Leetcode--symmetric Tree

Given a binary tree, check whether it is a mirror of the itself (ie, symmetric around its center).

For example, this binary tree is symmetric:

    1   /   2   2/\/3  4 4  3

But the following are not:

    1   /   2   2   \      3    3

Note:
Bonus points if you could solve it both recursively and iteratively.

Confused what "{1,#,2,3}" means? > read more on how binary tree is serialized on OJ.

/** * Definition for binary tree * struct TreeNode {*     int val; *     TreeNode *left; *     TreeNode *right; *     Tre Enode (int x): Val (x), left (null), right (NULL) {} *}; */class Solution {public:    bool Issymmetric (TreeNode *root)     {        if (root = NULL)            return true;        Return Issymmetric (root->left,root->right);    }    BOOL Issymmetric (treenode* left,treenode* right)    {        if (left==null && right==null)            return true;        if (left==null | | right==null)            return false;        bool L = issymmetric (left->right,right->left);        if (left->val! = Right->val)            return false;        BOOL R = issymmetric (left->left,right->right);        Return l&&r;    }};

Leetcode--symmetric Tree