Question

你好，所以我无法完成我的任务，因为我很难弄清楚如何在我的链表中设置搜索方法。现在我仍然想学习如何配置链表，我不能完成任何一个其他方法，如删除，或替换，如果我不能找出搜索方法。出于某种原因，我的结果一直是空的。这就是我到目前为止所拥有的......

public class WordList {
private WordMeaningNode list;
WordList()
{
    list = null;
}
void add(WordMeaning b)
{
    WordMeaningNode temp = new WordMeaningNode(b);
    try
    {
        temp.Next = list;
        list = temp;
    }
    catch(NullPointerException e)
    {
        System.out.println("Null Pointer Exception");
    }
}
public String toString()
{
    String result="";
    WordMeaningNode current = list;
    while (current != null)
    {
        result += current.Words.word + " - " + current.Words.meaning + "\n";
        current = current.Next;
    }
    return result;
}
public WordMeaning findword (WordMeaning Word)
{

    WordMeaningNode Checker = new WordMeaningNode(Word);

    boolean found = false;

    if (list.isEmpty() == true)
    {
        return null;
    }
    else
    {
        while(list.Next != null && !found)
        {
            if(list.Words.word.compareTo(Checker.Words.word)== 0)
            {
                found = true;
            }
            else
            {
                list = list.Next;
                found = false;
            }
        }
    }
    if(found == true)
    {
        return list.Words;
    }
    else
    {
        return null;
    }
}

Answer 1

您的版本实际上会在每次破坏列表的迭代中更改list（实际上是列表的根（或第一个）节点）。您的查询方法不应更改列表本身。只需在while循环中使用临时（本地）节点变量（我的名为current），如下所示：

public WordMeaning findWord (WordMeaning word)
{
    if (list.isEmpty())
    {
        return null;
    }

    boolean found = false;
    WordMeaningNode current = list;
    while(current != null)
    {
        if(current.Words.word.compareTo(word)== 0)
        {
            found = true;
            break;
        }
        current = current.Next;
    }
    return current;
}

Answer 2

这是如何在链表中查找元素的示例：

public class LinkedList<T> {

    private LinkedList<T> next;
    private T data;

    public LinkedList(T value) {
        data = value;
    }

    public LinkedList<T> next() {
        return next;
    }

    public T value() {
        return data;
    }

    public void setNext(LinkedList<T> element) {
        next = element;
    }

    public void setValue(T value) {
        data = value;
    }
}

public LinkedList<Integer> find(LinkedList<Integer> head, int data) {
    LinkedList<Integer> elem = head;
    while (elem != null && elem.value() != data) {
        elem = elem.next();
    }
    return elem;
}

Java链表清单搜索方法

2 个答案: