using System;

using System.Collections.Generic;

namespace ValidBinarySearchTree

{

    internal class Node

    {

        public Node(int value, Node? left, Node? right) { Value = value; Left = left; Right = right; }

        public int Value { get; set; }

        public Node? Left { get; set; }

        public Node? Right { get; set; }

    }

​

    internal class Program

    {

        static void Main(string[] args)

        {

            var trees = CreateTreesForExercise();

​

            for (int idx = 0; idx < trees.Count; idx++)

            {

                var treeNumber = idx + 1;

                var treeIsValid = IsBinarySearchTreeValid(trees[idx], int.MinValue, int.MaxValue);

                Console.WriteLine($"Tree {treeNumber} is valid: {treeIsValid}");

            }

        }

​

        static bool IsBinarySearchTreeValid(Node? treeNode, int low, int high)

        {

            // Replace the contents of this method.

​

            return true; 

        }

​

        static List<Node> CreateTreesForExercise()

        {

            var trees = new List<Node>();

​

            Node tree1 = new(15, new(10, new(5, null, null), new(12, null, null)), new(25, new(17, null, null), new(27, null, null))); // true

            Node tree2 = new(3, new(2, new(1, null, null), new(4, null, null)), new(5, new(4, null, null), new(7, null, null))); // false

​

            trees.Add(tree1);

            trees.Add(tree2);

​

            return trees; 

        }

    }

}