Print all palindromic levels of a binary tree

// C program
// Print all palindromic levels of a binary tree
#include <stdio.h>

#include <stdlib.h>

//Node of binary tree
struct Node
{
	int data;
	struct Node *left, *right;
};
struct MyQueue
{
	int level;
	struct Node *element;
	struct MyQueue *next;
};
//Create a binary tree nodes and node fields (data,pointer) 
//And returning the reference of newly nodes
struct Node *insert(int data)
{
	//create dynamic memory to new binary tree node
	struct Node *new_node = (struct Node *) malloc(sizeof(struct Node));
	if (new_node != NULL)
	{
		//Set node value
		new_node->data = data;
		new_node->left = NULL;
		new_node->right = NULL;
	}
	else
	{
		printf("Memory Overflow\n");
	}
	//return reference
	return new_node;
}
//Create a queue node and returns this node
struct MyQueue *enqueue(struct Node *tree_node)
{
	//Make a new Queue node
	struct MyQueue *new_node = (struct MyQueue *) malloc(sizeof(struct MyQueue));
	if (new_node != NULL)
	{
		//Set node values
		new_node->element = tree_node;
		new_node->next = NULL;
	}
	else
	{
		printf("Memory Overflow\n");
	}
	return new_node;
}
//Remove a queue elements
void dequeue(struct MyQueue **front)
{
	if ( *front != NULL)
	{
		struct MyQueue *remove = *front;
		//Visit to next node
		*front = remove->next;
		remove->element = NULL;
		remove->next = NULL;
		//free node
		free(remove);
		remove = NULL;
	}
}
int is_palindrome(struct MyQueue *front, int level)
{
	if (front == NULL)
	{
		return 0;
	}
	int size = 0;
	struct MyQueue *temp = front;
	//Count number of nodes in given level
	while (temp != NULL && temp->level == level)
	{
		size++;
		temp = temp->next;
	}
	if (size == 1)
	{
		//When only one element in given level
		return 1;
	}
	else
	{
		int collection[size];
		int first = 0;
		int last = size - 1;
		temp = front;
		//Get the nodes of given level
		while (temp != NULL && temp->level == level)
		{
			// Get node value
			collection[first] = temp->element->data;
			temp = temp->next;
			// Change location
			first++;
		}
		first = 0;
		//Determine whether collection contains palindrome or not
		while (first < last)
		{
			if (collection[first] != collection[last])
			{
				return 0;
			}
			first++;
			last--;
		}
		//When palindrom exist
		return 1;
	}
}
//print all palindrom level nodes in binary tree
void palindrome_level(struct Node *root)
{
	if (root != NULL)
	{
		//make a queue pointers
		struct MyQueue *front = NULL, *tail = NULL;
		struct MyQueue *temp = NULL;
		//Get first node of tree
		front = enqueue(root);
		//Start level of first node is one
		front->level = 1;
		//Set tail node to first node
		tail = front;
		struct Node *node = root;
		// Start to first node
		temp = front;
		// Get level elements into a queue
		while (temp != NULL)
		{
			//Tree node
			node = temp->element;
			if (node->left != NULL)
			{
				//Add new left child node
				tail->next = enqueue(node->left);
				tail->next->level = temp->level + 1;
				tail = tail->next;
			}
			if (node->right != NULL)
			{
				//Add new right child node
				tail->next = enqueue(node->right);
				tail->next->level = temp->level + 1;
				tail = tail->next;
			}
			//Visit to next node queue
			temp = temp->next;
		}
		//result node indicator
		int status = 0;
		int level = 0;
		while (front != NULL)
		{
			level = front->level;
			status = is_palindrome(front, level);
			if (status == 1)
			{
				printf(" [");
			}
			// When level nodes are palindromic, 
			// Then this loop are printed node value and remove level nodes
			// Otherwise it's removing current level nodes
			while (front != NULL && front->level == level)
			{
				if (status == 1)
				{
					//When palindromic exist
					printf(" %d", front->element->data);
				}
				//remove  a queue node
				dequeue( &front);
			}
			if (status == 1)
			{
				printf(" ]\n");
			}
		}
		tail = NULL;
	}
	else
	{
		printf("Empty Tree\n");
	}
}
int main()
{
	struct Node *root = NULL;
	/*
	Construct Binary Tree
	-----------------------
	           10
	         /   \
	        2     3
	       /     / \
	      4     9   4
	     /  \    \    \
	    7    3    6   11
	        /  \     /
	       2    8   2
	           / \    
	         -1   -1

	-----------------------
	*/
	//Add node
	root = insert(10);
	root->left = insert(2);
	root->right = insert(3);
	root->right->right = insert(4);
	root->right->left = insert(9);
	root->left->left = insert(4);
	root->left->left->left = insert(7);
	root->left->left->right = insert(3);
	root->right->left->right = insert(6);
	root->right->right->right = insert(11);
	root->right->right->right->left = insert(2);
	root->left->left->right->left = insert(2);
	root->left->left->right->right = insert(8);
	root->left->left->right->right->left = insert(-1);
	root->left->left->right->right->right = insert(-1);
	palindrome_level(root);
	return 0;
}

Output

 [ 10 ]
 [ 4 9 4 ]
 [ 2 8 2 ]
 [ -1 -1 ]