namespace ConsoleApplication1 { using System; class Program { static void Main(string[] args) { //Perform the operation. bool[] doors = new bool[100]; int n = 0; int d; while ((d = (++n * n)) <= 100) doors[d - 1] = true; //Perform the presentation. for (d = 0; d < doors.Length; d++) Console.WriteLine("Door #{0}: {1}", d + 1, doors[d] ? "Open" : "Closed"); Console.ReadKey(true); } } }