Method print_node

publication/code/chapter09/bfs.rs:48–56

打印节点

(&self)

    // 打印节点
    fn print_node(&self) {
        let mut curr = self.first.clone();
        while let Some(val) = curr {
            print!("[{}]", &val.borrow().data);
            curr = val.borrow().next.clone();
        }

        print!("\n");
    }

    // 插入节点，RefCell 使用 borrow_mut 修改
    fn insert(&mut self, data: usize) {