数据结构-双链表

来源：互联网发布：伴奏提取软件编辑：程序博客网时间：2024/05/16 14:49

http://www.cnblogs.com/skywang12345/p/3561803.html

public class DoubleLink<T>{
   private DNode<T> mHead;
   private int mCount;

   class DNode<T>{
       private DNode prev;
       private DNode next;
       private T value;

       public DNode(T value,DNode prev,DNode next){
           this.value = value;
           this.prev = prev;
           this.next = next;
       }
   }

   public DoubleLink(){
       mHead = new DNode<T>(null, null, null);
       mHead.prev = mHead.next = mHead;
       mCount = 0;
   }

   public int size(){
       return mCount;
   }

   public boolean isEmpty(){

       return mCount == 0;
   }


   private DNode<T> getNode(int index){
       if(index < 0 || index >= mCount){
           throw new ArrayIndexOutOfBoundsException();
       }
       if(index <= mCount/2){
           DNode<T> node = mHead.next;
           for(int i = 0;i < index; i++){
               node = node.next;
           }
           System.out.println("t1:" +node.prev.value + " " + node.value+" " + node.next.value);
           return node;
       }

       DNode<T> prveNode = mHead.prev;
       int pIndex = mCount -index -1;
       for(int i= 0;i < pIndex;i++){
           prveNode = prveNode.prev;
       }
       System.out.println("t2:" +prveNode.prev.value + " " + prveNode.value+" " + prveNode.next.value);
       return prveNode;
   }


   public DNode<T> get(int index){
       return getNode(index);
   }

   public T getFirst(){
       return getNode(0).value;

   }

   public T getLast(){
       if(isEmpty()){
           throw new ArrayIndexOutOfBoundsException();
       }
       return getNode(mCount-1).value;
   }

   /**
   * 在之前插入
   * @param index
   * @param value
   */
   public void insert(int index,T value){
       if(index == 0){
           DNode<T> dnt = new DNode<T>(value, mHead, mHead.next);
           mHead.next.prev = dnt;
           mHead.next = dnt;
           mCount++;
           return;
       }
       DNode<T> dnt= getNode(index);

       DNode<T> pDnt = new DNode<T>(value,dnt.prev,dnt);

       dnt.prev.next =pDnt;

       dnt.prev =pDnt;
       mCount++;
       return;
   }

   public void insertFirst(T value){
       insert(0, value);   }

   public void append(T value){
       if(isEmpty()){
           insertFirst(value);
       }else{
           DNode<T> lastNode = getNode(mCount -1);
           DNode<T> node = new DNode<T>(value,lastNode,lastNode.next);
           lastNode.next.prev = node;
           lastNode.next = node;
           mCount++;
           //lastNode.next.prev = node;
       }

   }

   public void del(int index){
       DNode<T> node = getNode(index);
       node.prev.next = node.next;
       node.next.prev = node.prev;
       node = null;
       mCount --;
       return;
   }

   public void delFirst(){
       del(0);
   }
   public void delLast(){
       del(mCount -1);
   }

   public static void main(String[] args) {
       DoubleLink<Integer> dlink = new DoubleLink<Integer>();

       dlink.insertFirst(30);
       dlink.insert(0,20);
       dlink.insert(0,10);
       dlink.insert(1, 15);

       dlink.insert(3, 25);
       dlink.append(40);
       dlink.append(50);

       dlink.del(1);

       for (int i=0; i<dlink.size(); i++){
           System.out.println("dlink("+i+")="+ dlink.get(i).value);
       }
   }
}

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