【剑指offer】对称的二叉树

 1 /*
 2 struct TreeNode {
 3     int val;
 4     struct TreeNode *left;
 5     struct TreeNode *right;
 6     TreeNode(int x) :
 7             val(x), left(NULL), right(NULL) {
 8     }
 9 };
10 */
11 class Solution {
12 public:
13     bool isSymmetrical(TreeNode* pRoot1,TreeNode* pRoot2){
14         if(pRoot1 == NULL && pRoot2 == NULL)    return true;
15         if(pRoot1 == NULL || pRoot2 == NULL)    return false;
16         if(pRoot1->val != pRoot2 -> val)    return false;
17         return isSymmetrical(pRoot1->left,pRoot2->right) &&
18             isSymmetrical(pRoot1->right,pRoot2->left);
19     }
20     bool isSymmetrical(TreeNode* pRoot){
21         if(pRoot==NULL)    return true;
22         return isSymmetrical(pRoot,pRoot);
23     }
24 
25 };