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.
[0, 100]-10^4 <= Node.val <= 10^4p = [1,2,3], q = [1,2,3]truep = [1,2], q = [1,null,2]falsep = [1,2,1], q = [1,1,2]false