Two Sum in a BST Problem Statement

Given a Binary Search Tree (BST) and a target value, determine if there exists a pair of node values in the BST whose sum equals the target value.

Example:

Input:

4 2 6 1 3 5 7 -1 -1 -1 -1 -1 -1 -1 -1
9

Output:

True

Explanation:

Using the tree structure defined by the level order input, find two nodes such that their value sums up to the given target value, here 9.

Constraints:

• 1 <= T <= 100
• 1 <= N <= 3000
• -10^9 <= node data <= 10^9 (node data is not -1)
• -10^9 <= target value <= 10^9

Note:

You are expected to implement the function only. The input/output operations are handled for you.