代码:
class Solution
{
public:
bool isSymmetric(TreeNode *root)
{
if (root == NULL)
{
return true;
} else
{
return gao(root->left, root->right);
}
}
private:
bool gao(TreeNode *left, TreeNode *right)
{
if (left!=NULL && right!=NULL)
{
return left->val == right->val
&& gao(left->left, right->right)
&& gao(left->right, right->left);
} else if (left==NULL && right==NULL)
{
return true;
} else
{
return false;
}
}
};