LeetCode : Same Tree

试题：
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
Accepted
358,337
Submissions
722,386

代码：

/**
 * Definition for a binary tree node.
 * public class TreeNode {
 *     int val;
 *     TreeNode left;
 *     TreeNode right;
 *     TreeNode(int x) { val = x; }
 * }
 */
class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if( (p==null&&q!=null) || (p!=null&&q==null) ){
            return false;
        }
        if(p==null&&q==null){
            return true;
        }
        
        return (p.val==q.val)&&isSameTree(p.left, q.left)&&isSameTree(p.right, q.right);
        
    }
}