[LeetCode] Sum Root to Leaf Numb

Description:

Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number.
An example is the root-to-leaf path 1->2->3 which represents the number 123.
Find the total sum of all root-to-leaf numbers.
For example,

  1
 / \
2   3

The root-to-leaf path 1->2 represents the number 12.
The root-to-leaf path 1->3 represents the number 13.
Return the sum = 12 + 13 = 25.

MySolution1:

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number}
 */
var sumNumbers = function(root) {
    var nodeQueue = [], sumQueue = [], sum = 0;
    if(root != null) {
       nodeQueue.push(root);
        sumQueue.push(root.val);
    }
    while(nodeQueue.length) {
        var currentNode = nodeQueue.shift(), currentVal = sumQueue.shift();
        if(currentNode.left == null && currentNode.right == null) {
            sum += currentVal;
        } else {
           if(currentNode.left != null) {
                nodeQueue.push(currentNode.left);
                sumQueue.push(currentVal * 10 + currentNode.left.val);
            } 
           if(currentNode.right != null) {
                nodeQueue.push(currentNode.right);
                sumQueue.push(currentVal * 10 + currentNode.right.val);
           }
        }
    }
    return sum;
};

MySolution2:

/**
 * Definition for a binary tree node.
 * function TreeNode(val) {
 *     this.val = val;
 *     this.left = this.right = null;
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number}
 */
var sumNumbers = function(root) {
    if(root === null) {
        return 0;
    }
    var sum = (arguments[1] || 0) * 10 + root.val;
    if(root.left === null && root.right === null) {
        return sum;
    }
    return sumNumbers(root.left, sum) + sumNumbers(root.right, sum);
};

Runtime: 60ms