Add comparatod for sort Students by average score

Author: Semen Darienko

Students/src/Main.java

@@ -1,5 +1,6 @@
 import groupStudents.Group;
 import student.Student;
+import student.StudentComparatorByName;
 
 public class Main {
 
@@ -42,7 +43,16 @@ public static void main(String[] args) {
         groupA.addAll(groupB);
 
         /* Alphabetical sorting */
-        groupA.sort();
+        groupA.sort(new StudentComparatorByName());
+
+        /* Sorting by best ball*/
+        groupA.sort((o1, o2) -> {
+            double averageScore1 = o1.getAverageScore();
+            double averageScore2 = o2.getAverageScore();
+            if (averageScore1 > averageScore1) return 1;
+            else if (averageScore1 == averageScore2) return 0;
+            else return -1;
+        });
 
         /* Check if group contains in other group */
         System.out.println("Group " + groupB.getName() + (groupA.containsAll(groupB) ? " is contains" : " not contains") + " in group " + groupA.getName());

Students/src/groupStudents/Group.java

@@ -4,6 +4,7 @@
 import student.StudentComparatorByName;
 
 import java.util.ArrayList;
+import java.util.Comparator;
 import java.util.function.Predicate;
 
 public class Group extends ArrayList<Student> {

Students/src/student/Student.java

@@ -21,4 +21,12 @@ public Student(String surename){
         this.surename = surename;
         this.subjects = Subject.init();
     }
+
+    public double getAverageScore() {
+        double result = 0;
+        for (Subject s : subjects) {
+            result += s.getAverageBall();
+        }
+        return result / subjects.size();
+    }
 }