Code:
import java.util.Scanner;
/* Class Node */
class Node
{
protected int data;
protected Node next, prev;
/* Constructor */
public Node()
{
next = null;
prev = null;
data = 0;
}
/* Constructor */
public Node(int d, Node n, Node p)
{
data = d;
next = n;
prev = p;
}
/* Function to set link to next node */
public void setLinkNext(Node n)
{
next = n;
}
/* Function to set link to previous node */
public void setLinkPrev(Node p)
{
prev = p;
}
/* Funtion to get link to next node */
public Node getLinkNext()
{
return next;
}
/* Function to get link to previous node */
public Node getLinkPrev()
{
return prev;
}
/* Function to set data to node */
public void setData(int d)
{
data = d;
}
/* Function to get data from node */
public int getData()
{
return data;
}
}
/* Class linkedList */
class linkedList
{
protected Node start;
protected Node end ;
public int size;
/* Constructor */
public linkedList()
{
start = null;
end = null;
size = 0;
}
/* Function to check if list is empty */
public boolean isEmpty()
{
return start == null;
}
/* Function to get size of list */
public int getSize()
{
return size;
}
/* Function to insert element at begining */
public void insertAtStart(int val)
{
Node nptr = new Node(val, null, null);
if (start == null)
{
nptr.setLinkNext(nptr);
nptr.setLinkPrev(nptr);
start = nptr;
end = start;
}
else
{
nptr.setLinkPrev(end);
end.setLinkNext(nptr);
start.setLinkPrev(nptr);
nptr.setLinkNext(start);
start = nptr;
}
size++ ;
}
/*Function to insert element at end */
public void insertAtEnd(int val)
{
Node nptr = new Node(val, null, null);
if (start == null)
{
nptr.setLinkNext(nptr);
nptr.setLinkPrev(nptr);
start = nptr;
end = start;
}
else
{
nptr.setLinkPrev(end);
end.setLinkNext(nptr);
start.setLinkPrev(nptr);
nptr.setLinkNext(start);
end = nptr;
}
size++;
}
/* Function to insert element at position */
public void insertAtPos(int val , int pos)
{
Node nptr = new Node(val, null, null);
if (pos == 1)
{
insertAtStart(val);
return;
}
Node ptr = start;
for (int i = 2; i <= size; i++)
{
if (i == pos)
{
Node tmp = ptr.getLinkNext();
ptr.setLinkNext(nptr);
nptr.setLinkPrev(ptr);
nptr.setLinkNext(tmp);
tmp.setLinkPrev(nptr);
}
ptr = ptr.getLinkNext();
}
size++ ;
}
/* Function to delete node at position */
public void deleteAtPos(int pos)
{
if (pos == 1)
{
if (size == 1)
{
start = null;
end = null;
size = 0;
return;
}
start = start.getLinkNext();
start.setLinkPrev(end);
end.setLinkNext(start);
size--;
return ;
}
if (pos == size)
{
end = end.getLinkPrev();
end.setLinkNext(start);
start.setLinkPrev(end);
size-- ;
}
Node ptr = start.getLinkNext();
for (int i = 2; i <= size; i++)
{
if (i == pos)
{
Node p = ptr.getLinkPrev();
Node n = ptr.getLinkNext();
p.setLinkNext(n);
n.setLinkPrev(p);
size-- ;
return;
}
ptr = ptr.getLinkNext();
}
}
/* Function to display status of list */
public void display()
{
System.out.print("\nCircular Doubly Linked List = ");
Node ptr = start;
if (size == 0)
{
System.out.print("empty\n");
return;
}
if (start.getLinkNext() == start)
{
System.out.print(start.getData()+ " <-> "+ptr.getData()+ "\n");
return;
}
System.out.print(start.getData()+ " <-> ");
ptr = start.getLinkNext();
while (ptr.getLinkNext() != start)
{
System.out.print(ptr.getData()+ " <-> ");
ptr = ptr.getLinkNext();
}
System.out.print(ptr.getData()+ " <-> ");
ptr = ptr.getLinkNext();
System.out.print(ptr.getData()+ "\n");
}
}
/* Class CircularDoublyLinkedList */
public class CircularDoublyLinkedList
{
public static void main(String[] args)
{
Scanner scan = new Scanner(System.in);
/* Creating object of linkedList */
linkedList list = new linkedList();
