# Problem:

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


# Solution: Recursion

Time complexity: O(n)

Space complexity: O(n)