Question

Build a doubly linked list with these operations:
AddToHead(10); AddToHead(20); AddToTail(30); AddToTail(40);
Build a sorted doubly linked list with these operations:
Add(30), Add(20), Add(40), Add(15), Add(35);

Answer 1

Build a doubly linked list with these operations:
AddToHead(10); AddToHead(20); AddToTail(30); AddToTail(40);

Code For Above Problem:(IN JAVA)

public class DoublyLinkedList {

        // Node of a doubly linked list
        private class Node {
                int data;
                Node next, prev;

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

        Node head;// refernce to the head node
        Node tail;// reference to the tail node

        public void AddToHead(int data) {
                /*
                 * allocate node put in the data
                 */
                Node newNode = new Node(data);

                // If list is empty
                if (head == null) {
                        // Both head and tail will point to newNode
                        head = tail = newNode;

                } else {
                        // newNode will be added before head such that head prev will point to newNode
                        head.prev = newNode;
                        // newNode's next will point to head
                        newNode.next = head;
                        // newNode will become new head
                        head = newNode;
                }

        }

        public void AddToTail(int data) {
                /*
                 * allocate node put in the data
                 */
                Node newNode = new Node(data);
                // If list is empty
                if (tail == null) {
                        // Both head and tail will point to newNode
                        head = tail = newNode;
                } else {
                        // newNode will be added after tail such that tail's next will point to newNode
                        tail.next = newNode;
                        // newNode's previous will point to tail
                        newNode.prev = tail;
                        // newNode will become new tail
                        tail = newNode;
                }
        }

        //Method to print the contents Of List
        public void print() {
                Node current = head;
                while (current != null) {
                        System.out.print(current.data + " ");
                        current = current.next;
                }
        }

        public static void main(String[] args) {

                //create new Object of DoublyLinkedList 
                DoublyLinkedList list = new DoublyLinkedList();
                //perform given operations
                list.AddToHead(10);
                list.AddToHead(20);
                list.AddToTail(30);
                list.AddToTail(40);

                //print the list
                list.print();
        }
}

Output Of Above Code:

20 10 30 40 

Images Of Code:

Image Of Output:

Build a sorted doubly linked list with these operations:
Add(30), Add(20), Add(40), Add(15), Add(35);

Code For Above Problem:(IN JAVA)

public class SortedDoublyLinkedList {

        // Node of a doubly linked list
        private class Node {
                int data;
                Node next, prev;

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

        Node head;// refernce to the head node
        Node tail;// reference to the tail node

        public void Add(int data) {
                
                /*
                 * allocate node put in the data
                 */
                Node newNode = new Node(data);
                Node current;

                // if list is empty
                if (head == null)
                        head = newNode;

                // if the node is to be inserted at the beginning
                // of the doubly linked list
                else if (head.data >= newNode.data) {
                        newNode.next = head;
                        newNode.next.prev = newNode;
                        head = newNode;
                }

                else {
                        current = head;

                        // locate the node after which the new node
                        // is to be inserted
                        while (current.next != null && current.next.data < newNode.data)
                                current = current.next;

                        /* Make the appropriate links */
                        newNode.next = current.next;

                        // if the new node is not inserted
                        // at the end of the list
                        if (current.next != null)
                                newNode.next.prev = newNode;

                        current.next = newNode;
                        newNode.prev = current;

                }
        }

        // Method to print the contents Of List
        public void print() {
                Node current = head;
                while (current != null) {
                        System.out.print(current.data + " ");
                        current = current.next;
                }
        }

        public static void main(String[] args) {

                //create new Object of SortedDoublyLinkedList
                SortedDoublyLinkedList list = new SortedDoublyLinkedList();
                // perform given operations
                list.Add(10);
                list.Add(20);
                list.Add(30);
                list.Add(40);
                list.print();

        }
}

Output Of Code:

10 20 30 40 

Images Of Code:

Image Of Output: