LeetCode – Refresh – Symmetric Tree

 1 /**
 2  * Definition for binary tree
 3  * struct TreeNode {
 4  *     int val;
 5  *     TreeNode *left;
 6  *     TreeNode *right;
 7  *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 8  * };
 9  */
10 class Solution {
11 public:
12     bool isS(TreeNode *t1, TreeNode *t2) {
13         if (!t1 && !t2) return true;
14         if (!t1 || !t2) return false;
15         if (t1->val != t2->val) return false;
16         return isS(t1->left, t2->right) && isS(t1->right, t2->left);
17     }
18     bool isSymmetric(TreeNode *root) {
19         if (!root) return true;
20         return isS(root->left, root->right);
21     }
22 };

posted on 2015-03-24 16:51 keepshuatishuati 阅读(126) 评论(0) 编辑收藏举报