Circular Linked Lists in Data Structures

1. Insertion at the beginning: Let us understand this with an illustration. Suppose we want to insert a node with the value 6 at the beginning of the given circular linked list. The following three steps to accomplish this operation:
   1. Create a new node
      • allocate memory for new Node
      • assign the data to the new Node.

   
   2. store the address of the current first node in the new Node (i.e. pointing the new Node to the current first node)
   3. point the last node to new Node (i.e making new Node as head)

   

   Example of Insertion at the beginning of a Circular Linked List

   • Python
   • Java
   • C++

   
   class Node:
       def __init__(self, data):
           self.data = data
           self.next = None
   
   
   class CircularLinkedList:
       def __init__(self):
           self.last = None  # Pointer to the last Node of the Circular Linked List.
   
       def add_begin(self, data):
           if self.last is None:
               return self.add_to_empty(data)
   
           new_node = Node(data)
           new_node.next = self.last.next
           self.last.next = new_node
   
           return self.last
   
       def add_to_empty(self, data):
           if self.last is not None:
               return self.last  # The list is not empty
   
           new_node = Node(data)
           self.last = new_node
           self.last.next = self.last  # Linking back to itself in a circular manner
           return self.last
   
       def display_list(self, message="Circular Linked List"):
           if self.last is None:
               print("The list is empty")
               return
   
           print(message + ": ", end="")
           current_node = self.last.next
           while True:
               print(current_node.data, end=" ")
               current_node = current_node.next
               if current_node == self.last.next:
                   break
           print()
   
   
   circular_linked_list = CircularLinkedList()
   
   # Creating a circular linked list with data 1, 2, and 3
   circular_linked_list.add_to_empty(3)
   circular_linked_list.add_begin(2)
   circular_linked_list.add_begin(1)
   
   # Display the circular linked list before addition
   circular_linked_list.display_list("Before Insertion")
   
   # Adding a node with data 6 to the beginning
   circular_linked_list.add_begin(6)
   
   # Display the circular linked list after addition
   circular_linked_list.display_list("After Insertion")
       

   Run Code >>

   
   class Node {
       int data;
       Node next;
   
       public Node(int data) {
           this.data = data;
           this.next = null;
       }
   }
   
   class CircularLinkedList {
       Node last;
   
       public CircularLinkedList() {
           last = null;
       }
   
       public Node addBegin(int data) {
           if (last == null) {
               return addToEmpty(data);
           }
   
           Node newNode = new Node(data);
           newNode.next = last.next;
           last.next = newNode;
   
           return last;
       }
   
       public Node addToEmpty(int data) {
           if (last != null) {
               return last; // The list is not empty
           }
   
           Node newNode = new Node(data);
           last = newNode;
           last.next = last; // Linking back to itself in a circular manner
           return last;
       }
   
       public void displayList(String message) {
           if (last == null) {
               System.out.println("The list is empty");
               return;
           }
   
           System.out.print(message + ": ");
           Node current = last.next;
           do {
               System.out.print(current.data + " ");
               current = current.next;
           } while (current != last.next);
           System.out.println();
       }
   
       public static void main(String[] args) {
           CircularLinkedList circularLinkedList = new CircularLinkedList();
   
           // Creating a circular linked list with data 1, 2, and 3
           circularLinkedList.addToEmpty(1);
           circularLinkedList.addBegin(2);
           circularLinkedList.addBegin(3);
   
           // Display the circular linked list before addition
           circularLinkedList.displayList("Before Insertion");
   
           // Adding a node with data 6 to the beginning
           circularLinkedList.addBegin(6);
   
           // Display the circular linked list after addition
           circularLinkedList.displayList("After Insertion");
       }
   }
       

   Run Code >>

   
   #include <iostream>
   
   class Node {
   public:
       int data;
       Node* next;
   
       Node(int data) : data(data), next(nullptr) {}
   };
   
   class CircularLinkedList {
   private:
       Node* last;
   
   public:
       CircularLinkedList() : last(nullptr) {}
   
       Node* addBegin(int data) {
           if (last == nullptr) {
               return addToEmpty(data);
           }
   
