Question

Java Language

Add a method (convertToRing ()) that converts the list to a circular. This is,
which makes the last node instead of pointing to null point to the first.

Code:

class Node {

int value;

Node nextNode;

Node(int v, Node n)

{

value = v;

nextNode = n;

}

Node (int v)

{

this(v,null);

}

}

class LinkedList

{

Node head; //head = null;

LinkedList()

{

}

int length()

{

Node tempPtr;

int result = 0;

tempPtr = head;

while (tempPtr != null)

{

tempPtr = tempPtr.nextNode;

result = result + 1;

}

return(result);

}

void insertAt(int v, int position)

{

Node newNode = new Node(v,null);

Node tempPtr;

int tempPosition = 0;

if((head == null) || (position ==0))

{

newNode.nextNode = head;

head = newNode;

}

else {

tempPtr = head;

while((tempPtr.nextNode != null)&&(tempPosition < position -1))

{

tempPtr = tempPtr.nextNode;

tempPosition = tempPosition + 1;

}

if (tempPosition == (position - 1))

{

newNode.nextNode = tempPtr.nextNode;

tempPtr.nextNode = newNode;

}

}

}

public String toString()

{

Node tempPtr;

tempPtr = head;

String result = "";

while(tempPtr != null)

{

result = result + "[" + tempPtr.value + "| ]-->";

tempPtr = tempPtr.nextNode;

}

result = result + "null";

return result;

}

}

public class LinkedListDemoInsDel

{

public static void main(String[] args)

{

LinkedList aLinkedList = new LinkedList();

aLinkedList.insertAt(1,0);

aLinkedList.insertAt(9,1);

aLinkedList.insertAt(13,2);

aLinkedList.insertAt(8,1);

aLinkedList.insertAt(3,2);

System.out.println(aLinkedList);

System.out.println("Largo de lista: " + aLinkedList.length());

}

}

Answer 1

static Node convertToRing(Node head) 
{ 
    // declare a node variable  
    // start and assign head  
    // node into start node. 
    Node start = head; 
  
    // check that while head.next 
    // not equal to null then head  
    // points to next node. 
    while (head.next != null) 
        head = head.next; 
          
    // if head.next points to null  
    // then start assign to the  
    // head.next node. 
    head.next = start; 
    return start; 
}