Symmetric Tree

/**
 * Definition for binary tree
 * struct TreeNode {
 *     int val;
 *     TreeNode *left;
 *     TreeNode *right;
 *     TreeNode(int x) : val(x), left(NULL), right(NULL) {}
 * };
 */
class Solution {
public:
    bool isSymmetricSame(TreeNode *p,TreeNode *q)
    {
        if(!p&&!q)
        {
            return true;
        }
        else if((!p&&q)||(p&&!q)||(p->val!=q->val))
        {
            return false;
        }
        else
        {
            return isSymmetricSame(p->left,q->right)&&isSymmetricSame(p->right,q->left);
        }
    }
    
    bool isSymmetric(TreeNode *root) {
        if(!root)
        {
            return true;
        }
        else
        {
            /*TreeNode *p,*q;
            p=root->left;
            q=root->right;*/
            return isSymmetricSame(root->left,root->right);
            
        }
    }
};