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