           Node* newNode = new Node(data);
           newNode->next = last->next;
           last->next = newNode;
   
           return last;
       }
   
       Node* addToEmpty(int data) {
           if (last != nullptr) {
               return last; // The list is not empty
           }
   
           Node* newNode = new Node(data);
           last = newNode;
           last->next = last; // Linking back to itself in a circular manner
           return last;
       }
   
       void displayList(const std::string& message) {
           if (last == nullptr) {
               std::cout << "The list is empty" << std::endl;
               return;
           }
   
           std::cout << message << ": ";
           Node* current = last->next;
           do {
               std::cout << current->data << " ";
               current = current->next;
           } while (current != last->next);
           std::cout << std::endl;
       }
   };
   
   int main() {
       CircularLinkedList circularLinkedList;
   
       // Creating a circular linked list with data 1, 2, and 3
       circularLinkedList.addToEmpty(1);
       circularLinkedList.addBegin(2);
       circularLinkedList.addBegin(3);
   
       // Display the circular linked list before addition
       circularLinkedList.displayList("Before Insertion");
   
       // Adding a node with data 6 to the beginning
       circularLinkedList.addBegin(6);
   
       // Display the circular linked list after addition
       circularLinkedList.displayList("After Insertion");
   
       return 0;
   }
       

   Run Code >>

   Output

   Before Insertion: 1 2 3 
   After Insertion: 6 1 2 3   

2. Insertion at a specific position/in between the nodes: Suppose we want to insert a node with value 6 after the head node with value 1 in the given circular linked list. The following three steps to accomplish this operation:
   1. travel to the node given i.e. node 1
   2. point the next of new Node to the node next to node 1
   3. store the address of the new Node at the next of node 1.

   

   Example of Insertion in Between or at a Given Position in a Circular Linked List

   • Python
   • Java
   • C++

   
   class Node:
       def __init__(self, data):
           self.data = data
           self.next = None
   
   
   class CircularLinkedList:
       def __init__(self):
           self.last = None
   
       def add_after(self, data, item):
           if self.last is None:
               return None
   
           temp, P = None, self.last.next
           while True:
               if P.data == item:
                   temp = Node(data)
                   temp.next = P.next
                   P.next = temp
   
                   if P == self.last:
                       self.last = temp
                   return self.last
               P = P.next
               if P == self.last.next:
                   print(item, "not present in the list.")
                   break
   
       def display_list(self, message):
           if self.last is None:
               print("The list is empty")
               return
   
           print(message + ": ", end="")
           current = self.last.next
           while True:
               print(current.data, end=" ")
               current = current.next
               if current == self.last.next:
                   break
           print()
   
   circular_linked_list = CircularLinkedList()
   
   # Creating a circular linked list with data 1, 2, and 3
   circular_linked_list.last = Node(1)
   circular_linked_list.last.next = circular_linked_list.last  # Pointing to itself initially
   
   circular_linked_list.add_after(2, 1)
   circular_linked_list.add_after(3, 2)
   
   # Display the circular linked list before insertion
   circular_linked_list.display_list("Before Insertion")
   
   # Adding a node with data 6 after node with data 1
   circular_linked_list.add_after(6, 1)
   
   # Display the circular linked list after insertion
   circular_linked_list.display_list("After Insertion")
       

   Run Code >>

   
   class Node {
       int data;
       Node next;
   
       public Node(int val) {
           data = val;
           next = null;
       }
   }
   
   class CircularLinkedList {
       Node last;
   
       public Node addAfter(Node last, int data, int item) {
           if (last == null)
               return null;
   
           Node temp, P;
           P = last.next;
           do {
               if (P.data == item) {
                   temp = new Node(data);
                   temp.next = P.next;
                   P.next = temp;
   
                   if (P == last)
                       last = temp;
                   return last;
               }
               P = P.next;
           } while (P != last.next);
   
