Modify Main.java File

src/main/java/org/example/Main.java

-package org.example;public class Main {
+package org.example;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Main {
     public static void main(String[] args) {
-        System.out.println("Hello world!");
+        System.out.println("the first case: normal case with 4 threads");
+        FindPrimeNumbersWithMultiThreading(1,100000000,4);
+
+        System.out.println("the second case: increase the number of threads to 5 without change the search range ");
+        FindPrimeNumbersWithMultiThreading(1,100000000,5);
+        System.out.println("the second case: increase the number of threads to 10 without change the search range ");
+
+        FindPrimeNumbersWithMultiThreading(1,100000000,10);
+        System.out.println("the second case: increase the number of threads to 20 without change the search range ");
+
+        FindPrimeNumbersWithMultiThreading(1,100000000,20);
+
+//        System.out.println("the third case: change search range to 50000000 without increase the number of threads");
+//        FindPrimeNumbersWithMultiThreading(0,50000000,4);
+//        System.out.println("the third case: change search range to 20000000 without increase the number of threads");
+//        FindPrimeNumbersWithMultiThreading(0,20000000,4);
+//        System.out.println("the third case: change search range to 10000000 without increase the number of threads");
+//        FindPrimeNumbersWithMultiThreading(0,10000000,4);
+    }
+    static public void FindPrimeNumbersWithMultiThreading(int a, int b , int threadNumbers){
+        List<Thread> threads = new ArrayList<>();
+        int subRange = ((b -a)+1)/threadNumbers;
+        ArrayList<PrimeNumbersService> servers = new ArrayList<>();
+
+        for (int i=0 ; i < threadNumbers; i++){
+            int start = i*subRange + 1;
+            int end = subRange*(i+1);
+            PrimeNumbersService x = new PrimeNumbersService(start , end);
+            Thread thread = new Thread(x);
+            threads.add(thread);
+            servers.add(x);
+            thread.start();
+        }
+
+        long startTime = System.currentTimeMillis();
+        for(int i = 0; i<threadNumbers; i++){
+            try {
+                threads.get(i).join();
+            } catch (InterruptedException e) {
+                throw new RuntimeException(e);
+            }
+        }
+        List<Integer> allPrimeNumbers = new ArrayList<>();
+        for ( PrimeNumbersService service : servers){
+            allPrimeNumbers.addAll(service.getPrimeNumbers());
+        }
+        long endTime = System.currentTimeMillis();
+        System.out.println("Total prime numbers found: " + allPrimeNumbers.size());
+        System.out.println("Execution time: " + (endTime - startTime) + " milliseconds");
     }
 }
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