void show_tree_inorder()
{
    if(root != NULL)
    {
        show_node_inorder(root);
    }

}

void show_node_inorder(students* node)
{
    if (node->left != NULL)
    {
        show_node_inorder(node->left);
    }
    printf("%i \n", node->id);
    if (node->right != NULL)
    {
        show_node_inorder(node->right);
    }
}