           System.out.println(item + " not present in the list.");
           return last;
       }
   
       public void displayList(String message) {
           if (last == null) {
               System.out.println("The list is empty");
               return;
           }
   
           System.out.print(message + ": ");
           Node current = last.next;
           do {
               System.out.print(current.data + " ");
               current = current.next;
           } while (current != last.next);
           System.out.println();
       }
   
       public static void main(String[] args) {
           CircularLinkedList circularLinkedList = new CircularLinkedList();
   
           // Creating a circular linked list with data 1, 2, and 3
           circularLinkedList.last = new Node(3);
           circularLinkedList.last.next = circularLinkedList.last;  // Pointing to itself initially
   
           circularLinkedList.addAfter(circularLinkedList.last, 2, 3);
           circularLinkedList.addAfter(circularLinkedList.last, 1, 3);
   
           // Display the circular linked list before insertion
           circularLinkedList.displayList("Before Insertion");
   
           // Adding a node with data 6 after node with data 1
           circularLinkedList.addAfter(circularLinkedList.last, 6, 1);
   
           // Display the circular linked list after insertion
           circularLinkedList.displayList("After Insertion");
       }
   }
       

   Run Code >>

   
   #include <iostream>
   
   // Node structure for the Circular Linked List
   struct Node {
       int data;
       Node* next;
   
       // Constructor
       Node(int val) : data(val), next(nullptr) {}
   };
   
   // Function to add a node after a specific node
   Node* addAfter(Node* last, int data, int item) {
       if (last == nullptr)
           return nullptr;
   
       Node* temp, *P;
       P = last->next;
       do {
           if (P->data == item) {
               temp = new Node(data);
               temp->next = P->next;
               P->next = temp;
   
               if (P == last)
                   last = temp;
               return last;
           }
           P = P->next;
       } while (P != last->next);
   
       std::cout << item << " not present in the list." << std::endl;
       return last;
   }
   
   // Function to display the Circular Linked List
   void displayList(Node* last, const std::string& message) {
       if (last == nullptr) {
           std::cout << "The list is empty" << std::endl;
           return;
       }
   
       std::cout << message << ": ";
       Node* current = last->next;
       do {
           std::cout << current->data << " ";
           current = current->next;
       } while (current != last->next);
       std::cout << std::endl;
   }
   
   int main() {
       Node* last = nullptr;
   
       // Creating a circular linked list with data 1, 2, and 3
       last = new Node(1);
       last->next = last;  // Pointing to itself initially
   
       last = addAfter(last, 2, 1);
       last = addAfter(last, 3, 2);
   
       // Display the circular linked list before insertion
       displayList(last, "Before Insertion");
   
       // Adding a node with data 6 after node with data 1
       last = addAfter(last, 6, 1);
   
       // Display the circular linked list after insertion
       displayList(last, "After Insertion");
   
       // Clean up memory (optional in this example)
       delete last;
   
       return 0;
   }
       

   Run Code >>

   Output

   Before Insertion: 1 2 3 
   After Insertion: 1 6 2 3     

3. Insertion at the end: Suppose we want to insert a node with value 6 after the last node with value 3 in the given circular linked list. The following three steps to accomplish this operation:
   1. store the address of the head node to the next of new Node (making new Node the last node)
   2. point the current last node to new Node
   3. make new Node as the last node

   

   Example of Insertion at the End of a Circular Linked List

   • Python
   • Java
   • C++

   
   class Node:
       def __init__(self, data):
           self.data = data
           self.next = None
   
   
   class CircularLinkedList:
       def __init__(self):
           self.last = None
   
       def add_end(self, data):
           if self.last is None:
               return None
   
           new_node = Node(data)
   
           new_node.next = self.last.next
           self.last.next = new_node
           self.last = new_node
   
           return self.last
   
       def display_list(self, message):
           if self.last is None:
               print("The list is empty")
               return
   
           print(message + ": ", end="")
           current = self.last.next
           while True:
               print(current.data, end=" ")
               current = current.next
               if current == self.last.next:
                   break
           print()
   
   circular_linked_list = CircularLinkedList()
   
