using System;

//1) no, because switch relies on exact matching, so floating numbers like double might have precision issues when compared for equality.

//2) no, each switch must be unique. each label has to be unique. if not, you will recieve an error

//3) no, because case must be constant values that are defined during compile time. using variables as a case labe is not allowed as the variable's value may change during runtime. 

public class Program

{

    public static void Main()

    {

        double d1 = 1.00000000000000001;

        double d2 = 1.00000000000000002;

        double d3 = 1.000000000000005; // See the output for d3

        if (d1 == d2) Console.WriteLine("Both dobule numbers are represented with the same bit combination");

        Console.WriteLine("d1 = " + d1);

        Console.WriteLine("d2 = " + d2);

        Console.WriteLine("d3 = " + d3);

        Console.Write("Enter the student's major: ");

        string major = Console.ReadLine();

​

        Console.Write("Enter the student's score: ");

        string strscore = Console.ReadLine();

        int score = Convert.ToInt16(strscore);

​

        Console.WriteLine("Score: " + score);

        if (score >= 90)

        {

            Console.WriteLine("You get A.");

            if (major.Equals("Information Systems", StringComparison.OrdinalIgnoreCase))

            {

                Console.WriteLine("Congratulations! You are one of the best students in IS.");

            }

            else

            {

                Console.WriteLine("Congratulations! You are one of the best students.");

            }

        }

        else if (score >= 80 && score <= 89)

        {

            Console.WriteLine("You get B.");

        }

        else if (score >= 70 && score <= 79)

        {

            Console.WriteLine("You get C.");

        }

        else if (score >= 60 && score <= 69)

        {

            Console.WriteLine("You get D.");

        }

        else

        {

            Console.WriteLine("You get F.");

        }

    }

}