src/main/java/dev/Main.java

@@ -1,9 +1,11 @@
 package dev;
 
+import dev.model.Student;
 import dev.service.StudentManager;
 import dev.thread.StudentLoader;
 import dev.utils.FileManager;
 
+import java.util.ArrayList;
 import java.util.List;
 import java.util.Scanner;
 
@@ -31,34 +33,36 @@ public class Main {
 
                 case 1 -> {
 
-                    List<String> data = FileManager.loadStudents("students.txt");
+                    List<String> data = FileManager.loadStudents("students.csv");
 
-                    // TODO:
+                    // Split the file into three parts
+                    List<String> part1 = data.subList(0,(data.size()/3 - 1));
 
-                    // Split data into 3 parts
+                    List<String> part2 = data.subList((data.size()/3 - 1), (2 * data.size()/3 - 1));
 
-                    List<String> part1 = null;
+                    List<String> part3 = data.subList(((2 * data.size()/3 - 1)), data.size());
 
-                    List<String> part2 = null;
+                    // Create a thread for each part
+                    StudentLoader t1 = new StudentLoader(part1);
 
-                    List<String> part3 = null;
+                    StudentLoader t2 = new StudentLoader(part2);
 
-                    // TODO:
+                    StudentLoader t3 = new StudentLoader(part3);
 
-                    StudentLoader t1 = null;
+                    // Starting all three threads
+                    t1.start();
+                    t2.start();
+                    t3.start();
 
-                    StudentLoader t2 = null;
-
-                    StudentLoader t3 = null;
-
-                    // TODO:
-
-                    // start()
-
-                    // join()
-
-                    // merge results
+                    // Waiting for all threads to finish
+                    t1.join();
+                    t2.join();
+                    t3.join();
 
+                    // Merging all lists
+                    manager.addStudents(t1.getStudents());
+                    manager.addStudents(t2.getStudents());
+                    manager.addStudents(t3.getStudents());
                 }
 
                 case 2 -> {
@@ -66,8 +70,12 @@ public class Main {
                     System.out.print("ID: ");
 
                     int id = scanner.nextInt();
-
-                    System.out.println(manager.searchStudent(id));
+                    try {
+                        System.out.println(manager.searchStudent(id).toString());
+                    }
+                    catch (NullPointerException e){
+                        System.err.println(e.getMessage());
+                    }
 
                 }
 

src/main/java/dev/model/Student.java

@@ -40,31 +40,14 @@ public class Student {
 
     @Override
     public int hashCode() {
-
-        // TODO:
-        // Return custom hash
-
-        // Example:
-        // return id % 97;
-
-        return 0;
+        return id % 97;
     }
 
     @Override
     public boolean equals(Object obj) {
-
-        // TODO:
-
-        // Step 1:
-        // Check null
-
-        // Step 2:
-        // Convert obj to Student
-
-        // Step 3:
-        // Compare IDs
-
-        return false;
+        if (obj == null) { return false; }
+        Student _obj = (Student) obj;
+        return _obj.getId() == this.getId();
     }
 
     @Override

src/main/java/dev/service/StudentManager.java

@@ -10,34 +10,27 @@ public class StudentManager {
     private final ArrayList<Student> students = new ArrayList<>();
 
     public void addStudents(ArrayList<Student> newStudents) {
-
-        // TODO:
-
-        // Merge students
-
-        // Hint:
-        // addAll()
-
+        students.addAll(newStudents);
     }
 
     public Student searchStudent(int id) {
-
-        // TODO:
-
-        // Loop through students
-
-        // Compare IDs
+        for (Student student : students){
+            if (student.getId() == id){
+                return student;
+            }
+        }
 
         return null;
     }
 
     public boolean removeStudent(int id) {
 
-        // TODO:
+        Student student = searchStudent(id);
 
-        // Find student
-
-        // Remove student
+        if (student != null){
+            students.remove(student);
+            return true;
+        }
 
         return false;
     }

src/main/java/dev/thread/StudentLoader.java

@@ -18,41 +18,30 @@ public class StudentLoader extends Thread {
     private final ArrayList<Student> students = new ArrayList<>();
 
     public StudentLoader(List<String> lines) {
-
         this.lines = lines;
     }
 
+    // Loads the database from the lines and assign its values to students array and return it
     @Override
     public void run() {
-
-        // TODO:
-
-        /*
-        Example line:
-
-        1001,Aryan,Computer Science,3.7
-         */
-
         for (String line : lines) {
+            String[] values = line.split(",");
 
-            // TODO:
-            // split line
-
-            // TODO:
-            // read values
-
-            // TODO:
-            // create Student
-
-            // TODO:
-            // add to students list
+            int id = Integer.parseInt(values[0]);
+            String name = values[1];
+            String major = values[2];
+            double gpa = Double.parseDouble(values[3]);
 
+            students.add(new Student(
+                    id,
+                    name,
+                    major,
+                    gpa
+            ));
         }
-
     }
 
     public ArrayList<Student> getStudents() {
-
         return students;
     }
 

src/main/java/dev/utils/FileManager.java

@@ -17,15 +17,10 @@ public class FileManager {
         String line;
 
         while ((line = reader.readLine()) != null) {
-
-            // TODO:
-
-            // Add line to list
-
+            lines.add(line);
         }
 
         reader.close();
-
         return lines;
     }
 

src/main/java/lecture/multithreading/timeout/Main.java

@@ -1,10 +1,41 @@
 package lecture.multithreading.timeout;
 
 
+import java.util.Scanner;
 
 public class Main {
     public static void main(String[] args) {
-        // TODO
+
+        Thread th;
+        Thread th2;
+
+        th2 = new Thread(new Runnable() {
+            @Override
+            public void run() {
+                Scanner scanner = new Scanner(System.in);
+
+                String name;
+                name = scanner.nextLine();
+                System.out.println("Hello "+ name);
+                System.exit(0);
+            }
+        });
+        th = new Thread(new Runnable(){
+            @Override
+            public void run() {
+                try {
+                    Thread.sleep(10000);
+                } catch (InterruptedException e) {
+                    throw new RuntimeException(e);
+                }
+                System.out.println("timeout!");
+                System.exit(0);
+            }
+        });
+
+        th.start();
+        th2.start();
+
     }
 }