Problem 41

using System;
using System.Diagnostics;
using System.Linq;

namespace Problem39
{
    class Program
    {
        static bool[] notPrime = new bool[7654321];
        static void SetupPrimes()
        {
            notPrime[0] = true;
            notPrime[1] = true;
            for (var i = 7000000; i <= Math.Sqrt(notPrime.Length); i++)
            {
                if (notPrime[i]) continue;
                for (var j = i * 2; j < notPrime.Length; j += i)
                {
                    notPrime[j] = true;
                }
            }
        }
        static bool IsPandigital(int input)
        {
            var n = input.ToString().Length;
            var outarry = Array.ConvertAll(input.ToString().ToArray(), x => (int)x - 48);
            var dict = new bool[10];
            var flag = true;
            foreach (var v in outarry)
            {
                if (dict[v])
                {
                    flag = false;
                }
                dict[v] = true;
            }
            for (var i = 1; i <= n; i++)
            {
                if (!dict[i])
                {
                    flag = false;
                }
            }
            return flag;
        }
        static void Main(string[] args)
        {
            var sw = new Stopwatch();
            sw.Start();
            SetupPrimes();
            for (var i = 7654320; i > 0; i--)
            {
                if (!IsPandigital(i) || notPrime[i]) continue;
                Console.WriteLine(i);
                break;
            }
            sw.Stop();
            Console.WriteLine("Solution took {0}ms", sw.ElapsedMilliseconds);
            Console.ReadLine();
        }
    }
}