   # Creating a circular linked list with data 1, 2, and 3
   circular_linked_list.last = Node(1)
   circular_linked_list.last.next = circular_linked_list.last  # Pointing to itself initially
   
   circular_linked_list.add_end(2)
   circular_linked_list.add_end(3)
   
   # Display the circular linked list before addition
   circular_linked_list.display_list("Before Insertion")
   
   # Adding a node with data 6 at the end
   circular_linked_list.add_end(6)
   
   # Display the circular linked list after addition
   circular_linked_list.display_list("After Insertion")
       

   Run Code >>

   
   class Node {
       int data;
       Node next;
   
       public Node(int val) {
           data = val;
           next = null;
       }
   }
   
   class CircularLinkedList {
       Node last;
   
       public Node addEnd(Node last, int data) {
           if (last == null)
               return null;
   
           Node newNode = new Node(data);
   
           newNode.next = last.next;
           last.next = newNode;
           last = newNode;
   
           return last;
       }
   
       public void displayList(String message) {
           if (last == null) {
               System.out.println("The list is empty");
               return;
           }
   
           System.out.print(message + ": ");
           Node current = last.next;
           do {
               System.out.print(current.data + " ");
               current = current.next;
           } while (current != last.next);
           System.out.println();
       }
   
       public static void main(String[] args) {
           CircularLinkedList circularLinkedList = new CircularLinkedList();
   
           // Creating a circular linked list with data 1, 2, and 3
           circularLinkedList.last = new Node(1);
           circularLinkedList.last.next = circularLinkedList.last;  // Pointing to itself initially
   
           circularLinkedList.addEnd(circularLinkedList.last, 2);
           circularLinkedList.addEnd(circularLinkedList.last, 3);
   
           // Display the circular linked list before addition
           circularLinkedList.displayList("Before Insertion");
   
           // Adding a node with data 6 at the end
           circularLinkedList.addEnd(circularLinkedList.last, 6);
   
           // Display the circular linked list after addition
           circularLinkedList.displayList("After Insertion");
       }
   }
       

   Run Code >>

   
   #include <iostream>
   
   // Node structure for the Circular Linked List
   struct Node {
       int data;
       Node* next;
   
       // Constructor
       Node(int val) : data(val), next(nullptr) {}
   };
   
   // Function to add a node at the end
   Node* addEnd(Node* last, int data) {
       if (last == nullptr)
           return nullptr;
   
       Node* newNode = new Node(data);
   
       newNode->next = last->next;
       last->next = newNode;
       last = newNode;
   
       return last;
   }
   
   // Function to display the Circular Linked List
   void displayList(Node* last, const std::string& message) {
       if (last == nullptr) {
           std::cout << "The list is empty" << std::endl;
           return;
       }
   
       std::cout << message << ": ";
       Node* current = last->next;
       do {
           std::cout << current->data << " ";
           current = current->next;
       } while (current != last->next);
       std::cout << std::endl;
   }
   
   int main() {
       Node* last = nullptr;
   
       // Creating a circular linked list with data 1, 2, and 3
       last = new Node(1);
       last->next = last;  // Pointing to itself initially
   
       last = addEnd(last, 2);
       last = addEnd(last, 3);
   
       // Display the circular linked list before addition
       displayList(last, "Before Insertion");
   
       // Adding a node with data 6 at the end
       last = addEnd(last, 6);
   
       // Display the circular linked list after addition
       displayList(last, "After Insertion");
   
       // Clean up memory (optional in this example)
       delete last;
   
       return 0;
   }
       

   Run Code >>

   Output

   Before Insertion: 1 2 3 
   After Insertion: 1 2 3 6    

2. Deletion

1. If it's the only node: Follow the given two steps procedure
   1. free the memory occupied by the node
   2. store NULL in the last
2. If it's the last node: Follow the given four steps procedure
   1. find the node before the last node (let it be temp)
   2. store the address of the node next to the last node in temp
   3. free the memory of the last
   4. make temp the last node

