using System;
class Student
{
public string LastName { get; set; }
public int[] Grades { get; set; }
public double AverageGrade
{
get
{
if (Grades == null || Grades.Length == 0) return 0;
double sum = 0;
foreach (var grade in Grades)
{
sum += grade;
}
return sum / Grades.Length;
}
}
public Student(string lastName, int[] grades)
{
LastName = lastName;
Grades = grades;
}
}
class Program
{
static void Main(string[] args)
{
Console.Write("Введите количество студентов: ");
int numStudents = int.Parse(Console.ReadLine());
Student[] students = new Student[numStudents];
for (int i = 0; i < numStudents; i++)
{
Console.Write($"Введите фамилию студента {i + 1}: ");
string lastName = Console.ReadLine();
int[] grades = new int[4];
for (int j = 0; j < 4; j++)
{
Console.Write($"Введите оценку {j + 1} студента {i + 1}: ");
grades[j] = int.Parse(Console.ReadLine());
}
students[i] = new Student(lastName, grades);
}
Sort(students);
Console.WriteLine("\nОтсортированный список студентов по среднему баллу:");
foreach (var student in students)
{
Console.WriteLine($"{student.LastName}: {student.AverageGrade:F2}");
}
}
static void Sort(Student[] students)
{
Array.Sort(students, (s1, s2) => s1.AverageGrade.CompareTo(s2.AverageGrade));
}
}