Remove all subtree of Even values node in binary tree

// C Program 
// Remove all subtree of Even values 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;
}
// This is creates and returns the new binary tree node
struct TreeNode *newNode(int data)
{
	// Create dynamic node
	struct TreeNode *new_node = 
      (struct TreeNode *) malloc(sizeof(struct TreeNode));
	if (new_node != NULL)
	{
		//Set data and pointer values
		new_node->data = data;
		new_node->left = NULL;
		new_node->right = NULL;
	}
	else
	{
		//This is indicates, 
		// segmentation fault or memory overflow problem
		printf("Memory Overflow\n");
		exit(0);
	}
	//return new node
	return new_node;
}

struct TreeNode *deleteEvenSubTree(struct TreeNode *node)
{
	if (node != NULL)
	{
		node->left = deleteEvenSubTree(node->left);
		node->right = deleteEvenSubTree(node->right);
		if (node->left == NULL && 
            node->right == NULL &&
            node->data % 2 == 0)
		{
			// free Node
			free(node);
			return NULL;
		}
	}
	return node;
}
int main(int argc, char
	const *argv[])
{
	struct BinaryTree *tree1 = newTree();
	struct BinaryTree *tree2 = newTree();
	/*
	         1                            
	       /   \    
	      2     7    
	     / \     \               
	    6   3     8
	             /  \
	            10   12 
	    ------------
	    Binary tree A
	*/
	// Tree A
	tree1->root = newNode(1);
	tree1->root->left = newNode(2);
	tree1->root->right = newNode(7);
	tree1->root->right->right = newNode(8);
	tree1->root->left->right = newNode(3);
	tree1->root->left->left = newNode(6);
	tree1->root->right->right->left = newNode(10);
	tree1->root->right->right->right = newNode(12);
	/*
	Construct Tree number 2
	---------

	         10                            
	       /   \    
	      2     7    
	     / \     \               
	    6   4     8
	       / \
	      8   20
	    ------------
	    Binary tree B
	*/
	// Tree B
	tree2->root = newNode(10);
	tree2->root->left = newNode(2);
	tree2->root->right = newNode(7);
	tree2->root->right->right = newNode(8);
	tree2->root->left->right = newNode(4);
	tree2->root->left->left = newNode(6);
	tree2->root->left->right->left = newNode(8);
	tree2->root->left->right->right = newNode(20);
	// Test A
	printf("\n Before Delete Tree 1 \n");
	preorder(tree1->root);
	// Remove subtree which contains all Even nodes
	tree1->root = deleteEvenSubTree(tree1->root);
	/*
	         1                            
	       /   \    
	      2     7    
	       \                    
	        3            
	    ------------
	    After delete Even node subtrees
	*/
	printf("\n After Delete Tree 1 \n");
	preorder(tree1->root);
	// Test B
	printf("\n Before Delete Tree 2 \n");
	preorder(tree2->root);
	// Remove subtree which contains all Even nodes
	tree2->root = deleteEvenSubTree(tree2->root);
	/*
	         10                            
	           \    
	            7            
	    ------------
	    After delete Even node subtrees
	*/
	printf("\n After Delete Tree 2 \n");
	preorder(tree2->root);
	return 0;
}

Output

 Before Delete Tree 1
  1  2  6  3  7  8  10  12
 After Delete Tree 1
  1  2  3  7
 Before Delete Tree 2
  10  2  6  4  8  20  7  8
 After Delete Tree 2
  10  7