   

3. If it's any other node: Follow the given four steps procedure
   1. travel to the node to be deleted (here we are deleting node two)
   2. Let the node before node two be temp
   3. store the address of the node next to two in temp
   4. free the memory of two

   

Example of Deletion Operation in a Circular Linked List

• Python
• Java
• C++
class Node:
    def __init__(self, data):
        self.data = data
        self.next = None


class CircularLinkedList:
    def __init__(self):
        self.last = None

    def push(self, data):
        ptr1 = Node(data)
        ptr1.next = self.last

        if self.last is not None:
            temp = self.last
            while temp.next != self.last:
                temp = temp.next
            temp.next = ptr1
        else:
            ptr1.next = ptr1

        self.last = ptr1

    def print_list(self):
        temp = self.last
        if self.last is not None:
            while True:
                print(temp.data, end=" ")
                temp = temp.next
                if temp == self.last:
                    break
        print()

    def delete_node(self, key):
        if self.last is None:
            return

        if self.last.data == key and self.last.next == self.last:
            self.last = None
            return

        temp = self.last
        d = None

        if self.last.data == key:
            while temp.next != self.last:
                temp = temp.next

            temp.next = self.last.next
            self.last = temp.next
            return

        while temp.next != self.last and temp.next.data != key:
            temp = temp.next

        if temp.next.data == key:
            d = temp.next
            temp.next = d.next
        else:
            print("No such key found")


# Creating a circular linked list with data 1, 2, and 3
circular_linked_list = CircularLinkedList()
circular_linked_list.push(3)
circular_linked_list.push(2)
circular_linked_list.push(1)

# Display the circular linked list before deletion
print("List Before Deletion:", end=" ")
circular_linked_list.print_list()

# Deleting the first node
circular_linked_list.delete_node(1)

# Display the circular linked list after deletion
print("List after deletion of first node:", end=" ")
circular_linked_list.print_list()

circular_linked_list.push(1)

# Deleting a node in between (node with data 2)
circular_linked_list.delete_node(2)

# Display the circular linked list after deletion
print("List after deletion of an inner node:", end=" ")
circular_linked_list.print_list()

# Deleting the last node
circular_linked_list.delete_node(3)

# Display the circular linked list after deletion
print("List after deletion of last node:", end=" ")
circular_linked_list.print_list()
    
Run Code >>
class Node {
    int data;
    Node next;

    // Constructor
    Node(int val) {
        data = val;
        next = null;
    }
}

class CircularLinkedList {
    Node last;

    // Function to insert a node at the beginning of
    // a Circular linked list
    void push(int data) {
        Node ptr1 = new Node(data);
        ptr1.next = last;

        if (last != null) {
            Node temp = last;
            while (temp.next != last)
                temp = temp.next;
            temp.next = ptr1;
        } else {
            ptr1.next = ptr1;
        }

        last = ptr1;
    }

    // Function to print nodes in a given
    // circular linked list
    void printList() {
        Node temp = last;
        if (last != null) {
            do {
                System.out.print(temp.data + " ");
                temp = temp.next;
            } while (temp != last);
        }

        System.out.println();
    }

    // Function to delete a given node from the list
    void deleteNode(int key) {
        if (last == null)
            return;

        if (last.data == key && last.next == last) {
            last = null;
            return;
        }

        Node temp = last;
        Node d;

        if (last.data == key) {
            while (temp.next != last)
                temp = temp.next;

            temp.next = last.next;
            last = temp.next;
            return;
        }

        while (temp.next != last && temp.next.data != key) {
            temp = temp.next;
        }

        if (temp.next.data == key) {
            d = temp.next;
            temp.next = d.next;
        } else {
            System.out.println("No such key found");
        }
    }

    public static void main(String[] args) {
        CircularLinkedList circularLinkedList = new CircularLinkedList();

        // Creating a circular linked list with data 1, 2, and 3
        circularLinkedList.push(3);
        circularLinkedList.push(2);
        circularLinkedList.push(1);

