Given two binary trees, 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.
Input: 1 1
/ \ / \
2 3 2 3
[1,2,3], [1,2,3]
Output: true
Input: 1 1
/ \
2 2
[1,2], [1,null,2]
Output: false
Input: 1 1
/ \ / \
2 1 1 2
[1,2,1], [1,1,2]
Output: false
/**
* Definition for a binary tree node.
* function TreeNode(val) {
* this.val = val;
* this.left = this.right = null;
* }
*/
/**
* @param {TreeNode} p
* @param {TreeNode} q
* @return {boolean}
*/
var isSameTree = function(p, q) {
if(!p||!q)return p===q
return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right)&&p.val===q.val
};