100. Same Tree，100sametree

100. Same Tree，100sametree

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

代碼如下：

 1 /** 2  * Definition for a binary tree node. 3  * public class TreeNode { 4  *     int val; 5  *     TreeNode left; 6  *     TreeNode right; 7  *     TreeNode(int x) { val = x; } 8  * } 9  */10 public class Solution {11     public boolean isSameTree(TreeNode p, TreeNode q) {12         if(p==null&&q==null)13         return true;14         if(p!=null&&q!=null)15         {16             if(p.val==q.val&&isSameTree(p.left,q.left)&&isSameTree(p.right,q.right))17             return true;18         }19         return false;20     }21 }