done block2

src/data_new.txt

@@ -0,0 +1,20 @@
+surname2             firstname3           patronymic3          Ж     06.12.1995   -     3     5     4756
+surname4             firstname2           patronymic3          Ж     10.09.1995   2     -     1     3291
+surname2             firstname4           patronymic4          Ж     07.05.2004   2     3     3     2103
+surname1             firstname1           patronymic2          Ж     05.05.1998   1     -     -     2766
+surname3             firstname2           patronymic3          Ч     03.02.2001   -     3     1     2260
+surname1             firstname1           patronymic2          Ж     12.04.2002   2     3     -     4495
+surname4             firstname1           patronymic3          Ж     04.09.2005   3     2     4     4183
+surname3             firstname1           patronymic2          Ж     08.07.2004   5     5     2     4345
+surname2             firstname2           patronymic1          Ч     22.01.1999   2     1     5     3870
+surname1             firstname1           patronymic1          Ч     04.05.2005   4     3     4     3302
+surname2             firstname3           patronymic3          Ж     16.12.1995   1     3     5     2801
+surname3             firstname2           patronymic3          Ж     24.08.1999   4     5     3     4139
+surname4             firstname3           patronymic4          Ч     26.07.1998   2     3     4     2548
+surname1             firstname3           patronymic1          Ч     23.06.1998   1     4     -     1092
+surname1             firstname3           patronymic2          Ж     15.10.2000   5     3     3     1577
+surname2             firstname2           patronymic2          Ч     08.12.2004   3     5     2     4394
+surname4             firstname1           patronymic3          Ч     05.08.1998   2     -     2     1404
+surname3             firstname4           patronymic3          Ж     15.12.1998   1     3     4     1133
+surname3             firstname3           patronymic2          Ч     06.09.2000   2     3     3     1118
+surname4             firstname2           patronymic3          Ж     22.12.2003   3     4     3     2677

src/main.cs

@@ -1,4 +1,4 @@
-using System.Text;
+using System.Text;
 namespace struct_lab_student
 {
 	public partial class Program
@@ -46,8 +46,7 @@ static void RunMenu(List<Student> students)
 				}
 			} while (match != 0);
 		}
-
-
+
 		static void Main()
 		{
 			Console.OutputEncoding = UTF8Encoding.UTF8;

src/methods.cs

@@ -2,67 +2,95 @@ namespace struct_lab_student
 {
 	public partial class Program
 	{
-		static void Var9(List<Student> students) { }
+		static void Var9(List<Student> students) 
+		{
+			WriteData(ProcessData(students), "data_new.txt");
+			Console.WriteLine("Дані були успішно записані у файл data_new.txt");
+		}
 
 		static void Var10(List<Student> students)
 		{
-			static double CountAverageScore(Student student)
+			foreach (var student in Filter(students, IsTalentedPhysician))
+				Console.WriteLine($"{student.surName} {student.firstName} {student.patronymic} {EvalAverage(student):0.0} {student.scholarship}");
+		}
+
+		static void Var24(List<Student> students)
+		{
+			var summer_kids = Filter(students, IsSummer);
+			foreach (var dude in summer_kids)
+				Console.WriteLine($"{dude.surName} {dude.firstName} {EvalAverage(dude)}");
+		}
+
+		static List<Student> ProcessData(List<Student> students)
+		{
+			List<Student> processedStudents = [];
+
+			foreach (var student in students)
 			{
-				char[] marks = student.Marks;
-				double sum = 0;
-				foreach (var c in marks)
-				{
-					sum += (c == '-') ? 2 : double.Parse(c.ToString());
-				}
+				char sex = student.sex;
+				if (sex == 'M' || sex == 'м' || sex == 'Ч')
+					sex = 'Ч';
+				else if (sex == 'F' || sex == 'ж' || sex == 'Ж')
+					sex = 'Ж';
 
-				return Math.Round(sum / 3, 1);
+				Student processedStudent = new()
+                {
+					surName = student.surName,
+					firstName = student.firstName,
+					patronymic = student.patronymic,
+					sex = sex,
+					dateOfBirth = student.dateOfBirth,
+					Marks = student.Marks,
+					scholarship = student.scholarship
+				};
+
+				processedStudents.Add(processedStudent);
 			}
 
-			static IEnumerable<Student> FilterTalentedPhysicians(List<Student> students)
+			return processedStudents;
+		}
+
+		static void WriteData(List<Student> students, string filename)
+		{
+			try
 			{
-				return students.Where(student => student.Marks[1] == '5');
+				StreamWriter writer = new(filename);
+				{
+					foreach (var student in students)
+					{
+						writer.WriteLine($"{student.surName,-20} {student.firstName,-20} {student.patronymic,-20} " +
+										 $"{student.sex,-5} {student.dateOfBirth,-12} {student.Marks[0],-5} {student.Marks[1],-5} {student.Marks[2],-5} " +
+										 $"{student.scholarship}");
+					}
+				}
 			}
-
-			foreach (var student in FilterTalentedPhysicians(students))
+			catch (IOException e)
 			{
-				Console.WriteLine($"{student.surName} {student.firstName} {student.patronymic} {CountAverageScore(student):0.0} {student.scholarship}");
+				Console.WriteLine($"Помилка запису у файл: {e.Message}");
 			}
 		}
 
-		static void Var24(List<Student> students)
+		public static IEnumerable<Student> Filter(List<Student> students, Func<Student, bool> Condition)
 		{
-			var summer_kids = FilterSummerKids(students);
-			foreach (var (dude, avg) in summer_kids.Zip(EvalAverages(summer_kids)))
-				Console.WriteLine($"{dude.surName} {dude.firstName} {avg:0.0}");
+			return students.Where(Condition);
 		}
 
-		public static IEnumerable<Student> FilterSummerKids(List<Student> students)
+		private static bool IsSummer(Student student)
 		{
-			return students.Where(student =>
-			{
-				if (DateTime.TryParseExact(student.dateOfBirth, "dd.MM.yyyy", null, System.Globalization.DateTimeStyles.None,
-					out DateTime date)
-					)
-				{
-					return date.Month >= 6 && date.Month <= 8;
-				}
-				return false;
-			});
+			int month = int.Parse(student.dateOfBirth[3..4]);
+			return month >= 6 && month <= 8;
 		}
 
-		public static List<double> EvalAverages(IEnumerable<Student>? students)
+		private static bool IsTalentedPhysician(Student student)
 		{
-			List<double> averages = [];
-			if (students != null)
-			{
-				foreach (var dude in students)
-				{
-					int sum = 0;
-					for (int i = 0; i < 3; i++) sum += (dude.Marks[i] == '-') ? 2 : dude.Marks[i] - '0';
-					averages.Add(sum / 3.0);
-				}
-			}
-			return averages;
+			return student.Marks[1] == '5';
+		}
+
+		public static double EvalAverage(Student student)
+		{
+			double sum = 0;
+			foreach (var c in student.Marks) sum += (c == '-') ? 2 : double.Parse(c.ToString());
+			return Math.Round(sum / 3, 1);
 		}
 	}
 }