LeetCode Same Tree

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

/**
* 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) {
if(p == NULL && q == NULL)
return true;
else if(p == NULL || q== NULL)
return false;
else if(p->val == q->val)
return (isSameTree(p->left, q->left) && isSameTree(p->right, q->right));
else
return false;
}
};