remove nth element.java

Uppgift 5 - Remove Nth element


class Uppgift5
{

    // Structure of node
    static class Node
    {
        int data;
        Node next;
    };

    // Function to insert node in a linked list
    static Node create(Node head, int x) {
        Node temp, ptr = head;
        temp = new Node();
        temp.data = x;
        temp.next = null;
        if (head == null){
            head = temp;
            display(head);
        }
        else{
            while (ptr.next != null)
            {
                ptr = ptr.next;
            }
            ptr.next = temp;
            display(head);
        }

        return head;
    }

    // Function to remove nth node from last
    static Node removeNthFromEnd(Node head, int B)
    {
        // To store length of the linked list
        int len = 0;
        Node tmp = head;
        while (tmp != null)
        {
            len++;
            tmp = tmp.next;
        }

        // B > length, then we can't remove node
        if (B > len)
        {
            System.out.print("Length of the linked list is " + len);
            System.out.print(" we can't remove "+ B +
                    "th node from the");
            System.out.print(" linked list\n");
            return head;
        }

        // We need to remove head node
        else if (B == len)
        {

            // Return head.next
            System.out.println("removing first element");
            return head.next;

        }
        else
        {
            // Remove len - B th node from starting
            int diff = len - B;
            Node prev= null;
            Node curr = head;
            for(int i = 0; i < diff; i++)
            {
                prev = curr;
                curr = curr.next;
            }
            prev.next = curr.next;
            return head;
        }

    }

    // This function prints contents of linked
// list starting from the given node
    static void display(Node head)
    {
        Node temp = head;
        while (temp != null)
        {
            System.out.print(temp.data + " ");
            temp = temp.next;
        }
        System.out.println();
    }

    // Driver code
    public static void main(String[] args)
    {
        Node head = null;

        head = create(head, 1);
        head = create(head, 2);
        head = create(head, 3);
        head = create(head, 4);


        System.out.print("Linked list before modification: \n");
        display(head);

        head = removeNthFromEnd(head, 3);
        System.out.print("Linked list after modification: \n");
        display(head);
    }
}