Java Program to Count rotations in sorted and rotated linked list

// Program for count number of rotations in
// sorted linked list.
import java.util.*;

class GFG
{
  
/* Linked list node */
static class Node {
    int data;
    Node next;
};

// Function that count number of
// rotation in singly linked list.
static int countRotation(Node head)
{
  
    // declare count variable and assign it 1.
    int count = 0;

    // declare a min variable and assign to
    // data of head node.
    int min = head.data;

    // check that while head not equal to null.
    while (head != null) {

        // if min value is greater then head.data
        // then it breaks the while loop and
        // return the value of count.
        if (min > head.data)
            break;

        count++;

        // head assign the next value of head.
        head = head.next;
    }
    return count;
}

// Function to push element in linked list.
static Node push(Node head, int data)
{
    // Allocate dynamic memory for newNode.
    Node newNode = new Node();

    // Assign the data into newNode.
    newNode.data = data;

    // newNode.next assign the address of
    // head node.
    newNode.next = (head);

    // newNode become the headNode.
    (head) = newNode;
    return head;
}

// Display linked list.
static void printList(Node node)
{
    while (node != null) {
        System.out.printf("%d ", node.data);
        node = node.next;
    }
}

// Driver functions
public static void main(String[] args)
{
  
    // Create a node and initialize with null
    Node head = null;

    // push() insert node in linked list.
    // 15.18.5.8.11.12
    head = push(head, 12);
    head = push(head, 11);
    head = push(head, 8);
    head = push(head, 5);
    head = push(head, 18);
    head = push(head, 15);

    printList(head);
    System.out.println();
    System.out.print("Linked list rotated elements: ");

    // Function call countRotation()
    System.out.print(countRotation(head) +"
");

}
}

// This code contributed by gauravrajput1