Test5-Next Number

Given a large number represented in the form of a linked list. Write code to increment the number by 1 in-place(i.e. without using extra space).
Note: You don't need to print the elements, just update the elements and return the head of updated LL.
Input Constraints:
1 <= Length of Linked List <=10^6.
Input format :
Line 1 : Linked list elements (separated by space and terminated by -1)
Output Format :
Line 1: Updated linked list elements 
Sample Input 1 :
3 9 2 5 -1
Sample Output 1 :
3 9 2 6
Sample Input 2 :
9 9 9 -1
Sample Output 1 :
1 0 0 0 

***********************************Solution******************************************

public class Solution {


	public static LinkedListNode<Integer> nextLargeNumber(LinkedListNode<Integer> head) {
		LinkedListNode<Integer> temp;
		LinkedListNode<Integer> prev= null;
		LinkedListNode<Integer> curr= head;

		while(curr!=null)
		{
			temp=curr.next;
			curr.next=prev;
			prev=curr;
			curr=temp;
		}
		LinkedListNode<Integer> tem=prev;
		int cnt=0;
		LinkedListNode<Integer> a=new LinkedListNode<>(1);
		while(tem!=null)
		{
			if(tem.data==9)
			{
				tem.data=0;
				cnt=1;
				if(tem.next==null)
					tem.next=a;
			}
			else
			{
				if(cnt==1)
				{
					int d=tem.data+1;
					if(d==10)
					{
						tem.data=0;
						cnt=1;
					}
					else{
						cnt=0;
					}
				}
				else{
					tem.data=tem.data+1;
					break;
				}
			}
			tem=tem.next;
		}
		LinkedListNode<Integer> temp1;
		LinkedListNode<Integer> prev1=null;
		LinkedListNode<Integer> curr1=prev;
		while(curr1!=null)
		{
			temp1=curr1.next;
            curr1.next=prev1;
            prev1=curr1;
            curr1=temp1;
        }
        return prev1;
		
	}


}