using System;

public class Program

{

    public static void Main()

    {

     //create all variables

     double initial_investment,rates, yearend_value,annual_gain,rates_add;

     int years, i;//i is a counter for loop

     String Unconverted = "";

     bool ConvertResult = false; 

     double total_return = 0;

    //seeking for the first initial investment input from user 

    //and testing for number and correct value input

    Console.WriteLine("Please enter your initial investment amount: ");

    Unconverted = Console.ReadLine();

    ConvertResult = double.TryParse(Unconverted,out initial_investment);

    if (ConvertResult && initial_investment>0)

    {

        initial_investment = Convert.ToDouble(Unconverted);

        //seeking for the second interest rates input from user 

        //and testing for number and correct value input

        Console.WriteLine("Please enter the annual rate of return (in decimal): ");

        Unconverted = Console.ReadLine();

        ConvertResult = double.TryParse(Unconverted,out rates);

        if (ConvertResult && 0<rates && rates<1)

        {

            //seeking for the third investing years input from user 

            //and testing for number and correct value input

            Console.WriteLine("Please enter the number of investing years:  ");

            Unconverted = Console.ReadLine();

            ConvertResult = int.TryParse(Unconverted,out years);

            if (ConvertResult && years>=1 && years<=100)

            {   

                //a header for the output columns

                Console.WriteLine(String.Format("{0,-7}{1,-17}{2,-15}{3,-10}","Year","Year End Value","Annual Gain","Total Return"));

                //a for loop calculating year end value, annual gain and total return for the user input investing years

                for (i=1;i<years+1;i++)

                {

                    rates_add = Convert.ToDouble(rates + 1);

                    yearend_value = Math.Round(initial_investment * (Math.Pow(rates_add,i)),2);

                    annual_gain = Math.Round(initial_investment*Math.Pow(rates_add,i) - initial_investment*Math.Pow(rates_add,i-1),2);

                    total_return = Math.Round(total_return + annual_gain,2);

                    //output result

                    Console.WriteLine(String.Format("{0,-7}{1,-17:C}{2,-15:C}{3,-10:C}",i,yearend_value,annual_gain,total_return));

                }

            }

            else

            {

                //an error meassage when the input is incorrect for investing years

                Console.WriteLine("Enter NUMBERS between 1 and 100 for investing years.");

            }

        }

        else

        {

            //an error meassage when the input is incorrect for interest rates

            Console.WriteLine("Enter NUMBERS greater than 0 and less than 1 for interest rates.");

        }

    }

    else

    {

        //an error meassage when the input is incorrect for initial investment amount

        Console.WriteLine("Enter NUMBERS greater than 0 for initial investment amount.");

    }   

    }

}

​

//Print every year and updated Future Value to the console using a loop.

// Write your code here