text: #ifndef LARGEST_BST_SUBTREE_HPP_
  #define LARGEST_BST_SUBTREE_HPP_
  
  #include "TreeNode.hpp"
  
  class LargestBSTSubtree {
  public:
      int largestBSTSubtree(TreeNode *root);
  
  private:
      struct Result {
          bool isBST;
          int size;
          int min;
          int max;
  
          Result(bool ib, int sz, int min, int max) : isBST(ib), size(sz), min(min), max(max) {}
      };
  
      Result helper(TreeNode *root);
  };
  
  #endif // LARGEST_BST_SUBTREE_HPP_