How to delete a node in a chained list in Java?

Question

I have the following java code but it’s not working properly. I need to delete a node from a chained list. Someone help me?

     /*
      Delete Node at a given position in a linked list 
       head pointer input could be NULL as well for empty list
         Node is defined as 
        class Node {
         int data;
         Node next;
     }
     */

   // This is a "method-only" submission. 

   // You only need to complete this method. 

    Node Delete(Node head, int position) {
    // Complete this method
    int cont=1;
    Node tmp=head;
    if(head==null)
    {
    return null;
    }
   if(position==0)
    {
    Node prox= head.next;
    head=prox;
    return head;
  }
  Node tmp=head;
  Node tmp2=head.next;
  while(cont<position)
  {
   tmp=tmp2;
    tmp2=tmp2.next;
    cont++;

 }
 tmp.next=tmp2.next;


 return head;
 }

Answer 1

I think this should work:

public static Node delete(Node head, int position) {
    if (head == null) return null;
    if (position == 0) {
        Node prox = head.next;
        head.next = null;
        return prox;
    }

    int cont = 1;
    Node tmp = head;
    Node tmp2 = head.next;

    while (cont < position) {
        tmp = tmp2;
        tmp2 = tmp2.next;
        cont++;
    }
    tmp.next = tmp2.next;
    tmp2.next = null;
    return head;
 }

There was a compilation error because you declared tmp twice. There were two lines Node tmp=head;.

Another difference is that I make the severed node stop pointing to some point in the middle of the list while doing noRetirado.next = null;. This helps the garbage collector and causes that if there is a reference to the node removed, it cannot be used to mess with the rest of the list from where it was taken.

I also changed the location where some variables are declared to declare them only when they are unavoidably required.