从Java中的链表中删除节点

Question

I'm making a dictionary type program with LinkedList, but I cant use the LinkedList utility, I have to create my own, so I can't use any of those methods, I have to remove a node, and I can't for the life of me figure it out. I can do it on paper, but in the code, it either removes everything before it, or just freezes and such. Here's what I have so far on the delete method:

void delete(String w)
{ 
        WordMeaningNode temp = list;
        WordMeaningNode current = list;
        WordMeaningNode back = null;
        boolean found = false;
        while(current != null && !found)
        {
            if( current.WordMeaning.getTitle().equals(w))
            {
                found = true;
                System.out.println("found it!");
            }
            else
            {
                back = current;
                current = current.next;
            }
         temp = current.next; //this is where the problem starts
         back.next = temp;
         }
}

and here's how I'm calling it:

String delWord = JOptionPane.showInputDialog("Enter word to be deleted");
                WordMeaning.delete(delWord);

or maybe I'm just not understanding the coding concept, what my teacher wants is not actually "delete" the node, just redirect the node before the current, to the node after the current, can anyone help me please?

Answer 1

public boolean deleteMiddleNode(Node middleNode)
{
//error check:
if  (middleNode  ==  null  ||  middleNode.next  ==  null)
return false;

/*
middleNode is x in our example data above, but
is now changed to hold the data of node y:
*/
middleNode.data = middleNode.next.data;

/*tempNode now holds node z if following
the example above:  */
Node tempNode = middleNode.next.next;
//delete the old node Y from example above
delete(middleNode.next);
/*reset pointer so that the new "y" points
  to z
*/
middleNode.next = tempNode;
}

Answer 2

The "skipping" of the delete nodes needs to be in the matching if-statment.

Assumption 1: The variable 'list' always points to the first element of the list.

Assumption 2: The list is not circular. Otherwise the algorithm may not terminate.

But you also have to treat border cases (empty list, list with one element, if you delete the first entry) in addition to the implementation below.

 void delete(String w) { 
    WordMeaningNode current = list;
    WordMeaningNode back = null;
    boolean found = false;
    while(current != null && !found)
    {
        if( current.WordMeaning.getTitle().equals(w))
        {
            found = true;
            System.out.println("found it!");
            back.next = current.next;
        }
        else
        {
            back = current;
            current = current.next;
        }
     }
 }