Question

所以我目前正在尝试创建一个圆链表（双链表，每个值都有一个前一个，下一个值不等于null），我不确定我是否正确创建它。我的目标是能够创建一个LinkedList值，然后当我遍历列表时，hasNext（）应该总是返回true（没有空值）。我认为我添加价值的方式有问题，但我不确定。这是代码，CircularList类有一个内部节点类：

public class CircularList<E> {
//I decided to still have heads and tails, to link them together
private Node<E> first = null;
private Node<E> last = null;
private Node<E> temp;
private int size;

//inner node class
private static class Node<E>{ //In this case I am using String nodes
    private E data; //matching the example in the book, this is the data of the node
    private Node<E> next; //next value
    private Node<E> prev; //previous value
    //Node constructors, also since in this case this is a circular linked list there should be no null values for previous and next    
    private Node(E data, Node<E> next, Node<E> prev){
        this.data = data;
        this.next = next;
        this.prev = prev;
    }
}
//end of inner node class
public void addValue(E item){
    Node<E> n = new Node<E>(item, first, last);
    if(emptyList() == true){ //if the list is empty
        //only one value in the list
        first = n;
        last = n;
    }
    else{ //if the list has at least one value already
        temp = first;
        first = n;
        first.next = temp;
        last.next = first;
    }
    size++;
}

public boolean emptyList(){
    boolean result = false;
    if(first == null && last == null){ //if there is no values at all
        result = true;
    }
    return result;
}
}

Answer 1

刚刚进行了快速扫描，但这就是它出错的地方：

Node<E> n = new Node<E>(item, first, last);
if(emptyList() == true) {
    //if the list is empty
    //only one value in the list
    first = n;
    last = n;
}

此节点内的prev和next项目仍为null。你也应该设置它们。

else {
    //if the list has at least one value already
    temp = first;
    first = n;
    first.next = temp;
    last.next = first;
}

此外，您不会在此处更新prev。

还要考虑在内部使用链表作为后备数据结构，而不是您自己的节点结构。然后你只需要创建循环迭代器。

我的Circular LinkedList会正常工作吗？

1 个答案: