25.Master Numbers

gistfile1.txt

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Numerics;
using System.Globalization;
using System.Text.RegularExpressions;

namespace Praktice
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = int.Parse(Console.ReadLine());

            List<int> symetric = FindSymetrics(a);
            List<int> divisible = DivisbleBy7(symetric);
            List<int> master = HoldEvenDigith(divisible);
            foreach (var item in master)
            {
                Console.WriteLine(item);
            }
        }

        private static List<int> HoldEvenDigith(List<int> divisible)
        {
            List<int> result = new List<int>();
            foreach (var item in divisible)
            {
                string a = item.ToString();
                for (int i = 0; i < a.Length; i++)
                {
                    char b = a[i];
                    int c = int.Parse(b.ToString());
                    if (c % 2 == 0)
                    {
                        if (!result.Contains(item))
                        {
                            result.Add(item);
                        }                       
                    }
                }                
            }
            return result;
        }

        private static List<int> DivisbleBy7(List<int> symetric)
        {
            List<int> result = new List<int>();
           
            foreach (var num in symetric)
            {
                int sum = 0;
                int b = num;
                while (b > 0)
                {                  
                  int a = b % 10;
                  b = b / 10;
                  sum += a;
                }
                if (sum%7==0)
                {
                    result.Add(num);
                }
            }
            return result;
        }

        private static List<int> FindSymetrics(int a)
        {
            List<int> result = new List<int>();
            for (int i = 0; i < a; i++)
            {
                int num = i;
                int reverse = 0;
                while (num > 0)
                {
                    int remainder = num % 10;
                    reverse = reverse * 10 + remainder;
                    num /= 10;
                    if (i == reverse)
                    {
                        result.Add(i);
                    }
                }
            }
            
            return result;
        }
    }
}