Untitled

using System;

namespace TinhGPA
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.Write("Ho va ten: ");
            string hoten = Console.ReadLine();
            Console.Write("Lop: ");
            string lop = Console.ReadLine();
            Console.Write("Diem_QTH: ");
            double qth = Convert.ToDouble(Console.ReadLine());
            Console.Write("Diem_HTTQL: ");
            double httql = Convert.ToDouble(Console.ReadLine());
            Console.Write("Diem_CSLT: ");
            double cslt = Convert.ToDouble(Console.ReadLine());
            Console.Write("Diem_Triet: ");
            double triet = Convert.ToDouble(Console.ReadLine());

            double gpaQTH = ConvertToGPA(qth);
            double gpaHTTQL = ConvertToGPA(httql);
            double gpaCSLT = ConvertToGPA(cslt);
            double gpaTriet = ConvertToGPA(triet);

            double gpa = (gpaQTH + gpaHTTQL + gpaCSLT + gpaTriet) / 4;

            Console.WriteLine($"Sinh vien {hoten.ToUpper()}, Lop {lop}, Dat GPA {gpa},");

            if (gpa >= 3.6)
            {
                Console.WriteLine("Xep loai Xuat Sac");
            }
            else if (gpa >= 3.2)
            {
                Console.WriteLine("Xep loai Gioi");
            }
            else if (gpa >= 2.5)
            {
                Console.WriteLine("Xep loai Kha");
            }
            else if (gpa >= 2.0)
            {
                Console.WriteLine("Xep loai Trung Binh");
            }
            else
            {
                Console.WriteLine("Xep loai Yeu");
            }
        }
        static double ConvertToGPA(double diemThang10)
        {
            if (diemThang10 >= 8.5)
                return 4.0;
            else if (diemThang10 >= 7.0)
                return 3.0;
            else if (diemThang10 >= 5.5)
                return 2.0;
            else
                return 1.0;
        }
    }
}