/**
 * @brief del_node -- Функция удаления элемента по ключу из дерева
 * @param root -- Корень дерева
 * @param deleting -- Удаляемый узел
 * @return Указатель на корень
 */
tree *del_node(tree *root, tree *deleting)
{
    tree *pre_del = find_walk_addr(root, deleting);

    if ((deleting->left == NULL) && (deleting->right) == NULL)
    {
        if (deleting == pre_del->left)
        {
            free(deleting);
            pre_del->left = NULL;
        }
        else
        {
            free(deleting);
            pre_del->right = NULL;
        }
        return root;
    }
    else if ((deleting->left != NULL) && (deleting->right == NULL))
    {
        if (deleting == pre_del->left)
        {
            pre_del->left = deleting->left;
            free(deleting);
        }
        else
        {
            pre_del->right = deleting->left;
            free(deleting);
        }
        return root;
    }
    else if ((deleting->right != NULL) && (deleting->left == NULL))
    {
        if (deleting == pre_del->left)
        {
            pre_del->left = deleting->right;
            free(deleting);
        }
        else
        {
            pre_del->right = deleting->right;
            free(deleting);
        }
        return root;
    }
    else if ((deleting->right != NULL) && (deleting->left != NULL))
    {
        tree *tmp = deleting;
        for (; tmp->left->left; tmp = tmp->left)
        {;}

        deleting->key = tmp->left->key;
        strcpy(deleting->str, tmp->left->str);
        free(tmp->left);
        tmp->left = NULL;
        return root;
    }

    return root;
}