node_t *insert_node(node_t *root, node_t *new)
{
    node_t** curr = &root;
    while (*curr)
    {
        if (strcmp(new->name, (*curr)->name) < 0)
            curr = &(*curr)->left;
        else curr = &(*curr)->right;
    }

    *curr = new;
    return root;
}