        // Display the circular linked list before deletion
        System.out.print("List Before Deletion: ");
        circularLinkedList.printList();

        // Deleting the first node
        circularLinkedList.deleteNode(1);

        // Display the circular linked list after deletion
        System.out.print("List after deletion of first node: ");
        circularLinkedList.printList();

        circularLinkedList.push(1);

        // Deleting a node in between (node with data 2)
        circularLinkedList.deleteNode(2);

        // Display the circular linked list after deletion
        System.out.print("List after deletion of an inner node: ");
        circularLinkedList.printList();

        // Deleting the last node
        circularLinkedList.deleteNode(3);

        // Display the circular linked list after deletion
        System.out.print("List after deletion of last node: ");
        circularLinkedList.printList();
    }
}
    
Run Code >>
#include <iostream>

class Node {
public:
    int data;
    Node* next;

    // Constructor
    Node(int val) : data(val), next(nullptr) {}
};

void push(Node** head_ref, int data) {
    Node* ptr1 = new Node(data);
    ptr1->next = *head_ref;

    if (*head_ref != nullptr) {
        Node* temp = *head_ref;
        while (temp->next != *head_ref)
            temp = temp->next;
        temp->next = ptr1;
    } else {
        ptr1->next = ptr1;
    }

    *head_ref = ptr1;
}

void printList(Node* head) {
    Node* temp = head;
    if (head != nullptr) {
        do {
            std::cout << temp->data << " ";
            temp = temp->next;
        } while (temp != head);
    }

    std::cout << std::endl;
}

void deleteNode(Node** head, int key) {
    if (*head == nullptr)
        return;

    if ((*head)->data == key && (*head)->next == *head) {
        delete *head;
        *head = nullptr;
        return;
    }

    Node* last = *head;
    Node* d;

    if ((*head)->data == key) {
        while (last->next != *head)
            last = last->next;

        last->next = (*head)->next;
        delete *head;
        *head = last->next;
        return;
    }

    while (last->next != *head && last->next->data != key) {
        last = last->next;
    }

    if (last->next->data == key) {
        d = last->next;
        last->next = d->next;
        delete d;
    } else {
        std::cout << "No such key found" << std::endl;
    }
}

int main() {
    Node* head = nullptr;

    // Creating a circular linked list with data 1, 2, and 3
    push(&head, 3);
    push(&head, 2);
    push(&head, 1);

    // Display the circular linked list before deletion
    std::cout << "List Before Deletion: ";
    printList(head);

    // Deleting the first node
    deleteNode(&head, 1);

    // Display the circular linked list after deletion
    std::cout << "List after deletion of first node: ";
    printList(head);
    
         push(&head, 1);
    // Deleting a node in between (node with data 2)
    deleteNode(&head, 2);

    // Display the circular linked list after deletion
    std::cout << "List after deletion of an inner node: ";
    printList(head);
    
    //  Deleting the last node
    deleteNode(&head, 3);

    // Display the circular linked list after deletion
    std::cout << "List after deletion of last node: ";
    printList(head);

    return 0;
}
    
Run Code >>

Output

List Before Deletion: 1 2 3 
List after deletion of first node: 2 3 
List after deletion of an inner node: 1 3 
List after deletion of last node: 1

3. Traversal

Example of Traversing a Circular Linked List

class Node:
    def __init__(self, data):
        self.data = data
        self.next = None

# Function to traverse and print the Circular Linked List
def display_list(last):
    if last is None:
        print("The list is empty")
        return

    current = last.next
    while True:
        print(current.data, end=" ")
        current = current.next
        if current == last.next:
            break
    print()

# Initialize nodes
last = None
one = Node(1)
two = Node(2)
three = Node(3)

# Connect nodes
one.next = two
two.next = three
three.next = one

# Save the address of the third node in last
last = three

# Displaying the circular linked list
display_list(last)
    

class Node {
    int data;
    Node next;

