Find mirror of a given node in binary tree

/*
    C Program 
    Find mirror of a given node in binary tree
*/
#include <stdio.h>
#include <stdlib.h>
// Tree Node
struct TreeNode
{
	int data;
	struct TreeNode *left;
	struct TreeNode *right;
};
// Binary Tree
struct BinaryTree
{
	struct TreeNode *root;
};
// Create new tree
struct BinaryTree *newTree()
{
	// Create dynamic node
	struct BinaryTree *tree = (struct BinaryTree *) malloc(sizeof(struct BinaryTree));
	if (tree != NULL)
	{
		tree->root = NULL;
	}
	else
	{
		printf("Memory Overflow to Create tree Tree\n");
	}
	//return new tree
	return tree;
}
// Returns a new node of tree
struct TreeNode *newNode(int data)
{
	// Create dynamic node
	struct TreeNode *node = (struct TreeNode *) malloc(sizeof(struct TreeNode));
	if (node != NULL)
	{
		//Set data and pointer values
		node->data = data;
		node->left = NULL;
		node->right = NULL;
	}
	else
	{
		//This is indicates, segmentation fault or memory overflow problem
		printf("Memory Overflow\n");
	}
	//return new node
	return node;
}
// Find mirror of given node
struct TreeNode *isMirror(struct TreeNode *node, struct TreeNode *left, struct TreeNode *right)
{
	if (left == NULL || right == NULL)
	{
		// When any subtree are missing
		return NULL;
	}
	if (left == node)
	{
		return right;
	}
	if (right == node)
	{
		return left;
	}
	struct TreeNode *result = isMirror(node, left->left, right->right);
	if (result == NULL)
	{
		result = isMirror(node, left->right, right->left);
	}
	return result;
}
// Handles the request to find mirror of given node
void findMirrorNode(struct TreeNode *root, struct TreeNode *node)
{
	if (root == NULL || node == NULL)
	{
		return;
	}
	struct TreeNode *result = isMirror(node, root->left, root->right);
	printf(" Mirror of node %d is : ", node->data);
	if (result == NULL)
	{
		// When mirror node not found
		printf(" None\n");
	}
	else
	{
		printf(" %d \n", result->data);
	}
}
int main()
{
	// Define tree
	struct BinaryTree *tree = newTree();
	/*
	        -1
	       /   \
	      2     8
	     / \   / \
	    3  -3 6   5
	       /   \   \
	     -7     4  -6
	     /     / \
	    9     1  -2  
	         /
	        7 
	-----------------------
	      Binary Tree
	-----------------------
	*/
	tree->root = newNode(-1);
	tree->root->left = newNode(2);
	tree->root->right = newNode(8);
	tree->root->left->left = newNode(3);
	tree->root->left->right = newNode(-3);
	tree->root->left->right->left = newNode(-7);
	tree->root->left->right->left->left = newNode(9);
	tree->root->right->left = newNode(6);
	tree->root->right->right = newNode(5);
	tree->root->right->left->right = newNode(4);
	tree->root->right->right->right = newNode(-6);
	tree->root->right->left->right->left = newNode(1);
	tree->root->right->left->right->right = newNode(-2);
	tree->root->right->left->right->left->left = newNode(7);
	struct TreeNode *node = tree->root->right->left->right->right;
	findMirrorNode(tree->root, node);
	node = tree->root->left->left;
	findMirrorNode(tree->root, node);
	node = tree->root->right->right->right;
	findMirrorNode(tree->root, node);
	return 0;
}

Output

 Mirror of node -2 is :  9
 Mirror of node 3 is :  5
 Mirror of node -6 is :  None