04.PasswordValidator

using System;

namespace _04.PasswordValidator
{
    class Program
    {
        static void Main(string[] args)
        {
            string password = Console.ReadLine();

            bool invalidLength = isNotValidLength(password);
            bool invalidChars = isNotValidChars(password);
            bool invalidDigits = areNotTwoDigits(password);


           if (invalidLength)
            {
                Console.WriteLine("Password must be between 6 and 10 characters");
            }
           if (invalidChars)
            {
                Console.WriteLine("Password must consist only of letters and digits");
            }
           if(invalidDigits)
            {
                Console.WriteLine("Password must have at least 2 digits");
            }
           else
            {
                Console.WriteLine("Password is valid");
            }

        }

        static bool isNotValidLength(string input)
        {
            if (input.Length >= 6 && input.Length <= 10)
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        static bool isNotValidChars(string input)
        {
            int counter = 0;
            for (int i = 0; i < input.Length; i++)
            {
                if (input[i] >= 48 && input[i] <= 57
                    || input[i] >= 65 && input[i] <= 90
                    || input[i] >= 97 && input[i] <= 122)
                {

                }
                else
                {
                    counter++;
                }
            }
            if (counter > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        static bool areNotTwoDigits(string input)
        {
            int counter = 0;
            for (int i = 0; i < input.Length; i++)
            {
                if (input[i] >= 48 && input[i] <= 57)
                {
                    counter++;
                }

            }
            if (counter >= 2)
            {
                return false;
            }
            else
            {
                return true;
            }
        }
    }
}