    // Constructor
    public Node(int data) {
        this.data = data;
        this.next = null;
    }
}

class CircularLinkedList {
    // Function to traverse and print the Circular Linked List
    static void displayList(Node last) {
        if (last == null) {
            System.out.println("The list is empty");
            return;
        }

        Node current = last.next;
        do {
            System.out.print(current.data + " ");
            current = current.next;
        } while (current != last.next);

        System.out.println();
    }

    public static void main(String[] args) {
        // Initialize nodes
        Node last = null;
        Node one = new Node(1);
        Node two = new Node(2);
        Node three = new Node(3);

        // Connect nodes
        one.next = two;
        two.next = three;
        three.next = one;

        // Save the address of the third node in last
        last = three;

        // Displaying the circular linked list
        displayList(last);
    }
}
    

#include <iostream>

// Define the node structure
struct Node {
    int data;
    Node* next;
};

// Function to traverse and print the Circular Linked List
void displayList(Node* last) {
    if (last == nullptr) {
        std::cout << "The list is empty" << std::endl;
        return;
    }

    Node* current = last->next;
    do {
        std::cout << current->data << " ";
        current = current->next;
    } while (current != last->next);

    std::cout << std::endl;
}

int main() {
    // Initialize nodes
    Node* last = nullptr;
    Node* one = nullptr;
    Node* two = nullptr;
    Node* three = nullptr;

    // Allocate memory
    one = new Node;
    two = new Node;
    three = new Node;

    // Assign data values
    one->data = 1;
    two->data = 2;
    three->data = 3;

    // Connect nodes
    one->next = two;
    two->next = three;
    three->next = one;

    // Save the address of the third node in last
    last = three;

    // Displaying the circular linked list
    displayList(last);

    // Clean up memory
    delete one;
    delete two;
    delete three;

    return 0;
}
    

Output

1 2 3     

Complexity Analysis of Circular Linked List Operations

Applications of Circular Linked List

1. This is used in multiplayer games to give each participant a chance to play.
2. In an operating system, a circular linked list can be used to organize many running applications.
3. In resource allocation difficulties, circular linked lists might be useful.
4. Circular linked lists are frequently used to build circular buffers.
5. They can also be used in simulation and gaming.

Advantages of Circular Linked Lists

1. Any node can be a starting point. We can traverse the whole list by starting from any point. We just need to stop when the first visited node is visited again.
2. Useful for the implementation of a queue. Unlike this implementation, we don’t need to maintain two-pointers for the front and rear if we use a circular linked list. We can maintain a pointer to the last inserted node and the front can always be obtained as next of last.
3. Circular lists are useful in applications to repeatedly go around the list. For example, when multiple applications are running on a PC, it is common for the operating system to put the running applications on a list and then cycle through them, giving each of them a slice of time to execute, and then making them wait while the CPU is given to another application. It is convenient for the operating system to use a circular list so that when it reaches the end of the list it can cycle around to the front of the list.
4. Circular Doubly Linked Lists are used for the implementation of advanced data structures like the Fibonacci Heap.
5. Implementing a circular linked list can be relatively easy compared to other more complex data structures like trees or graphs.

Disadvantages of Circular Linked Lists

1. Compared to singly linked lists, circular lists are more complex.
2. Reversing a circular list is more complicated than reversing a singly or doubly linked list.
3. The code can go into an infinite loop if it is not handled carefully.
4. It is harder to find the end of the list and control the loop.
5. Although circular linked lists can be efficient in certain applications, their performance can be slower than other data structures in certain cases, such as when the list needs to be sorted or searched.
6. Circular linked lists don’t provide direct access to individual nodes.

Summary

So, here we saw every aspect of a circular linked list in data structures. You might have got at least some idea regarding circular linked lists and their applications. I know it's quite difficult and tricky to understand the whole topic in a single go. There are a lot of concepts and logic to be understood in this. Therefore, refer to it again and again till you get thorough with the linked list in data structures. To test your knowledge of linked lists, enroll in our Dsa Course Free.