| 11 | } |
| 12 | |
| 13 | private static PartialSum addListsHelper(LinkedListNode l1, LinkedListNode l2) { |
| 14 | if (l1 == null && l2 == null) { |
| 15 | PartialSum sum = new PartialSum(); |
| 16 | return sum; |
| 17 | } |
| 18 | PartialSum sum = addListsHelper(l1.next, l2.next); |
| 19 | int val = sum.carry + l1.data + l2.data; |
| 20 | LinkedListNode full_result = insertBefore(sum.sum, val % 10); |
| 21 | sum.sum = full_result; |
| 22 | sum.carry = val / 10; |
| 23 | return sum; |
| 24 | } |
| 25 | |
| 26 | private static LinkedListNode addLists(LinkedListNode l1, LinkedListNode l2) { |
| 27 | int len1 = length(l1); |