Function dfs

javascript/0226-invert-binary-tree.js:14–22

(root)

};

const dfs = (root) => {
    const left = invertTree(root.left);
    const right = invertTree(root.right);

    root.left = right;
    root.right = left;

    return root;
};

/**
 * https://leetcode.com/problems/invert-binary-tree/