Question

Java Language:

Using program created in this lesson as a starting point, create a circular list with at least four nodes. A circular list is one where the last node is made to point to the first. Show that your list has a circular structure by printing its content using an iterative structure such as a while. This should cause your program to go into an infinite loop so you should include a conditional that limits the number of nodes to be printed to a specific value, for example 20.

Code:

class Node {

int value;

Node nextNode;

Node(int v, Node n)

{

value = v;

nextNode = n;

}

Node (int v)

{

this(v,null);

}

}

class Stack {

protected Node top;

Stack()

{

top = null;

}

boolean isEmpty()

{

return( top == null);

}

void push(int v)

{

Node tempPointer;

tempPointer = new Node(v);

tempPointer.nextNode = top;

top = tempPointer;

}

int pop()

{

int tempValue;

tempValue = top.value;

top = top.nextNode;

return tempValue;

}

void printStack()

{

Node aPointer = top;

String tempString = "";

while (aPointer != null)

{

tempString = tempString + aPointer.value + "\n";

aPointer = aPointer.nextNode;

System.out.println(tempString);

}

}

public class StackWithLinkedList{

public static void main(String[] args){

int popValue;

Stack myStack = new Stack();

myStack.push(5);

myStack.push(7);

myStack.push(9);

myStack.printStack();

popValue = myStack.pop();

popValue = myStack.pop();

myStack.printStack();

}

}

Answer 1

Node.java :

class Node {
      int value;
      Node nextNode;
      Node (int v){
          this.value=v;
      } 
}
-----------------------------

CLLOperations.java :

class CLLOperations{
          Node head=null,tail=null;
          //adding new node to CLL
      public void addNewNode(int value){
          Node newNode = new Node(value);
          if(this.head==null){
                  this.head=newNode;
                  this.tail=newNode;
                  newNode.nextNode=head;
          }else{
                  this.tail.nextNode=newNode;
                  this.tail= newNode;
                  this.tail.nextNode=head;                
          }
          System.out.println("Node "+value+"is added succesfully");
      }     
      //Displaying all nodes until count is 20 as per given question
      public void display(){
          Node current = this.head;
          if(this.head==null){
                  System.out.println("list is empty");
          }else{
                  for(int i=0;i<20;i++){
                          System.out.println(current.value);
                          current=current.nextNode;
          }
        }         
     }
}   
-----------------------------
CircularLinkedList.java

public class CircularLinkedList{
        public static void main(String[] args){
                CLLOperations cll = new CLLOperations();
                cll.addNewNode(10);
                cll.addNewNode(15);
                cll.addNewNode(11);
                cll.addNewNode(21);
                cll.display();
    }
}

The output of the program is as below: