//DE GUZMAN, ANNE VICTORIA

//FAIN, KEN IVERSON

//CCP 1103 - ITCC

//HAPPY NUMBER

​

using System;

public class HappyNumberProgram

{

    public static void Main()

    {

        string number;

        int inputNumber;

        int remainder = 0;

        int sum = 0;

        Console.WriteLine("Happy Number Program.\n");

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

        number = Console.ReadLine();

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

        {

            if(inputNumber <= 0)

            {

                 Console.WriteLine("Invalid input. Input less than or equal to zero is not allowed.");

            }

            else if(inputNumber > 20000)

            {

                Console.WriteLine("Invalid input. Input greater than 20,000 is not allowed.");

            }

            else

            {

                remainder = inputNumber%10;

                sum = sum + (remainder * remainder);

                inputNumber = inputNumber / 10;

                if(inputNumber == 1)

                {

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

                }

                else if(inputNumber == 4)

                {

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

                }

            }

        }

        else

        {

             Console.WriteLine("Invalid input. Please enter a numeric value.");

        }

    }

}