Same Tree

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