Problem Statement
Given the roots of two binary trees p
 and q
, write a function to check if they are the same or not.
Two binary trees are considered the same if they are structurally identical, and the nodes have the same value.
Example 1: Input: p = [1,2,3], q = [1,2,3] Output: true
Example 2: Input: p = [1,2], q = [1,null,2] Output: false