C# Лесенка

C# Лесенка

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

namespace ConsoleApplication1
{
    class Program
    {        
        static void Main(string[] args)
        {
            StairBuilder xxx = new StairBuilder();
            xxx.Start();
        }       
    }

    class StairBuilder
    {
        private int spaceCount = 0;

        public void Start()
        {
            Console.WriteLine("Enter the number of stairs: ");
            string userText = Console.ReadLine();

            bool onlyDigits = true;

            foreach (var item in userText)
            {
                if (!Char.IsDigit(item))
                {
                    onlyDigits = false;
                    Console.WriteLine("\nWrong symbol: " + item + ". Only digits are allowed.\n");
                    break;
                }
            }

            if (onlyDigits)
            {
                int stairCount = Convert.ToInt32(userText);

                for (int i = 0; i < stairCount; i++)
                    OutPutStair();

                OutPutWhiteSpaces();
                Console.WriteLine("***\n");
            }
        }

        private void OutPutWhiteSpaces()
        {
            for (int i = 0; i < spaceCount; i++)
                Console.Write(" ");
        }

        private void OutPutStair()
        {
            OutPutWhiteSpaces();
            Console.WriteLine("***");
            OutPutWhiteSpaces();
            Console.WriteLine("  *");
            spaceCount += 2;
        }
    }
}