/**
 * 
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

/* 
* You are given two non-empty linked lists representing two non-negative integers. 
* The digits are stored in reverse order and each of their nodes contain a single digit.
* Add the two numbers and return it as a linked list.
* 
* You may assume the two numbers do not contain any leading zero, except the number 0 itself.
* 
* Example:
* 
* Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
* Output: 7 -> 0 -> 8
* Explanation: 342 + 465 = 807.
*/

function ListNode(val) {
  this.val = val;
  this.next = null;
}

function addTwoNumbers(ll1, ll2) {
  let carry = 0
  let start = new ListNode()
  let dummy = start
  while(ll1 != null || ll2 != null || carry){
    let next = new ListNode((ll1 ? ll1.val : 0) + (ll2 ? ll2.val : 0) + carry)
    carry = next.val >= 10 ? 1 : 0 
    if(carry){
      next.val -= 10
    }
    dummy.next = next
    dummy = dummy.next
    if(ll1) {
      ll1 = ll1.next
    }
    if(ll2){
      ll2 = ll2.next
    }
  }
  return start.next
}

const ll1 = new ListNode(2)
ll1.next = new ListNode(4)
ll1.next.next = new ListNode(3)

const ll2 = new ListNode(5)
ll2.next = new ListNode(6)
ll2.next.next = new ListNode(4)

const ll3 = new ListNode(7)
ll3.next = new ListNode(0)
ll3.next.next = new ListNode(8)

test('add Two Numbers', () => {
  expect(addTwoNumbers(ll1, ll2)).toEqual(ll3)
});