Height of a Binary Tree

You are provided with an arbitrary binary tree consisting of 'N' nodes where each node is associated with a certain value. The task is to determine the height of the tree.

Explanation:

The height of a binary tree is defined as the maximum number of edges from the root to any of its leaf nodes.

Input:

The first line consists of an integer T, representing the number of test cases.

The first line of each test case contains the values of the nodes in the binary tree in level order (use -1 to represent a NULL node).

Output:

For each test case, output the height of the binary tree as a single integer.

Example:

Input:

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

Output:

4

Constraints:

• 1 <= T <= 5
• 1 <= N <= 3000
• Time Limit: 1 sec

Note:

There is no need to print anything explicitly; you only need to implement the function to solve the problem.