using System;

​

public class Program

{

    public static void Main()

    {

        double height;

        double weight;

        double adultMedicationDose;

        char calculatorSelection;

        char unitSelection;

        char equationSelection;

        Console.WriteLine("Body Surface Area / Adjusted Dosage Calculator");

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

        Console.WriteLine();

        Console.WriteLine("Please enter 'A' if you want to compute patient Body Surface Area");

        Console.WriteLine("Please enter 'B' if you want to compute Adjusted Medication Dosage for child patient ");

        calculatorSelection = Convert.ToChar(Console.ReadLine().ToLower());

        //Validation

        for (;;)

        {

            if (calculatorSelection == 'a' || calculatorSelection == 'b')

            {

                break;

            }

            else

            {

                Console.WriteLine("Please enter a valid input");

                calculatorSelection = Convert.ToChar(Console.ReadLine().ToLower());

            }

        }

​

        Console.WriteLine("\nThis calculator allows you to enter both imperial and metric units\nPlease enter 'I' if you want to use imperial units\nPlease enter 'M' if you want to use metric units");

        unitSelection = Convert.ToChar(Console.ReadLine().ToLower());

        //Validation

        for (;;)

        {

            if (unitSelection == 'i' || unitSelection == 'm')

            {

                break;

            }

            else

            {

                Console.WriteLine("Please enter a valid input");

                unitSelection = Convert.ToChar(Console.ReadLine().ToLower());

            }

        }

​

        if (calculatorSelection == 'a')

        {

            Console.WriteLine("\nThis calculator allows you to calculate patient body surface area using either the DuBois formula or the Gehan formula");

            Console.WriteLine("\nPlease enter 'D' to calculate patient body surface area using either the DuBois formula\nPlease enter 'G' to calculate patient body surface area using or the Gehan formula");

            equationSelection = Convert.ToChar(Console.ReadLine().ToLower());

            for (;;)

            {

                if (equationSelection == 'g' || equationSelection == 'd')

                {

                    break;

                }

                else

                {

                    Console.WriteLine("Please enter a valid input");

                    unitSelection = Convert.ToChar(Console.ReadLine().ToLower());

                }

            }

​

            if (unitSelection == 'i')

            {

                Console.WriteLine("Patient height in inches:");

                height = Convert.ToDouble(Console.ReadLine());

                height = height * 0.0254;

                Console.WriteLine("Patient weight in pounds:");

                weight = Convert.ToDouble(Console.ReadLine());

                weight = weight * 0.453592;

                Console.WriteLine(CalculateBSA(height, weight, equationSelection));

            }

            else

            {

                Console.WriteLine("Patient height in meters:");

                height = Convert.ToDouble(Console.ReadLine());

                Console.WriteLine("Patient weight in kilograms:");

                weight = Convert.ToDouble(Console.ReadLine());

                Console.WriteLine(CalculateBSA(height, weight, equationSelection));

            }

        }

​

        if (calculatorSelection == 'b')

        {

            Console.WriteLine("Please enter adult medication dose in milligrams:");

            adultMedicationDose = Convert.ToInt32(Console.ReadLine());

            if (unitSelection == 'i')

            {

                Console.WriteLine("Patient weight in pounds:");

                weight =Convert.ToDouble(Console.ReadLine());

                weight = weight * 0.453592;

                Console.WriteLine(CalculateAdjustedDosage( weight, adultMedicationDose));

            }

            else

            {

                Console.WriteLine("Patient weight in kilograms:");

                weight = Convert.ToDouble(Console.ReadLine());

                Console.WriteLine(CalculateAdjustedDosage( weight, adultMedicationDose));

            }

        }

    }

​

    public static string CalculateBSA(double height, double weight, char formulaInd)

    {

        string result = "";

        double x = 0;

        if (formulaInd == 'd')

        {

            x = (0.20247) * (Math.Pow(height, 0.725)) * (Math.Pow(weight, 0.425));

            result = "Body Surface Area: " + Convert.ToString(x) + "m^2";

        }

​

        if (formulaInd == 'g')

        {

            x = (0.0235) * (Math.Pow((height * 100), 0.42246)) * (Math.Pow(weight, 0.51456));

            result = "Body Surface Area for this patient is: " + Convert.ToString(x) + "m^2";

        }

​

        return result;

    }

    public static string CalculateAdjustedDosage(double weight, double adultDosage)

    {

        string result = "";

        double x = 0;

        if(weight < 30 )

        {

        var percent = (weight * 2)/100;

        x = adultDosage * percent;

        }

        if(weight > 30 )

        {

        var percent = (weight + 30)/100;

        x = adultDosage * percent;

        }

        result = "The Adjusted Dosage for this medication is " + x + "mg";

        return result;

    }

}