题目描述
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
分析：给定两个二叉树，判断这两个二叉树是否一样。
我的Code如下：
/**
* 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) {
//比较到最后的时候会出现都为null的情况
if(p==null && q==null){
return true;
}
//如果一个为空，一个不为空的情况
if(p==null || q==null){
return false;
}
boolean flag = true;
while(p!=null){
if(p.val != q.val){
return false;
}
return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
}
return flag;
}
}
