//ODULIO, JOSEPH PAUL

//AGULTO, JEAN DIETHERSON

//CCP 1103 - ITDC

//HAPPY NUMBER

using System;                    

public class Program 

{  

    public static int happyNumbers(int number)

    {  

        int remainder = 0; 

        int sum = 0;  

        while(number > 0)

        {  

            remainder = number%10;  

            sum = sum + (remainder*remainder);  

            number= number/10;  

        }  

        return sum;  

    }  

    public static void Main(string [] args)  

    {  

        String inputNumber;

        String answer;

        int number;  

        int result;  

        do

        {

            Console.WriteLine("Happy Numbers");

            Console.Write("Enter a Number: ");

            inputNumber = Console.ReadLine();

            if(Int32.TryParse(inputNumber, out number) == true)

            {

                if(number <1)

                {

                    Console.WriteLine("Zero or Negative Numbers is not allowed.");

                }

                else

                {

                    result = number;

                    while(result != 1 && result != 4)

                    {  

                        result = happyNumbers(result);  

                    }  

                    if(result == 1)

                    {

                        Console.WriteLine(number+ " is a happy number");  

                    }

                    else if(result == 4)  

                    {

                        Console.WriteLine(number + " is not a happy number");

                    }

                    else

                    {

                        Console.WriteLine("Invalid number.");

                    }

                }

            }

            else

            {

                Console.WriteLine("Invalid Input. Please Enter the correct value.");

            }

            Console.Write("Do you want to try again [Y/y]?. Press any key to Exit. ");

            answer = Console.ReadLine();

            Console.Clear();

        } while ((answer == "Y") || (answer == "y"));

        Console.WriteLine("End of the Program.");

    }

}