pandigital

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Diagnostics;

namespace pandigital
{
    class Program
    {
        static void Main(string[] args)
        {
            Stopwatch sw = new Stopwatch();
            sw.Start();
            UInt64 startnum = 1;
            List<UInt64> results = new List<UInt64>();
            
            do
            {
                for (int i =2; i < 10; i++)
                {
                    UInt64 x=concat(startnum,generateSec(i));
                    if (x > 999999999) break;

                    if (is9PanDigital(x))
                    {
                        results.Add(x);
                    }
                }
                startnum++;
            } while (getNumCount(startnum)<=5);
            sw.Stop();
            Console.WriteLine("Result is:{0}",results.Max());
            Console.WriteLine("Runtime:{0} Millicesonds",sw.ElapsedMilliseconds);
        }
        public static UInt64 concat(UInt64 i, List<int> l)
        {
            UInt64 res = 0;
            UInt64 p = 0;
            for (int n =l.Count-1; n >=0 ; n--)
			{
                p = i * (UInt64)l[n] * (p == 0 ? 1 : (UInt64)Math.Pow(10, getNumCount(p)));
                res += p;
			}
            return res;
        }
        public static UInt64 getNumCount(UInt64 i)
        {
            UInt64 n = 0;
            while (i > 0)
            {
                n++;
                i /= 10;
            }
            return n;
        }
        public static List<int> generateSec(int i)
        {
            List<int> res = new List<int>();
            for (int x = 0; x < i; x++)
            {
                res.Add(x + 1);
            }
            return res;
        }
        public static bool is9PanDigital(UInt64 i)
        {
            UInt64[] temp = new UInt64[9];
            for (UInt64 x = 0; x < 9; x++)
            {

                UInt64 n = i % 10;
                if (n == 0) return false;
                if (temp.Contains(n)) return false;
                temp[x] = n;
                i /= 10;
            }
            if (i != 0) return false;
            return true;
        }
    }
}