *)malloc(sizeof(node));
		if(!node_ptr)
		{
			printf("error\n");
			return NULL;
		}
	}
	
//	printf("Adding new node \n");	
	node_ptr->data = data;
	node_ptr->left = node_ptr->right = NULL;
	return node_ptr;
}

int add_node_bintree(node **root,int data)
{
	if(!*root)
	{ //1st element in tree. 
		printf("Added node in head\n");
		*root=add_node(*root, data);
		if(!root)
		{
			printf("Error \n");
		}
	}
	else if(data < (*root)->data)
	{
		printf("adding node to left\n");
		if(!(*root)->left)
		{
			(*root)->left = add_node((*root)->left,data);	
		}
		else
		{
			add_node_bintree(&((*root)->left), data);
		}
	}
	else
	{
		printf("adding node to right\n");
		if(!(*root)->right)
		{
			(*root)->right = add_node((*root)->right, data);
		}
		else
		{
			add_node_bintree(&((*root)->right), data);
		}
	}

}

void print_bintree(node *root)
{
	if(!root)
		return;

	print_bintree(root->left);
	printf(" %d -> ",root->data);
	print_bintree(root->right);
}

int main()
{
	int array[10]={5,6,42,12,3,80,12,13,10,11};
	int i=0;
	node *root = NULL;
	
	for(i=0; i < 10; i++)
	{
		printf("adding data to tree %d \n",array[i]);
		add_node_bintree(&root,array[i]);
	}

	printf("Data in tree \n Printing data\n");

	print_bintree(root);
	printf(" NULL \n");
	
}