Function dfs

javascript/0543-diameter-of-binary-tree.js:20–30

(root, max)

};

const dfs = (root, max) => {
    const left = diameterOfTree(root.left, max);
    const right = diameterOfTree(root.right, max);

    const diameter = left + right;
    max[0] = Math.max(max[0], diameter);

    const height = Math.max(left, right);

    return height + 1;
};