linkedlist

linked list

import java.io.*;

class LinkedList {

    Node last = null;

    // function to create the link list
    public void createList(int n) {
        Node node = new Node();
        node.value = n;
        node.next = last;
        last = node;
    }

    // function to print the list
    public void printList() {
        Node temp = this.last;
        while (temp != null) {
            System.out.println(temp.value);
            temp = temp.next;
        }
    }

    // function to count the number of nodes in the list
    public int countNode() {
        int count = 0;
        Node temp = last;
        while (temp != null) {
            count++;
            temp = temp.next;
        }
        return count;
    }

    // function to re arrange the nodes in the list
    public void rearrangeList(LinkedList linkedlist) {

        Node temp = linkedlist.last;
        switch (linkedlist.countNode() % 3) {
            case 1:
                Node node = temp;
                this.createList(node.value);
                temp = temp.next;
                break;
            case 2:
                Node node2 = temp;
                Node node1 = temp.next;
                this.createList(node1.value);
                this.createList(node2.value);
                temp = (temp.next).next;
                break;
        }// end of switch     

        while (temp != null) {

            Node node3 = temp;
            Node node2 = temp.next;
            Node node1 = (temp.next).next;

            this.createList(node2.value);
            this.createList(node3.value);
            this.createList(node1.value);

            temp = ((temp.next).next).next;

        }// end of the while loop

    }// end of function

    public static void main(String args[]) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        LinkedList linkedlist = new LinkedList();

        System.out.println("*****LinkedList rearranging****");
        System.out.println("*****Author ---> Bonnie ****");
        System.out.println("*****PLEASE ENTER NUMER >=3 ****");
        int n = 0;
        do {

            System.out.println("Input a number. *input 0 to stop");
            n = Integer.parseInt(br.readLine());
            if (n != 0) {
                linkedlist.createList(n);
            }

        } while (n != 0);

        System.out.println("=== the list after re-arranging ===");
        LinkedList _linkedlist = new LinkedList();
        _linkedlist.rearrangeList(linkedlist);
        _linkedlist.printList();

    }

}

class Node {

    int value;
    Node next;
}