greater_tree.cpp

greater_tree.cpp

class Solution {
public:
    int sum =0; 
    TreeNode* convertBST(TreeNode* root) {
        if(root == nullptr)
            return nullptr; 
        convertBST(root->right);
        sum += root->val; 
        root->val = sum ;
        convertBST(root->left); 
        return root; 
    }
};