Function dfs

javascript/0230-kth-smallest-element-in-a-bst.js:14–22

(root, k, inOrder)

};

const dfs = (root, k, inOrder) => {
    if (root.left) kthSmallest(root.left, k, inOrder);

    inOrder.push(root.val);

    if (root.right) kthSmallest(root.right, k, inOrder);

    return inOrder[k - 1];
};

/**
 * https://leetcode.com/problems/kth-smallest-element-in-a-bst/