AddTwoNumbersLL.java

Add Two Numbers in Linked List

class Solution {
    public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
        
        ListNode dummyHead = new ListNode(0);
        
        ListNode currentNode = dummyHead;
        
        int carry = 0, sum = 0;
        
        while(l1!=null || l2!=null || carry>0){

            int sum1 = (l1!=null) ? l1.val : 0;
            
            int sum2 = (l2!=null) ? l2.val : 0;
        
            sum = sum1 + sum2 + carry;
            
            currentNode.next = new ListNode(sum%10);
            
            currentNode = currentNode.next;
            
            carry = sum/10;
            
            if(l1!=null)
                l1 = l1.next;
            
              if(l2!=null)
                l2 = l2.next;
        }
        
        return dummyHead.next;
    }
}