1
var findTarget = function (root, k) {
2
  const set = new Set();
3

4
  const search = (root, k) => {
5
    if (!root) return false;
6
    if (set.has(k - root.val)) return true;
7
    set.add(root.val);
8
    return search(root.left, k) || search(root.right, k);
9
  };
10

11
  return search(root, k);
12
};