Leetcode - Add Two Numbers - Two Solutions

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 contains a single digit. Add the two numbers and return the sum as a linked list.

Full problem here.

Solution 1. Based on this solution

var addTwoNumbers = function(l1, l2) {
    const head = new ListNode(0)

    let firstNode = l1
    let secondNode = l2
    let currentNode = head
    let carry = 0

    while (firstNode || secondNode || carry) {
        const firstValue = firstNode?.val || 0
        const secondValue = secondNode?.val || 0
        const sumOfValues = firstValue + secondValue + carry
        const remainder = sumOfValues % 10
        carry = (sumOfValues - remainder) / 10

        currentNode.next = new ListNode(remainder)
        currentNode = currentNode.next
        firstNode = firstNode?.next
        secondNode = secondNode?.next
    }

    return head.next
};

Solution 2. Based on this solution

var addTwoNumbers = function(l1, l2) {

    const getNextNode = (firstNode, secondNode, carry) => {
        const firstValue = firstNode?.val || 0
        const secondValue = secondNode?.val || 0
        const sumOfValues = firstValue + secondValue + carry
        const remainder = sumOfValues % 10
        const newCarry = (sumOfValues - remainder) / 10

        if(firstNode?.next || secondNode?.next || newCarry) {
            const nextNode = getNextNode(firstNode?.next, secondNode?.next, newCarry)
            return new ListNode(remainder, nextNode)
        }

        return new ListNode(remainder)
    }
 

    return getNextNode(l1, l2, 0)
}
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--------------------

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