515-Largest_Value_in_Each_Tree_Row.html

<html>
<script>
    /**
     * Definition for a binary tree node.
     * function TreeNode(val) {
     *     this.val = val;
     *     this.left = this.right = null;
     * }
     */
    /**
     * @param {TreeNode} root
     * @return {number[]}
     */
    var largestValues = function (root) {

        let ret = [];

        let findMax = function (node, level) {
            ret[level] = (typeof ret[level] === 'undefined') ? node.val : Math.max(ret[level], node.val);
            node.left ? findMax(node.left, level + 1) : null;
            node.right ? findMax(node.right, level + 1) : null;
        }
        root ? findMax(root, 0) : null;
        return ret;
    };

</script>

</html>