Day31: [LeetCode简单] 101. 对称二叉树
题源:
来自leetcode题库:
https://leetcode-cn.com/problems/symmetric-tree/
代码:
dirty code凑合看吧
/**
* 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 f(vector<int> res){
if(res.size()==1) return true;
for(int i=0,j=res.size()-1;i<=j;){
if(res[i++]!=res[j--]) return false;
}
return true;
}
bool isSymmetric(TreeNode* root) {
if(!root) return true;
queue<TreeNode*> que;
que.push(root);
TreeNode* flag=new TreeNode(-9999);
while(!que.empty()){
que.push(flag);
vector<int> res;
while(1){
auto p=que.front();
que.pop();
if(p==flag) break;
if(p){
res.push_back(p->val);
que.push(p->left);
que.push(p->right);
}else{
res.push_back(-9999);
}
}
if(!f(res)) return false;
}
return true;
}
};