static void Main(string[] args) { Console.WriteLine(" enter your choice on which operator you want to operate on "); Console.WriteLine(" \n 1. linked list \n 2. Stack \n 3. Queue"); int choiceOfFunction = Convert.ToInt32(Console.ReadLine()); int i = 1; int x = 1; while (i == 1) { switch (choiceOfFunction) { case 1: // inside Interface1 objectLinkList = new LinkedList(); x = 1; while (x == 1) { Console.WriteLine("enter your choice\n 1.add 2.remove 3.display 4.sort \n"); int choice = Convert.ToInt32(Console.ReadLine()); switch (choice) { case 1: Console.WriteLine("enter the number to entered"); int val = Convert.ToInt32(Console.ReadLine()); objectLinkList.AddNewElement(val); break; case 2: objectLinkList.RemoveElement(); break; case 3: objectLinkList.Display(); break; case 4: objectLinkList.Sort(); break; default: break; } Console.WriteLine("enter 1 and 0 to exit to continue working in queue"); x = Convert.ToInt32(Console.ReadLine()); } break; case 2: Interface1 objectStack = new Stack(); x = 1; while (x == 1) { Console.WriteLine("enter your choice\n 1.add 2.remove 3.display 4.sort \n"); int choice = Convert.ToInt32(Console.ReadLine()); switch (choice) { case 1: Console.WriteLine("enter the number to entered"); int val = Convert.ToInt32(Console.ReadLine()); objectStack.AddNewElement(val); break; case 2: objectStack.RemoveElement(); break; case 3: objectStack.Display(); break; case 4: objectStack.Sort(); break; default: break; } Console.WriteLine("enter 1 to continue working in queue"); x = Convert.ToInt32(Console.ReadLine()); } break; case 3: Interface1 objectQueue = new Queue(); Queue Object2Queue = new Queue(); x = 1; while (x == 1) { Console.WriteLine("enter your choice\n 1.add 2.remove 3.display 4.sort \n"); int choice = Convert.ToInt32(Console.ReadLine()); switch (choice) { case 1: Console.WriteLine("enter the val"); int val = Convert.ToInt32(Console.ReadLine()); objectQueue.AddNewElement(val); break; case 2: objectQueue.RemoveElement(); break; case 3: objectQueue.Display(); break; case 4: objectQueue.Sort(); break; default: break; } Console.WriteLine("enter 1 to continue working in queue"); x = Convert.ToInt32(Console.ReadLine()); } break; default: Console.WriteLine("wrong choice chosen"); break; } Console.WriteLine("enter 1 to continue and 0 to exit"); i = Convert.ToInt32(Console.ReadLine()); } }