Thread: Understanding nodes and how they relate to LinkedList interview questions.

return it as a linked list.

the solution had the following:

public ListNode addTwoNumbers(ListNode l1, ListNode l2)

I do not understand:
That method declaration does not return a linked list.

That method looks like it should be a private method that was used by the top level method that is adding the contents of the two linked lists. However I do not see how to handle the "carry" to the next node. EG 9 + 9 is 8 carry 1

you are given two linked lists representing two non-negative integers in reverse order. You need to add the two numbers and return the result as a linked list in reverse order. For example, if the input is (2 -> 4 -> 3) and (5 -> 6 -> 4), the output should be (7 -> 0 -> 8), which represents the sum of 342 and 465 in reverse order.

You can Try this:

**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode dummy = new ListNode(0);
ListNode curr = dummy;
int carry = 0;

while (l1 != null || l2 != null || carry != 0) {
int val1 = (l1 != null) ? l1.val : 0;
int val2 = (l2 != null) ? l2.val : 0;
int sum = val1 + val2 + carry;
carry = sum / 10;
curr.next = new ListNode(sum % 10);
curr = curr.next;
l1 = (l1 != null) ? l1.next : null;
l2 = (l2 != null) ? l2.next : null;
}

return dummy.next;
}
}

Found this solution here(https://www.techgeekbuzz.com/blog/co...iew-questions/)