Same 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 isSameTree(TreeNode *p, TreeNode *q) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        return isSame(p,q);
    }
    bool isSame(TreeNode *p,TreeNode *q)
    {
        if(p==NULL&&q==NULL)
        return true;
        if(p!=NULL&&q!=NULL)
        {
            if(p->val==q->val)
            {
                return isSame(p->left,q->left)&&isSame(p->right,q->right);
            }
            else
            {
                return false;
            }
        }
        else return false;
    }
};