System.out.println("Circular Doubly Linked List Test\n");
char ch;
/* Perform list operations */
do
{
System.out.println("\nCircular Doubly Linked List Operations\n");
System.out.println("1. insert at begining");
System.out.println("2. insert at end");
System.out.println("3. insert at position");
System.out.println("4. delete at position");
System.out.println("5. check empty");
System.out.println("6. get size");
int choice = scan.nextInt();
switch (choice)
{
case 1 :
System.out.println("Enter integer element to insert");
list.insertAtStart( scan.nextInt() );
break;
case 2 :
System.out.println("Enter integer element to insert");
list.insertAtEnd( scan.nextInt() );
break;
case 3 :
System.out.println("Enter integer element to insert");
int num = scan.nextInt() ;
System.out.println("Enter position");
int pos = scan.nextInt() ;
if (pos < 1 || pos > list.getSize() )
System.out.println("Invalid position\n");
else
list.insertAtPos(num, pos);
break;
case 4 :
System.out.println("Enter position");
int p = scan.nextInt() ;
if (p < 1 || p > list.getSize() )
System.out.println("Invalid position\n");
else
list.deleteAtPos(p);
break;
case 5 :
System.out.println("Empty status = "+ list.isEmpty());
break;
case 6 :
System.out.println("Size = "+ list.getSize() +" \n");
break;
default :
System.out.println("Wrong Entry \n ");
break;
}
/* Display List */
list.display();
System.out.println("\nDo you want to continue (Type y or n) \n");
ch = scan.next().charAt(0);
} while (ch == 'Y'|| ch == 'y');
}
}
Output:
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
1
Enter integer element to insert
5
Circular Doubly Linked List = 5 <-> 5
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
1
Enter integer element to insert
7
Circular Doubly Linked List = 7 <-> 5 <-> 7
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
2
Enter integer element to insert
3
Circular Doubly Linked List = 7 <-> 5 <-> 3 <-> 7
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
3
Enter integer element to insert
2
Enter position
2
Circular Doubly Linked List = 7 <-> 2 <-> 5 <-> 3 <-> 7
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
3
Enter integer element to insert
4
Enter position
4
Circular Doubly Linked List = 7 <-> 2 <-> 5 <-> 4 <-> 3 <-> 7
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
6
Size = 5
Circular Doubly Linked List = 7 <-> 2 <-> 5 <-> 4 <-> 3 <-> 7
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
4
Enter position
1
Circular Doubly Linked List = 2 <-> 5 <-> 4 <-> 3 <-> 2
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
1
Enter integer element to insert
1
Circular Doubly Linked List = 1 <-> 2 <-> 5 <-> 4 <-> 3 <-> 1
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
4
Enter position
1
Circular Doubly Linked List = 2 <-> 5 <-> 4 <-> 3 <-> 2
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
4
Enter position
1
Circular Doubly Linked List = 5 <-> 4 <-> 3 <-> 5
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
4
Enter position
2
Circular Doubly Linked List = 5 <-> 3 <-> 5
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
4
Enter position
1
Circular Doubly Linked List = 3 <-> 3
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
4
Enter position
1
Circular Doubly Linked List = empty
Do you want to continue (Type y or n)
y
Circular Doubly Linked List Operations
1. insert at begining
2. insert at end
3. insert at position
4. delete at position
5. check empty
6. get size
5
Empty status = true
Circular Doubly Linked List = empty
Do you want to continue (Type y or n)
n
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