using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        // TC 1

        //int n = 1434;

        //bool expected = false;

        // TC 2

        //int n = 1009;

        //bool expected = true;

        // TC 3

        int n = 143;

        bool expected = false;

        //bool result = IsHappy(n);

        bool result = HashSet(n);

        Console.WriteLine("Output: {0}", result);

        Console.WriteLine("Expected: {0}", expected);

    }

    public static bool IsHappy(int n)

    {

        int sum = 0;

        int digit = 0;

        int check = 0;

        int i = 0;

        while (n != 1)

        {

            while (n > 9)

            {

                digit = n % 10;

                //Console.WriteLine(n);

                n = n / 10;

                //Console.WriteLine("Before: {0}", sum);

                //Console.WriteLine("Digit: {0}", digit);

                sum += digit*digit;

                //Console.WriteLine("After: {0}", sum);

            }

            Console.WriteLine(n);

            //Console.WriteLine("Before: {0}", sum);

            //Console.WriteLine("Digit: {0}", n);

            sum += n*n;

            Console.WriteLine("Sum: {0}", sum);

            if (sum == check)

                return false;

            if (i == 10)

                check = sum;

            n = sum;

            sum = 0;

            i++;

        }

        return true;

    }

    public static bool HashSet(int n) {

        if (n < 1) return false;

        HashSet<int> nums = new HashSet<int>();

        nums.Add(n);

        while (n != 1)

        {

            int sum = 0;

            while (n > 0)

            {

                int digit = n % 10;

                sum += digit*digit;

                n /= 10;

            }

            if (nums.Contains(sum))

                return false;

            nums.Add(sum);                

            n = sum;

        }

        return true;

    }

}