Java solution to Leetcode 1609

In this Leetcode problem, we need to check the property of a binary tree:

A binary tree is named Even-Odd if it meets the following conditions:

The root of the binary tree is at level index 0, its children are at level index 1, their children are at level index 2, etc.

For every even-indexed level, all nodes at the level have odd integer values in strictly increasing order (from left to right).

For every odd-indexed level, all nodes at the level have even integer values in strictly decreasing order…