How would you reverse a linked list in Java?

Question

Anonymous · Accepted Answer

List.reverse()

FGZ · Answer

First answer is incorrect (no such  method).  2nd answer is correct.  I've seen this question before where the expected answer is to manipulate the list.

reversi · Answer

public class LinkedListElement {

  private E _element;
  private LinkedListElement _next;

  public LinkedListElement(E element)
  {
    _element = element;
    _next = null;
  }

  public LinkedListElement(E element, LinkedListElement next)
  {
    _element = element;
    _next = next;
  }

  public E get()
  {
    return _element;
  }

  public LinkedListElement next()
  {
    return _next;
  }

  public void setNext(LinkedListElement next)
  {
    _next = next;
  }

  public static  LinkedListElement reverse(LinkedListElement e)
  {
    if (e == null) {
      return null;
    }
    LinkedListElement current = e;
    LinkedListElement next = e.next();
    e.setNext(null);
    while (next != null) {
      LinkedListElement forward = next.next();
      next.setNext(e);
      e = next;
      next = forward;
    }
    return e;
  }


}

David Shuai Lee · Answer

public void reverse(ReverseSinglyLinkedList singlyLinkedList){
        if(singlyLinkedList.isEmpty()){
            return;
        }
        Node currentNode = head;
        Node nextNode = head.nextNode;
        Node markNode;
        head.nextNode = null;
        while(nextNode!=null){
            markNode = nextNode.nextNode;
            nextNode.nextNode = currentNode;
            currentNode = nextNode;
            nextNode = markNode;
        }
        head = currentNode;
    }

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