/**
 * 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 compare(TreeNode* p, TreeNode* q)
    {
        if(p == nullptr && q == nullptr) return true;
        else if(p != nullptr && q == nullptr) return false;
        else if(p == nullptr && q != nullptr) return false;
        if(p->val != q->val) return false;
        bool left_val = compare(p->left , q->left);
        bool right_val = compare(p->right , q->right);
        return  left_val & right_val;
    }
    bool isSameTree(TreeNode* p, TreeNode* q) {
        return compare(p,q);
    }
};

/**
 * 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 track_back(TreeNode* p, TreeNode* q)
    {
        if(p==nullptr && q==nullptr) return true;
        else if(p != nullptr && q == nullptr) return false;
        else if(p == nullptr && q != nullptr) return false;
        if(p->val != q->val ) return false;
        bool left_bool = track_back(p->left , q->left);
        bool right_bool = track_back(p->right , q->right);
        return left_bool&right_bool ;
    }
    bool isSameTree(TreeNode* p, TreeNode* q) {
        return track_back(p,q); 
    }
};