AverageDepth

int avgDepth(TreeNode *root)
{
	if(root == NULL)
	{
		return 0;
	}

	if(root->left == NULL && root->right == NULL)
	{
	return 1;
	}

	queue <TreeNode> nodes;
	nodes.push(root);

	queue <int> depth;
	depth.push(1);

	int counter = 1;
	int sum = 0;

	while(!nodes)
	{
		TreeNode *currentNode = nodes.front();
		nodes.pop();
		int currentDistance = depth.front();
		depth.pop();

		if(currentNode->left != NULL)
		{
		nodes.push(currentNode->left);
		depth.push(currentDistance + 1);
		counter++;
		}

		if(currentNode->right != NULL)
		{
		nodes.push(currentNode->right);
		depth.push(currentDistance + 1);
		counter++;
		}
		sum+=currentDistance;
	}

	return ceil(sum/counter);
}