gistfile1.txt

var addTwoNumbers2 = function(l1, l2, carry) {
    var sum = carry
    var hasNext = carry != 0
    var l1Next = null
    var l2Next = null
    if (l1 != null) {
        sum += l1.val
        hasNext = true
        l1Next = l1.next
    }
    if (l2 != null) {
        sum += l2.val
        hasNext = true
        l2Next = l2.next
    }
    var remainder = sum % 10
    var carry = (sum - remainder) / 10
    var next = null
    if (hasNext) {
        next = addTwoNumbers2(l1Next, l2Next, carry)
    }
    return ListNode(sum % 10, next)
}

var addTwoNumbers = function(l1, l2) {
    return addTwoNumbers2(l1, l2, 0)
};