Untitled

public class Solution {

	public boolean checkRemainingNodes(ListNode head,int k)
	{
		ListNode tempNode=head;
		int count=0;

		while(tempNode.next!=null)
		{
			tempNode=tempNode.next;
			count++;

			
		}

		if(count>=k)
			return true;

		return false;
	}

	public ListNode getKthNode(ListNode head, int k)
	{
		ListNode tempNode=head;
		for(int i=0;i<k-1;i++)
		{
			tempNode=tempNode.next;
		}
		return tempNode;
	}

	public ListNode reverse(ListNode head)
	{

		ListNode prev=null;
		ListNode curr=head;

		while(curr!=null)
		{
			ListNode nextNode=curr.next;
			curr.next=prev;
			prev=curr;
			curr=nextNode;

			if(nextNode!=null)
			{
				nextNode=nextNode.next;
			}
		}
		return prev;
	}

  public void displayList(ListNode head)
  {
    ListNode tempNode=head;
    while(tempNode!=null)
    {
      System.out.print(tempNode.val+" ");
      tempNode=tempNode.next;

    }
  }
    public ListNode reverseKGroup(ListNode head, int k) {
        //You can code here

				ListNode dummyHead= new ListNode(0);
        dummyHead.next=head;

				ListNode point=dummyHead;
				

				

				while(checkRemainingNodes(point,k)){

					ListNode start=point.next;
					ListNode end = getKthNode(start,k);

					ListNode nextNode=end.next;
					end.next=null;

					
          point.next=reverse(start);
					displayList(point.next);
          start.next=nextNode;
          point=start;

				}

				return dummyHead.next;


      
    }
}