Binary Tree Diameter Problem Statement

You are given a Binary Tree, and you need to determine the length of the diameter of the tree.

The diameter of a binary tree is the length of the longest path between any two end nodes in the tree.

Input:

The first line contains an integer 'T', representing the number of test cases. Each test case consists of a single line listing the tree nodes in level order, with nodes separated by spaces. Use -1 to denote a null node.

Output:

For each test case, output a single integer representing the diameter of the binary tree. Each result should be printed on a new line.

Example:

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

Output:
6

Explanation:

The provided input represents a binary tree. The nodes contributing to the diameter are highlighted, and the length of the path between them is 6.

Constraints:

• 1 ≤ T ≤ 10
• 0 ≤ N ≤ 105
• 1 ≤ data ≤ 104

Where ‘N’ is the total number of nodes in the binary tree, and 'data' represents the node values.

Note: You are not required to handle input/output operations. Implement the function to compute the result.