### 100. Same Tree

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.

Example 1:

``````Input:     1         1
/ \       / \
2   3     2   3

[1,2,3],   [1,2,3]

Output: true``````

Example 2:

``````Input:     1         1
/           \
2             2

[1,2],     [1,null,2]

Output: false``````

Example 3:

``````Input:     1         1
/ \       / \
2   1     1   2

[1,2,1],   [1,1,2]

Output: false``````

### Analyze

``````/**
* 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 === null && q === null) {
return true
} else if (p === null || q === null) {
return false
}

if (p.val === q.val) {
return isSameTree(p.left, q.left) && isSameTree(p.right, q.right)
} else {
return false
}
};``````