How to set next value in a Circularly Linked List in Java?

Question

This is what I have so far:

public void insert(int position, ValueNode value) {
  if (position == 1) {
    this.nextInRow = value;
  }
  ValueNode current = this.getFirst();
  if (position > 1) {
    current.setNext(current.next);
  }
    value.setNextInRow(current.getNext());
}

The headnode is being set properly with the first if statement. In this list we already know the position, so I'm thinking we don't need a while loop since we know where to put the new node.

I create a temp node called current to hold the next node pointer, but right now it sets the pointer to null. My problem is I don't know where to point the next node pointer to. Any help would be very much appreciated.

Answer 1

Distinguish making a node with value and setting next node operations.

Your data structure can be like this:

class Node {
   int val;
   Node next;
   Node previous;

  //setters and getters and constructors

}

1) For all new values should have a node

Node createNode(int val) {
    Node newNode = new Node(val);
    newNode.next = null;
    newNode.previous = null;
    return newNode; 
}  

2) Locate newNode starting from root or hold a current node set it next

 currentNode.setNext(Node newNode);
 //iterate the currenNode with newNode
 currentNode = newNode;

 ...

 // implement the setNext and mark current as previous for newNode
 void setNextNode(Node newNode) {
      this.next = newNode;
      newNode.setPrevious(this); 
 }