Leetcode 101 Symmetric Tree 二叉树

/**
* 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) return true;
return isSameTree(root->left, root->right);

}
bool isSameTree(TreeNode* p, TreeNode* q) {
if(!p && !q) {
return true;
}
else if(!p||!q){
return false;
}
else{
if(p->val != q->val ) return false;
else return isSameTree(p->left, q->right) && isSameTree(p->right, q->left);
}
}
};