Question

我认为这很容易但我在从文本文件中搜索节点时遇到问题。

文本文件中的数据如下：

1

2

3

4

5

数据存储在字符串“word”中。它们是数字以避免复杂性。

问题是它在调用搜索方法时一直返回false。

public class Search
    {

        static int count;  // number of elements
        Search ()
    {
        count = 0;
    }


    static void inputdata (Node head, Node node) throws IOException
    {
        BufferedReader stdin = new BufferedReader (new InputStreamReader (System.in));
        BufferedReader reader = new BufferedReader (new FileReader ("Words.txt"));

        String word;
        String line = null;


        while ((line = reader.readLine ()) != null)
        {
            word = (line);
            node = new Node (word);
            node.next = head;
            head = node; // need to set the new head of the list to the node that was just inserted
            count++;
        }


        reader.close ();

        node = head;
        System.out.println ("Here is the list:");
        System.out.println ();
        do
        {
            System.out.println (node.data);
            node = node.next;
        }
        while (node != null);
        System.out.println ();
        System.out.println ();
    }




    static boolean Found (String search, Node head, Node node)  // recursive search method
    {
        boolean found;

        Node temp; // sets a termpoary node to the head
        node = head;
        temp = head;

        while (temp != null)
        {
            if (temp.data.equals (search))
                return true;
            temp = temp.next;

        }
        return false;
    }


    public static void main (String str[]) throws IOException
    {
        BufferedReader stdin = new BufferedReader (new InputStreamReader (System.in));
        DecimalFormat df = new DecimalFormat ("#");

        //Search list = new Search (); //calls list via constructor
        Node head = null;
        Node node = null;

        inputdata (head, node);



        System.out.println (count + " entries");

        String search, repeat;


        System.out.println ();
        System.out.println ("Which word do you want to search within the linked list?"); // returns true/false from a method
        search = stdin.readLine ();

        System.out.println (Found (search, head, node));

    }
}

其他文件（类）：

public class Node
{
    Node next, prev;
    String data;

    public Node (String data)
    {
        this.data = data;
    }
}

Answer 1

您的问题是您的链接列表一次只有一个对象，因为您总是将node.next设置为head，并且前往节点。因此，您将始终只打印相同的数字（我将猜测，正是您所看到的）。

您需要做的是修复插入例程。这样的事情应该做（请注意，它是未经测试的）

Node prev;

while((line = reader.readLine()) != null) 
{
    word = line;
    node = new Node(word);
    node.next = null;

    if(head == null) {
        head = node;
    } 

    if(prev != null) {
        prev.next = node;
    }
    prev = node;

}

搜索链表java中的节点时出错？

1 个答案: