【LeetCode】101. Symmetric Tree
来源:互联网 发布:为知笔记 团队 编辑:程序博客网 时间:2024/06/02 01:58
题目:
Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center).
For example, this binary tree [1,2,2,3,4,4,3]
is symmetric:
1 / \ 2 2 / \ / \3 4 4 3
But the following [1,2,2,null,3,null,3]
is not:
1 / \ 2 2 \ \ 3 3
题解:题目要求判断该树是不是对称的,要注意相比较的是左结点的右子树与右节点的左子树,而不是左子树与左子树相比较。判断是否是对称的临界条件,要找全,尤其是NULL的情况。
答案:
/**
* Definition for a binary tree node.
* struct TreeNode {
* int val;
* TreeNode *left;
* TreeNode *right;
* TreeNode(int x) : val(x), left(NULL), right(NULL) {}
* };
*/
class Solution {
public:
bool isSymmetric(TreeNode* root) {
if(root==NULL)
return 1;
return f(root->right,root->left);
}
bool f(TreeNode* r1,TreeNode* r2)
{
if(r1==NULL&&r2==NULL)
return 1;
else if(r1==NULL||r2==NULL)
return 0;
if(r1->val!=r2->val)
return 0;
return f(r1->right,r2->left)&&f(r1->left,r2->right);
}
};
- LeetCode 101. Symmetric Tree
- [LeetCode]101.Symmetric Tree
- 【LeetCode】101.Symmetric Tree
- [Leetcode] 101. Symmetric Tree
- LeetCode --- 101. Symmetric Tree
- [leetcode] 101.Symmetric Tree
- LeetCode : 101. Symmetric Tree
- [leetcode]101.Symmetric Tree
- Leetcode 101. Symmetric Tree
- 101. Symmetric Tree LeetCode
- [LeetCode]101. Symmetric Tree
- [LeetCode]101. Symmetric Tree
- [LeetCode]101. Symmetric Tree
- leetcode 101. Symmetric Tree
- LeetCode#101. Symmetric Tree
- Leetcode 101. Symmetric Tree
- Leetcode 101. Symmetric Tree
- LeetCode *** 101. Symmetric Tree
- RecyclerView条目加载图片实现LruCache三级缓存策略,有效避免 OOM , 提升系统流畅性
- 同步和异步,阻塞和非阻塞,到底区别在哪里
- nginx+keepalived构建双主负载均衡
- ArcGIS api for javascript——鼠标悬停时显示信息窗口
- lnmp源码的搭建与常见问题
- 【LeetCode】101. Symmetric Tree
- 异常控制流
- react native热更新
- 异步和同步[博客搬家]
- (原创)安卓自定义shape方法
- yum安装最新版本lnmp nginx/php配置问题
- 安卓8.0彻底改变 或告别卡慢耗电现象
- CentOS7.3+Nginx+多个Tomcat服务器转发配置搭建笔记
- loss&accuracy