示例#1
0
    static void Main()
    {
        var n = int.Parse(Console.ReadLine());

        var set = new IndexedSet <int>();

        Console.SetOut(new System.IO.StreamWriter(Console.OpenStandardOutput())
        {
            AutoFlush = false
        });
        while (n-- > 0)
        {
            var q = Array.ConvertAll(Console.ReadLine().Split(), int.Parse);
            if (q[0] == 0)
            {
                set.Add(q[1]);
                Console.WriteLine(set.Count);
            }
            else if (q[0] == 1)
            {
                Console.WriteLine(set.Contains(q[1]) ? 1 : 0);
            }
            else if (q[0] == 2)
            {
                set.Remove(q[1]);
            }
            else
            {
                foreach (var x in set.GetItems(x => x >= q[1], x => x <= q[2]))
                {
                    Console.WriteLine(x);
                }
            }
        }
        Console.Out.Flush();
    }