Submission 2

2.ts

class ListNode {
  val: number | null;
  next: ListNode | null;
  constructor(numbers: Array<number>) {
    for (var i = 0; i < numbers.length; i++) {
      this.val = numbers[0];
      if (i + 1 === numbers.length) {
        this.next = null;
      } else {
        this.next = new ListNode(numbers.splice(i + 1));
      }
    }
  }
  extract(resultArray) {
    resultArray.push(this.val);
    while (this.next) {
      return this.next.extract(resultArray);
    }
  }
}

const addTwoNumbers = (l1: ListNode, l2: ListNode) => {
  var result = new ListNode([]);
  var l1CurrentNode = l1;
  var l2CurrentNode = l2;
  var currentResultNode = result;
  while (true) {
    const val1 = l1CurrentNode?.val || 0;
    const val2 = l2CurrentNode?.val || 0;
    const newValue = val1 + val2 + (currentResultNode.val || 0);
    console.log(newValue);
    if (newValue > 9) {
      currentResultNode.val = newValue % 10;
      currentResultNode.next = new ListNode([Math.floor(newValue / 10)]);
    } else {
      currentResultNode.val = newValue;
    }

    l1CurrentNode = l1CurrentNode?.next;
    l2CurrentNode = l2CurrentNode?.next;

    if (l1CurrentNode == null && l2CurrentNode == null) {
      break;
    }
    if (!currentResultNode.next) {
      currentResultNode.next = new ListNode([]);
    }
    currentResultNode = currentResultNode.next;
  }
  const resultArray = [];
  result.extract(resultArray);
  console.log("result", resultArray);
  return result;
};

addTwoNumbers(new ListNode([1]), new ListNode([9, 9]));