Given the roots of two binary trees root and subRoot, return true if there is a node in root such that the subtree rooted at that node is identical (same structure and values) to subRoot.
Trees in this problem are given as level-order arrays: null marks a missing child, and trailing nulls are omitted.
Example:
Input: root = [3,4,5,1,2], subRoot = [4,1,2]
Output: true