using System;

public class Program

{

    public static void Main()

    {

        // 1. You cannot use a double in a switch statement because of the impreciseness in the rounding. The compiler will treat numbers that are ever so slightly different as equal due to

        // not being able to store it perfectly. The switch compares values in the cases. Having imprecision can lead to errors. 1.000000000001 and 1.000000000002 would be treated equally.

        // 2. You also cannot have duplicate case values in a switch. This is because each case will check a single value inside of a case and if two cases are the same, then you would be telling the 

        // code to do 2 separate things for the same value. A case can only have one unique value to test against. 

        // 3. Cases are not allowed to have variables inside of them. They must contain constants in which they will be tested against. If a variable were to change, it would throw off the code.

        // Greet and Get Major

        string major;

        Console.WriteLine("Welcome! Please enter your major below!");

        major = Console.ReadLine();

        // Get Score

        string score;

        Console.WriteLine("Please enter your score as a whole number between 0 and 100.");

        score = Console.ReadLine();

        // Validate the score, score should be an integer (whole number)

        int intScore;

        if (!Int32.TryParse(score, out intScore))

        {Console.WriteLine("You have not entered a whole number! Please Re-Enter.");

         return;

        }

        // Validate the score, this time for the range of 0 and 100.

        int intScore2 = Convert.ToInt32(score);

        bool greater0 = intScore2>=0;

        bool less100 = intScore2<=100;

        if(!(greater0 && less100))

        {Console.WriteLine("Please enter a number between 0 and 100.");

                           return;

                           }

        // Begin the Grading scale

        string yourScore;

        if(intScore2>=90)

            {yourScore = "You get an A";}

        else if(intScore2<90 & intScore2>=80)

            {yourScore = "You get a B";}

        else if(intScore2<80 & intScore2>=70)

            {yourScore = "You get a C";}

        else if(intScore2<70 & intScore2>=60)

            {yourScore = "You get a D";}

        else

        {yourScore = "You get an F.";}

        Console.WriteLine(yourScore);

        // Check majors for strong students

        if(intScore2>=90 && major == "Information Systems")

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

        else if(intScore2>=90 && major != "Information Systems")

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

    }

}