/** * Definition for a binary tree node. * struct TreeNode { * int val; * TreeNode *left; * TreeNode *right; * TreeNode() : val(0), left(nullptr), right(nullptr) {} * TreeNode(int x) : val(x), left(nullptr), right(nullptr) {} * TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {} * }; */ 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; if (p == NULL || q == NULL) return false; return (p->val == q->val) && isSameTree(p->left, q->left) && isSameTree(p->right, q->right); } };