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

 

 

 

 

 

1 /** 2  * Definition for a binary tree node. 3  * public class TreeNode { 4  *     public int val; 5  *     public TreeNode left; 6  *     public TreeNode right; 7  *     public TreeNode(int x) { val = x; } 8  * } 9  */10 public class Solution {11     public bool IsSameTree(TreeNode p, TreeNode q) {12         if (p == null || q == null)13         {14             return p == null && q == null;15         }16         17         return p.val == q.val && IsSameTree(p.left, q.left) && IsSameTree(p.right, q.right);18     }19 }