java中的循環鏈表問題

Question

嗨我的循環鏈表類遇到問題。即時通訊假設有一個循環鏈接的類，通過一定數量的元素運行。當它到達列表的末尾時，它會一直移動到列表的開頭，並開始進行各種類型的循環。以及我的問題是我不能讓我的名單循環與我已經做出的方法。即時通訊假設有一個方法，將元素添加到列表的末尾以及將它們設置到列表的前面的方法。以及我的前臺不能正常工作，所以我想我發佈，看看是否有任何代碼的幫助。我也想運行一個字符串循環，比如我想創建一個循環鏈表，從週六開始到週六結束，然後將星期六和星期日連接起來，然後循環遍歷每一個循環，任何人都可以告訴我如何在測試我的代碼時做到這一點。

我的輸出出來像

應該打印1 2 3 4 1 2 3 4 1 2 3
應該打印3 4 1 2 3 4 1 2 3 4 1
應打印3 4 1 2 -1 3 4 1 2 -1 3
3 1 2 3 4 -1 3 1 2 3 4
應打印3 1 2 -1 3 1 2 -1 3 1 2
3 1 2 3 -1 3 1 2 3 -1 3

代碼：

public class LinkedListIterator<T> implements Iterator<T> { 
private PublicNode<T>first; 
private PublicNode<T>current; 

    public LinkedListIterator(PublicNode<T> first){ 
     this.first =first; 
     current = first; 
    } 
    public boolean hasNext() { 
     return current!=null; 
    } 
    public T next() { 
     if(!hasNext()){ 
      throw new NoSuchElementException(); 
     } 
     T result = current.getElement(); 
     current = current.getNext(); 
     return result; 
    } 

    public void remove() throws UnsupportedOperationException { 
     throw new UnsupportedOperationException(); 
    } 
    public void setFirst(PublicNode<T> first) { 
     this.first = first; 
    } 
    public PublicNode<T> getFirst() { 
     return first; 
    } 

} 

而且

public class CircularLinkedList<T> implements CircularList<T> { 
    private PublicNode<T> head; 
    private PublicNode<T> tail; 
    private int size; 


    public CircularLinkedList() { 
     head = null; 
     tail = null; 
     size = 0; 
    } 
    //bigO(1) 
    public PublicNode<T> getHead() { 
     return head; 
    } 
    //bigO(1) 
    public void setHead(PublicNode<T> head) { 
     this.head = head; 
    } 
    //bigO(1) 
    public PublicNode<T> getTail() { 
     return tail; 
    } 
    //bigO(1) 
    public void setTail(PublicNode<T> tail) { 
     this.tail = tail; 
    } 
    //bigO(1) 
    public int getSize() { 
     return size; 
    } 
    //bigO(1) 
    public void setSize(int count) { 
     this.size = count; 
    } 
    //bigO(1) 
    public boolean isEmpty() { 
     return tail == null || head == null; 
    } 

    // add element to the end of the list 
    public void addLast(T element) { 
     PublicNode<T> node = new PublicNode<T>(element); 
     if(this.tail==null){ 
      node.setNext(null); 
      node.setPrevious(null); 
      this.tail=node; 
     }else{ 
      PublicNode<T> oldTail = this.tail; 
      oldTail.setNext(node); 
      node.setNext(head); 
      node.setPrevious(oldTail); 
      this.tail =node; 
     }if(this.head==null){ 
      this.head=node; 
     } 
     this.size++; 
    } 

      // set element to be front of the list 
    //bigO(n) 
    public void setFront(T element) { 
     PublicNode<T> node = new PublicNode<T>(element); 
     if (isEmpty()) { 
      throw new NoSuchElementException(); 
     }else{ 
      PublicNode<T> oldHead = this.head; 
      oldHead.setPrevious(node); 
      node.setNext(oldHead); 
      node.setPrevious(null); 
      this.head=node; 
     } 
     if(this.tail==null){ 
      this.tail=node; 
     } 
     this.size++; 

    } 

    public static void main(String[] args) { 
     // TODO Auto-generated method stub 
     CircularList<Integer> list = new CircularLinkedList<Integer>(); 
     for (int i = 1; i <= 4; i++) { 
      list.addLast(i); 
     } 

     System.out.println("\nShould print 1 2 3 4 1 2 3 4 1 2 3"); 
     Iterator<Integer> iter = list.iterator(); 
     for (int i = 1; iter.hasNext() && i <= 11; i++) { 
      System.out.print(" " + iter.next()); 
     } 
     System.out.println(); 

     list.setFront(3); 

     System.out.println("Should print 3 4 1 2 3 4 1 2 3 4 1"); 
     iter = list.iterator(); 
     for (int i = 1; iter.hasNext() && i <= 11; i++) { 
      System.out.print(" " + iter.next()); 
     } 
     System.out.println(); 

     list.addLast(-1); 

     System.out.println("Should print 3 4 1 2 -1 3 4 1 2 -1 3"); 
     iter = list.iterator(); 
     for (int i = 1; iter.hasNext() && i <= 11; i++) { 
      System.out.print(" " + iter.next()); 
     } 
     System.out.println(); 

     list.remove(4); 

     System.out.println("Should print 3 1 2 -1 3 1 2 -1 3 1 2"); 
     iter = list.iterator(); 
     for (int i = 1; iter.hasNext() && i <= 11; i++) { 
      System.out.print(" " + iter.next()); 
     } 
    } 

} 

Answer 1

嘗試這樣的事情在else從setFront()

PublicNode<T> node = head.next(); 
PublicNode<T> nodeToBeFound; 
while(node!=head){ 
    is(node.element() == element) 
     nodeToBeFound = node; 
    node = node.next(); 
} 
head = nodeToBeFound; 
tail = head.previous(); 

Answer 2

在CircularLinkedList<T>.setFront(T)您正在創建一個新節點並添加那到了前面循環列表而不是找到具有給定值的節點，並修改CircularLinkedList<T>.head以引用找到的節點。