Question

我的程序用于获取单词列表，并按字母序列中的字母引用按升序存储每个单词。例如A-Z字的数组apple，A下的Ape引用的A下的Ape，Z引用的Z下的Zebra 25.但是当我使用标准first = new Node（word）时我没有添加任何内容。我绝望地失去了。

import java.util.LinkedList;
public class ArrayLinkedList 
{    
   /**
    The Node class is used to implement the 
    linked list.
   */

   private class Node
   {
      String value;
      Node next;

      /**
       * Constructor
       * @param val The element to store in the node
       * @param n The reference to the successor node
       */
      Node(String val, Node n)
      {
         value = val; 
         next = n;
      }
      Node(String val)
      {
          this(val, null);
      }
    }     

    private final int MAX = 26; // Number of nodes for letters
    private Node first;         // List head
    private Node last;          // Last element in the list
    private LinkedList[] alpha; // Linked list of letter references

    /**
    * Constructor to construct empty array list
    */

    public ArrayLinkedList()
    {
        first = null;
        last = null;
        alpha = new LinkedList[MAX];

        for (int i = 0; i < MAX; i++)
        {
            alpha[i] = new LinkedList();
        }
    }

    /**
     * arrayIsEmpty method
     * To check if a specified element is empty
     */
    public boolean arrayIsEmpty(int index)
    {
        return (alpha[index].size() == 0);  
    }

    /**
     * The size method returns the length of the list
     * @return The number of elements in the list
     */
     public int size() 
     {
          int count = 0;
          Node p = first;
          while (p != null)
          {
              // There is an element at p
              count++;
              p = p.next;
          }
          return count;
     }    

    /**
     * add method
     * Adds the word to the first position in the linked list
     */
    public void add(String e)
    {
        String word = e.toLowerCase();  // Put String to lowercase
        char c = word.charAt(0);        // to get first letter of string
        int number = c - 'a';           // Index value of letter

        // Find position of word and add it to list
        if (arrayIsEmpty(number)) 
        {
            first = new Node(word);
            first = last;
        }
        else
        {
            first = sort(first, word, number);
        }     
    }

    /**
     * nodeSort method
     * To sort lists
     */
    private Node sort(Node node, String value, int number) {
        if (node == null) // End of list
        { 
            return getNode(value, number);
        }
        int comparison = node.value.compareTo(value);
        if (comparison >= 0)  // Or > 0 for stable sort.
        {
            Node newNode = getNode(value, number); // Insert in front.
            newNode.next = node;
            return newNode;
        }
        node.next = sort(node.next, value, number); // Insert in the rest.
        return node;
}

    private Node getNode(String value, int number) 
    {
        return first.next;
    }
    /**
     * get method
     * to get each word value from the linked list and return it
     * @return value
     */

    public LinkedList get(int index)
    {
        return alpha[index];
    }

    public String toString()
    {
        StringBuilder sBuilder = new StringBuilder();

        sBuilder.append("Word and occurrence in ascending order\n\n");

        Node p = first;

        while (p != null)
        {
            sBuilder.append(p.value + "\n");            
            p = p.next;
        }
        return sBuilder.toString();     
    }
}

Answer 1

你是否有这样做的原因。我可以想到一个更简单的方法：使用Map将一个字符（例如“A”）映射到一个LinkedList of Words。

创建链接列表数组

1 个答案: