[C#] Số siêu xấu

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

namespace Learn_SuperUglyNumber
{
    class Program
    {
        static void Main(string[] args)
        {
            int number;
            Console.WriteLine("SUPER UGLY NUMBER");
            Console.Write("Please enter a number: ");
            string read = Console.ReadLine();
            number = int.Parse(read);
            int uglyNumber = Ugly_Number(number);
            Console.Write("Ugly Number: " + uglyNumber);
            Console.ReadKey();
        }
        private static int Ugly_Number(int number)
        {
            // cac gia tri dac biet
            if (number < 11)
            {
                if (number % 2 == 0) return number + 1;
                else return number + 2;
            }
            else if (number < 33) return 33;
            else if (number < 55) return 55;
            else if (number < 77) return 77;
            else if (number < 99) return 99;
            else if (number == 99) return 111;
            else if (number == 999) return 1111;
            else if (number == 9999) return 11111;
            // lay tong so hang
            int nLen = number.ToString().Length;
            // dua cac so hang vao trong mang
            int[] soHang = new int[nLen];
            int temp_Number = number;
            for (int i = nLen-1; i >= 0; i--)
            {
                soHang[i] = temp_Number % 10;
                temp_Number /= 10;
            }
            // lay truc doi xung
            float timTruc = (float)nLen / 2;
            int Truc = Convert.ToInt32(Math.Round(timTruc, MidpointRounding.AwayFromZero));
            int[] sieuXau = new int[Truc];
            // tim so sieu xau
            for (int i = 0; i < Truc; i++)
            {
                if (i > 0)
                {
                    if (soHang[i - 1] < sieuXau[i - 1])
                    {
                        sieuXau[i] = 1;
                        continue;
                    }
                }
                if (soHang[i] % 2 == 0)
                {
                    sieuXau[i] = soHang[i] + 1;
                    if (sieuXau[i] > 9) Tang_Gia_Tri(ref sieuXau);
                    if (sieuXau[i] > soHang[i])
                    {
                        for (int j = i + 1; j < Truc; j++) sieuXau[j] = 1;
                        break;
                    }
                }
                else sieuXau[i] = soHang[i];
            }
            if (Ghep_Sieu_Xau(sieuXau, nLen) <= number)
            {
                sieuXau[Truc-1] += 2;
                Tang_Gia_Tri(ref sieuXau);
            }
            return Ghep_Sieu_Xau(sieuXau, nLen);
        }
        private static int Ghep_Sieu_Xau(int[] sieuXau, int nLen)
        {
            string number = "";
            for (int i = 0; i < sieuXau.Length; i++)
            {
                number += sieuXau[i];
            }
            char[] newStr = number.ToCharArray();
            if (nLen % 2 == 0) number = number + Reverse(number);
            else number = number = number + Reverse(number.Substring(0, sieuXau.Length - 1));
            if (number == "") number = "0";
            int soSieuXau = int.Parse(number);
            return soSieuXau;
        }
        private static string Reverse( string s )
        {
            char[] charArray = s.ToCharArray();
            Array.Reverse( charArray );
            return new string( charArray );
        }
        private static void Tang_Gia_Tri(ref int[] sieuXau)
        {
            for (int i = sieuXau.Length-1; i >= 0; i--)
            {
                if (sieuXau[i] > 9)
                {
                    for (int j = i; j >= 0; j--)
                    {
                        if (sieuXau[j] > 9) sieuXau[j] = 1;
                        else
                        {
                            sieuXau[j] += 2;
                            return;
                        }
                    }
                }
            }
        }
    }
}