剑指offer系列47：堆成的二叉树

 1 class Solution {
 2 public:
 3     bool isSymmetrical(TreeNode* pRoot)
 4     {
 5         return aux(pRoot, pRoot);
 6     }
 7     bool aux(TreeNode* pleft, TreeNode* pright)
 8     {
 9         if (pleft == NULL&&pright == NULL)
10             return true;
11         if (pleft == NULL || pright == NULL)
12             return false;
13         if (pleft->val != pright->val)
14             return false;
15 
16         return aux(pleft->left, pright->right) && aux( pright->right, pleft->left);
17     }
18 
19 };