1038. Binary Search Tree to Greater Sum Tree

void Visit(TreeNode * &root_original,int & val , int & sum)
    {
        if(root_original==nullptr)
        {
            return;
        }else
        {
            if(root_original->val>=val)
            {
                cout << sum << endl;
                sum += root_original->val;
            }
            Visit(root_original->left,val,sum);
            Visit(root_original->right,val,sum);
        }
    }
    void Insert(TreeNode *& root,int sum)
    {
        if(root==NULL)
        {
            root = new TreeNode(sum);
        }else if(sum<root->val)
        {
            Insert(root->left,sum);
        }else if(sum>root->val)
        {
            Insert(root->right,sum);
        }
    }
    int sum = 0;
    void Call(TreeNode *& root,TreeNode *& root_2)
    {
        if(root_2==nullptr)
        {
            return;
        }else
        {
            Visit(root,root_2->val,sum);
            cout << sum << endl;
            root_2->val = sum;
            sum = 0;
        }
        Call(root,root_2->left);
        Call(root,root_2->right);
    }
    TreeNode *root_new = nullptr;
    void Deepcopy(TreeNode * &root)
    {
        if(root==NULL)
        {
            return;
        }else
        {
            Insert(root_new,root->val);
        }
        Deepcopy(root->left);
        Deepcopy(root->right);
    }
    TreeNode* bstToGst(TreeNode* root) {
        if(root==nullptr)
        {
            return nullptr;
        }else
        {
            Deepcopy(root);
            Call(root_new,root);
        }
        return root;
    }