Add+two_number_in_linkedlist.java

class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {

       
        ListNode dummy=new ListNode(0);
        ListNode temp=dummy;
        int carry=0;
        while(l1!=null || l2!=null || carry==1){
            int sum=0;
            if(l1!=null){
                sum+=l1.val;
                l1=l1.next;
            }
            if(l2!=null){
                sum+=l2.val;
                l2=l2.next;
            }

            sum += carry; 
            carry = sum / 10; 
            ListNode node = new ListNode(sum % 10); 
            temp.next = node; 
            temp = temp.next; 

        }
        return dummy.next;
    }
}