对称的二叉树

题目描述

/*
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
TreeNode(int x) :
val(x), left(NULL), right(NULL) {
}
};
*/
class Solution {
public:
bool isSymmetrical(TreeNode* pRoot)
{
if(!pRoot) return true;
if(!pRoot->left&&!pRoot->right)
return true;
return Symmetrical(pRoot->left,pRoot->right);
}

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