Largest BST Subtree Problem

Given a binary tree with 'N' nodes, determine the size of the largest subtree that is also a BST (Binary Search Tree).

Input:

The first line contains an integer 'T', representing the number of test cases.
For each test case, the first line contains space-separated integers representing the tree's level order traversal. Use '-1' to represent a null node.
Example input for a tree: 
1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1

Output:

For each test case, output a single integer: the size of the largest BST subtree within the binary tree.

Example:

Input:

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

Output:

3

Constraints:

• 1 ≤ T ≤ 100
• 1 ≤ N ≤ 5000
• 1 ≤ data ≤ 10⁵ and data ≠ -1
• Time Limit: 1 second

Note:

The level order traversal format for input assumes '-1' is used for missing children in the binary tree representation.