Euler47

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Эйлер47
{
    class Program
    {
        static void Main(string[] args)
        {
            var numbersAndFactors = new Dictionary<int, List<int>>();
            foreach (var e in Enumerable.Range(0, 200000))
            {
                numbersAndFactors.Add(e, GetFactors(e));
            }
            var dictAfterSelection = numbersAndFactors.Where(x => ContainsFourPrimeFactors(x.Value));
            var keysAfterSelection = dictAfterSelection.Select(x => x.Key).ToArray();

            for(int index = 0; index<keysAfterSelection.Length - 3; index++)
            {
                if ((keysAfterSelection[index] +1 == keysAfterSelection[index + 1])
                    && (keysAfterSelection[index + 1] +1== keysAfterSelection[index + 2])
                    && (keysAfterSelection[index + 2] +1== keysAfterSelection[index + 3]))
                    Console.WriteLine(keysAfterSelection[index]);
            }
        }


        static List<int> GetFactors(int number)
        {
            int currentFactor = 2;
            List<int> result = new List<int>();
            while (number > 1)
            {
                if (number % currentFactor == 0)
                {
                    result.Add(currentFactor);
                    number /= currentFactor;
                    currentFactor = 2;
                }
                else
                    currentFactor++;
            }
            return result;
        }


        static bool ContainsFourPrimeFactors(List<int> factors)
        {
            var noRepetitionsFactors = factors.Distinct();
            if (noRepetitionsFactors.Count() == 4) return true;
            return false;
        }

    }
}