BST Iterator Problem Statement

You are tasked with creating a class named BSTIterator that acts as an iterator for the inorder traversal of a binary search tree. Implement the following functions:

1. BSTIterator(Node root): A constructor that inputs the root of the binary search tree and initializes the iterator.
2. next(): Returns the next smallest element from the inorder traversal of the tree.
3. hasNext(): Returns true if there remains a next element in the inorder traversal; otherwise, returns false.

Assume the binary search tree contains 'N' nodes, and you must print its inorder traversal using the iterator.

Input:

The first line of the input includes an integer T representing the number of test cases.
Each test case consists of a single line with nodes in level order form, where -1 indicates a null node.
For example, the input corresponds to a tree:

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

Output:

Output for each test case should be a line containing the inorder traversal of the binary search tree.

Example:

Input:

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

Output:

1 2 3 4 5 6 7

Explanation:

Level 1:
The root node of the tree is 4

Level 2:
Left child of 4 = 2
Right child of 4 = 6

Level 3:
Left child of 2 = 1
Right child of 2 = 3
Left child of 6 = 5
Right child of 6 = 7

Level 4:
Each child node at this level is null (-1), and the input concludes with all null nodes.

The tree is traversed in inorder, hence the output is 1 2 3 4 5 6 7.

Constraints:

• 1 <= T <= 10
• 1 <= N <= 10⁴
• 1 <= A[i] <= 10⁹

Note:

The input sequence is provided in a single line separated by spaces. Implementation of the given functions is sufficient as output is handled externally.