问BST二叉树删除函数C值为0的叶子

EN

int delete_zero_leaves (node){
    int deleted
    delete_zero_leaves_aux (node, &deleted);
    return deleted
}

pointer delete_zero_leaves_aux (node, deleted){
    boolean is_leaf = true
    // if there is a child
    if (node->left != NULL){
            // passing deleted by reference
            node->left = delete_zero_leaves_aux (node->left, &deleted)
            is_leaf = false
    }
    // if there is a child on the right side
    if (node->right != NULL){
            // passing deleted by reference
            node->right = delete_zero_leaves_aux (node->right, &deleted)
            is_leaf = false
    }
    if (is_leaf AND node->value == 0){
        free(node)
        deleted += 1
        return NULL
    }
    return node
}