# Program to Create and Display a Circular Linked List

Program to Create and Display a Circular Linked List on fibonacci, factorial, prime, armstrong, swap, reverse, search, sort, stack, queue, array, linkedlist, tree, graph etc.

## Q. Program to create and display a circular linked list.

### Explanation

In this program, we will create a circular linked list and print all the nodes present in the list.

The circular linked list is a kind of linked list. First thing first, the node is an element of the list, and it has two parts that are, data and next. Data represents the data stored in the node and next is the pointer that will point to next node. Head will point to the first element of the list, and tail will point to the last element in the list. In the simple linked list, all the nodes will point to their next element and tail will point to null.

The circular linked list is the collection of nodes in which tail node also point back to head node. The diagram shown below depicts a circular linked list. Node A represents head and node D represents tail. So, in this list, A is pointing to B, B is pointing to C and C is pointing to D but what makes it circular is that node D is pointing back to node A.

### Algorithm

1. Define a Node class which represents a node in the list. It has two properties data and next which will point to the next node.
2. Define another class for creating the circular linked list and it has two nodes: head and tail. It has two methods: add() and display() .
1. It first checks whether the head is null, then it will insert the node as the head.
2. Both head and tail will point to the newly added node.
3. If the head is not null, the new node will be the new tail, and the new tail will point to the head as it is a circular linked list.
4. display() will show all the nodes present in the list.
1. Define a new node 'current' that will point to the head.
2. Print current.data till current will points to head
3. Current will point to the next node in the list in each iteration.

## Solution

### Python

```#Represents the node of list.
class Node:
def __init__(self,data):
self.data = data;
self.next = None;

class CreateList:
#Declaring head and tail pointer as null.
def __init__(self):
self.tail = Node(None);

#This function will add the new node at the end of the list.
newNode = Node(data);
#Checks if the list is empty.
#If list is empty, both head and tail would point to new node.
self.tail = newNode;
else:
#tail will point to new node.
self.tail.next = newNode;
#New node will become new tail.
self.tail = newNode;

#Displays all the nodes in the list
def display(self):
print("List is empty");
return;
else:
print("Nodes of the circular linked list: ");
#Prints each node by incrementing pointer.
print(current.data),
current = current.next;
print(current.data),

cl = CreateList();
#Displays all the nodes present in the list
cl.display();
```

Output:

```Nodes of the circular linked list:
1 2 3 4
```

### C

```#include <stdio.h>
#include <string.h>
#include <stdlib.h>

//Represents the node of list.
struct node{
int data;
struct node *next;
};

//Declaring head and tail pointer as null.
struct node *tail = NULL;

//This function will add the new node at the end of the list.
//Create new node
struct node *newNode = (struct node*)malloc(sizeof(struct node));
newNode->data = data;
//Checks if the list is empty.
//If list is empty, both head and tail would point to new node.
tail = newNode;
}else {
//tail will point to new node.
tail->next = newNode;
//New node will become new tail.
tail = newNode;
}
}

//This function will display the nodes of circular linked list
void display(){
printf("List is empty");
}
else{
printf("Nodes of the circular linked list: \n");
do{
//Prints each node by incrementing pointer.
printf("%d ", current->data);
current = current->next;
printf("\n");
}
}

int main()
{
//Displays all the nodes present in the list
display();

return 0;
}
```

Output:

```Nodes of the circular linked list:
1 2 3 4
```

### JAVA

```public class CreateList {
//Represents the node of list.
public class Node{
int data;
Node next;
public Node(int data) {
this.data = data;
}
}

//Declaring head and tail pointer as null.
public Node tail = null;

//This function will add the new node at the end of the list.
//Create new node
Node newNode = new Node(data);
//Checks if the list is empty.
//If list is empty, both head and tail would point to new node.
tail = newNode;
}
else {
//tail will point to new node.
tail.next = newNode;
//New node will become new tail.
tail = newNode;
}
}

//Displays all the nodes in the list
public void display() {
System.out.println("List is empty");
}
else {
System.out.println("Nodes of the circular linked list: ");
do{
//Prints each node by incrementing pointer.
System.out.print(" "+ current.data);
current = current.next;
System.out.println();
}
}

public static void main(String[] args) {
CreateList cl = new CreateList();
//Displays all the nodes present in the list
cl.display();
}
}
```

Output:

```Nodes of the circular linked list:
1 2 3 4
```

### C#

``` using System;
{
public class Program
{
//Represents the node of list.
public class Node<T>{
public T data;
public Node<T> next;
public Node(T value) {
data = value;
next = null;
}
}

public class CreateList<T>{
protected Node<T> tail = null;

//This function will add the new node at the end of the list.
//Create new node
Node<T> newNode = new Node<T>(data);
//Checks if the list is empty.
tail = newNode;
}else{
//tail will point to new node.
tail.next = newNode;
//New node will become new tail.
tail = newNode;
}
}

//Displays all the nodes in the list
public void display(){
Node<T> current;
Console.WriteLine("List is empty");
}
else{
//Prints each node by incrementing pointer.
Console.WriteLine("Nodes of the circular linked list: ");
Console.Write(" "+current.data);
}
}
}
}

public static void Main()
{

CreateList<int> cl = new CreateList<int>();
//Displays all the nodes present in the list
cl.display();
}
}
}
```

Output:

```Nodes of the circular linked list:
1 2 3 4
```

### PHP

```<!DOCTYPE html>
<html>
<body>
<?php
//Represents the node of list.
class Node{
public \$data;
public \$next;
function __construct(\$data){
\$this->data = \$data;
\$this->next = NULL;
}
}
class CreateList{
//Declaring head and tail pointer as null.
private \$tail;
function __construct(){
\$this->tail = NULL;
}
//This function will add the new node at the end of the list.
//Create new node
\$newNode = new Node(\$data);
//Checks if the list is empty.
//If list is empty, both head and tail would point to new node.
\$this->tail = \$newNode;
}
else{
//tail will point to new node.
\$this->tail->next = \$newNode;
//New node will become new tail.
\$this->tail = \$newNode;
}
}
//Displays all the nodes in the list
function display() {
echo "List is empty";
}
else {
echo "Nodes of the circular linked list: <br>";
do{
//Prints each node by incrementing pointer.
echo(" \$current->data");
\$current = \$current->next;
echo "<br>";
}
}
}
\$cl = new CreateList();
//Displays all the nodes present in the list
\$cl->display();
?>
</body>
</html>
```

Output:

```Nodes of the circular linked list:
1 2 3 4
```

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