static void Main(string[] args) { var tree = new BinarySearchTree(); tree.Add(100, 20, 500, 10, 30, 40); Console.WriteLine("InOrder:"); tree.InOrder(x => { Console.Write($"{x}, "); }); Console.WriteLine("\nPreOrder:"); tree.PreOrder(x => { Console.Write($"{x}, "); }); Console.WriteLine("\nPostOrder:"); tree.PostOrder(x => { Console.Write($"{x}, "); }); }