SLinkedList und Knoten in Java

Mit zu beginnen, ja, das ist für eine Zuordnung in die Klasse, aber mein Mangel an Verständnis, wie es funktioniert, ist höher, als ich es will.

Erhielten wir 3 Klassen, Sie sind die folgenden:

SLinkedList.java

package chapter3.linkedList;

public class SLinkedList<V> {
    //instance variables.  Add the tail reference.
    protected Node<V> head, tail;
    protected long size;

    //methods, empty list constructor first
    public SLinkedList () {
        head = null;
        tail = null;
        size = 0;
    }  //end constructor of a SLinkedList

    //method to add nodes to the list.  Storage space for the node
    //is already allocated in the calling method
    public void addFirst (Node<V> node) {
        //set the tail only if this is the very first node
        if (tail == null)
            tail = node;
        node.setNext (head);    //make next of the new node refer to the head
        head = node;            //give head a new value

        //change our size
        size++;
    }  //end method addFirst

    //addAfter - add new node after current node, checking to see if we are at the tail
    public void addAfter (Node<V>currentNode, Node<V>newNode) {
        if (currentNode == tail)
            tail = newNode;
        newNode.setNext (currentNode.getNext ());
        currentNode.setNext (newNode);

        //change our size
        size++;
    }  //end method addAfter

    //addLast - add new node after the tail node.  Adapted from Code Fragment 3.15, p. 118.
    //Mike Qualls
    public void addLast (Node<V> node) {
        node.setNext (null);
        tail.setNext (node);
        tail = node;
        size++;     
    }  //end method addLast

    //methods to remove nodes from the list.  (Unfortunately, with a single linked list
    //there is no way to remove last.  Need a previous reference to do that.  (See
    //Double Linked Lists and the code below.)
    public Node<V> removeFirst () {
        if (head == null)
            System.err.println("Error:  Attempt to remove from an empty list");

        //save the one to return
        Node<V> temp = head;

        //do reference manipulation
        head = head.getNext ();
        temp.setNext(null);
        size--;

        return temp;

    }  //end method removeFirst

    //remove the node at the end of the list.  tail refers to this node, but
    //since the list is single linked, there is no way to refer to the node
    //before the tail node.  Need to traverse the list.
    public Node<V> removeLast () {
        ////declare local variables/objects
        Node<V> nodeBefore;
        Node<V> nodeToRemove;

        //make sure we have something to remove
        if (size == 0)
            System.err.println("Error:  Attempt to remove fron an empty list");

        //traverse through the list, getting a reference to the node before
        //the trailer.  Since there is no previous reference.
        nodeBefore = getFirst ();

        //potential error  ??  See an analysis and drawing that indicates the number of iterations
        //9/21/10.  size - 2 to account for the head and tail nodes.  We want to refer to the one before the
        //tail.
        for (int count = 0; count < size - 2; count++)
            nodeBefore = nodeBefore.getNext ();

        //save the last node
        nodeToRemove = tail;

        //now, do the pointer manipulation
        nodeBefore.setNext (null);
        tail = nodeBefore;
        size--;

        return nodeToRemove;

    }  //end method removeLast

    //method remove.  Remove a known node from the list.  No need to search or return a value.  This method
    //makes use of a 'before' reference in order to allow list manipulation.
    public void remove (Node<V> nodeToRemove) {
        //declare local variables/references
        Node<V> nodeBefore, currentNode;

        //make sure we have something to remove
        if (size == 0)
            System.err.println("Error:  Attempt to remove fron an empty list");

        //starting at the beginning check for removal
        currentNode = getFirst ();
        if (currentNode == nodeToRemove)
            removeFirst ();
        currentNode = getLast ();
        if (currentNode == nodeToRemove)
            removeLast ();

        //we've already check two nodes, check the rest
        if (size - 2 > 0) {
            nodeBefore = getFirst ();
            currentNode = getFirst ().getNext ();
            for (int count = 0; count < size - 2; count++) {
                if (currentNode == nodeToRemove) {
                    //remove current node
                    nodeBefore.setNext (currentNode.getNext ());
                    size--;
                    break;
                }  //end if node found

                //change references
                nodeBefore = currentNode;
                currentNode = currentNode.getNext ();
            }  //end loop to process elements
        }  //end if size - 2 > 0

    }  //end method remove

    //the gets to return the head and/or tail nodes and size of the list
    public Node<V> getFirst () { return head; }
    public Node<V> getLast () { return tail; }  
    public long getSize () { return size; }

}  //end class SLinkedList

Node.java

Paket chapter3.linkedList;

public class Node<V> {
    //instance variables
    private V element;
    private Node<V> next;

    //methods, constructor first
    public Node () {
        this (null, null);      //call the constructor with two args
    }  //end no argument constructor
    public Node (V element, Node<V> next) {
        this.element = element;
        this.next = next;
    }  //end constructor with arguments

    //set/get methods
    public V getElement () { return element; }
    public Node<V> getNext () { return next; }
    public void setElement (V element) { this.element = element; }
    public void setNext (Node<V> next) { this.next = next; }

}  //end class Node

und GameEntry.java

package Project_1;

public class GameEntry 
{
    protected String name;  //name of the person earning this score
    protected int score;    //the score value
    /** Constructor to create a game entry */
    public GameEntry(String name, int score) 
    {
      this.name = name;
      this.score = score;
    }
    /** Retrieves the name field */
    public String getName() 
    { 
        return name; 
    }
    /** Retrieves the score field */
    public int getScore() 
    { 
        return score; 
    }
    /** Returns a string representation of this entry */
    public String toString() 
    { 
      return "(" + name + ", " + score + ")"; 
    }

}

Ich habe in den letzten 3 Stunden Zuhören zu seinem Vortrag, Lesung durch den text (Datenstrukturen und Algorithmen 5. Auflage), und suchen durch internet-Foren und youtube-videos, aber ich kann nicht scheinen zu begreifen, zu verstehen, wie er den Knoten/slinkedlist Klasse.

Gegenstand der Abtretung ist "Schreiben Sie eine Klasse, die behauptet, die top 10 erreicht souverän oder ein Spiel-Anwendung, die Implementierung der add-und remove-Methoden, sondern mithilfe einer einfach verkettete Liste statt einem array.

Ich nicht wollen, dass jemand das für mich tun, ich will aber wissen, wie man die verlinkte Liste. Ich weiß diese sind NICHT so schwer, aber tun Sie mit diesem code, den er gegeben hat, schmerzhaft schwer, jede Hilfe wäre wirklich zu schätzen.

Vielen Dank im Voraus.

Edit:

Meine main-Funktion: ScoresTest.java

package Project_1;

public class ScoresTest {

    /**
     * @param args
     */
    public static void main(String[] args) 
    {
          GameEntry entry;
          Scores highScores = new Scores();     
          entry = new GameEntry("Anna", 600);       
          highScores.add(entry);
          entry = new GameEntry("Paul", 720);
          highScores.add(entry); 
          System.out.println("The Original High Scores");
          System.out.println(highScores);

          entry = new GameEntry("Jill", 1150);
          highScores.add(entry);
          System.out.println("Scores after adding Jill");
          System.out.println(highScores);
    }

}

Dies ist zum größten Teil genau so sollte es am Ende der Suche, aber es ist alles, dass macht diese Arbeit, werfe mich Weg...naja...alles was den Umgang mit den 3 Klassen, die oben erwähnten, konnte ich dies tun, wenn Sie waren nicht ein Faktor, ohne zu viel von einem Problem, Sie sind das, was verursacht meine leere.

InformationsquelleAutor Soully | 2011-09-13