namespace ZuHeShu
{
    class Program
    {

        static void Main(string[] args)
        {

            Program p = new Program();
            Console.WriteLine("******************************组合数***********************************");
            Console.WriteLine("请任意输入一个整数:");
            string num = Console.ReadLine();
            try {
                long.Parse(num);
                List<string> als = new List<string>();
                als = p.GetData(string.Empty, num.Trim(), als);
                p.Display(als);
                Console.WriteLine("\nY-Enter:继续");
                if (Console.ReadLine().Trim().ToLower() == "y")
                {
                    Console.Clear();
                    Main(args);
                }
            }
            catch {
                Console.Clear();
                Console.WriteLine("请输入数字！");
                Main(args);
            }
        }

        private List<string> GetData(String strBase, String strSel, List<string> alRet)
        {
            if (strSel.Length == 1)
            {
                string temp=strBase + strSel;
                if (!alRet.Contains(temp)&&!temp.StartsWith("0"))
                {
                    alRet.Add(temp);
                }
            }
            else
            {
                for (int i = 0; i < strSel.Length; i++)
                {
                    GetData(strBase + strSel.Substring(i, 1), strSel.Remove(i, 1), alRet);
                }
            }
            return alRet;
        }

        public void Display(List<string> dals)
        {
            int i = 1;
            int a = dals.Count;
            if (a == 0)
            {
                Console.WriteLine("该数没有其他组合情况");
            }
            else
            {
                Console.WriteLine("不同的组合数共有" + a + "个，如下");
                foreach (string number in dals)
                {
                    Console.Write(number + "\t");
                    if (i++ % 5 == 0)
                    {
                        Console.WriteLine();
                    }
                }
            }
        }
    }
}