First Commit

.gitignore

+target/
+!.mvn/wrapper/maven-wrapper.jar
+!**/src/main/**/target/
+!**/src/test/**/target/
+
+### IntelliJ IDEA ###
+.idea/modules.xml
+.idea/jarRepositories.xml
+.idea/compiler.xml
+.idea/libraries/
+*.iws
+*.iml
+*.ipr
+
+### Eclipse ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+build/
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### VS Code ###
+.vscode/
+
+### Mac OS ###
+.DS_Store
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.idea/.gitignore

+# Default ignored files
+/shelf/
+/workspace.xml

.idea/encodings.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="Encoding">
+    <file url="file://$PROJECT_DIR$/src/main/java" charset="UTF-8" />
+    <file url="file://$PROJECT_DIR$/src/main/resources" charset="UTF-8" />
+  </component>
+</project>
\ No newline at end of file

.idea/misc.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ExternalStorageConfigurationManager" enabled="true" />
+  <component name="MavenProjectsManager">
+    <option name="originalFiles">
+      <list>
+        <option value="$PROJECT_DIR$/pom.xml" />
+      </list>
+    </option>
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_19" default="true" project-jdk-name="19" project-jdk-type="JavaSDK">
+    <output url="file://$PROJECT_DIR$/out" />
+  </component>
+</project>
\ No newline at end of file

.idea/vcs.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="$PROJECT_DIR$" vcs="Git" />
+  </component>
+</project>
\ No newline at end of file

pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>org.example</groupId>
+    <artifactId>PP-01-Threads</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+        </dependency>
+    </dependencies>
+
+
+    <properties>
+        <maven.compiler.source>19</maven.compiler.source>
+        <maven.compiler.target>19</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+</project>
\ No newline at end of file

src/main/java/FibonacciCalculator.java

+public class FibonacciCalculator implements Runnable {
+    private int n;
+    private long result;
+
+    public FibonacciCalculator(int n) {
+        this.n = n;
+    }
+
+    public long getResult() {
+        return result;
+    }
+
+    @Override
+    public void run() {
+        result = fibonacci(n);
+    }
+
+    public long fibonacci(int n) {
+        if (n <= 1) {
+            return n;
+        } else {
+            return fibonacci(n - 1) + fibonacci(n - 2);
+        }
+    }
+}

src/main/java/PrimeGenerator.java

+public class PrimeGenerator implements Runnable {
+    private int start;
+    private int end;
+    private boolean[] primes;
+
+    public PrimeGenerator(int start, int end, boolean[] primes) {
+        this.start = start;
+        this.end = end;
+        this.primes = primes;
+    }
+
+    @Override
+    public void run() {
+        for (int i = start; i <= end; i++) {
+            primes[i] = isPrime(i);
+        }
+    }
+
+    private boolean isPrime(int number) {
+        if (number <= 1) {
+            return false;
+        }
+        for (int i = 2; i <= Math.sqrt(number); i++) {
+            if (number % i == 0) {
+                return false;
+            }
+        }
+        return true;
+    }
+}

src/test/java/FibonacciCalculatorTest.java

+import junit.framework.TestCase;
+
+public class FibonacciCalculatorTest extends TestCase {
+    public void testFibonacciCalculator(){
+        int n = 50; // Change this to calculate different Fibonacci numbers
+        FibonacciCalculator fib = new FibonacciCalculator(n);
+        Thread thread1 = new Thread(fib);
+
+        long startTime = System.currentTimeMillis();
+        thread1.start();
+        try {
+            thread1.join();
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        long endTime = System.currentTimeMillis();
+        long result = fib.getResult();
+        System.out.println("Fibonacci number at position " + n + " is: " + result);
+        System.out.println("\nTime taken: " + (endTime - startTime) + " milliseconds");
+
+    }
+
+    public void testFibonacciCalculatorUsingThreads(){
+        int n = 50; // Change this to calculate different Fibonacci numbers
+        FibonacciCalculator fib1 = new FibonacciCalculator(n - 1);
+        FibonacciCalculator fib2 = new FibonacciCalculator(n - 2);
+
+        Thread thread1 = new Thread(fib1);
+        Thread thread2 = new Thread(fib2);
+
+        long startTime = System.currentTimeMillis();
+
+        thread1.start();
+        thread2.start();
+
+        try {
+            thread1.join();
+            thread2.join();
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        long result = fib1.getResult() + fib2.getResult();
+        long endTime = System.currentTimeMillis();
+        System.out.println("Fibonacci number at position " + n + " is: " + result);
+        System.out.println("\nTime taken: " + (endTime - startTime) + " milliseconds");
+
+    }
+
+}

src/test/java/PrimeGeneratorTest.java

+import junit.framework.TestCase;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class PrimeGeneratorTest extends TestCase {
+
+    public void testPrimeGeneratorUsing4Threads(){
+        int n = 100000000; // Range is from 1 to 100,000,000
+        int numThreads = 4; // Number of Threads
+
+        boolean[] primes = new boolean[n + 1];
+        Thread[] threads = new Thread[numThreads];
+        int blockSize = n / numThreads;
+
+        long startTime = System.currentTimeMillis();
+
+        for (int i = 0; i < numThreads; i++) {
+            int start = i * blockSize + 1;
+            int end = (i == numThreads - 1) ? n : (i + 1) * blockSize;
+            threads[i] = new Thread(new PrimeGenerator(start, end, primes));
+            threads[i].start();
+        }
+
+        try {
+            for (Thread thread : threads) {
+                thread.join();
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // The fifth thread collects the results
+        List<Integer> finalPrimes = new ArrayList<Integer>();
+        for (int i = 1; i <= n; i++) {
+            if(primes[i])    finalPrimes.add(i);
+        }
+
+        long endTime = System.currentTimeMillis();
+
+        // for (int i : finalPrimes) {
+        //     System.out.print(i + " ");
+        // }
+
+        System.out.println("100,000,000 With 4 Threads: Time taken is " + (endTime - startTime) + " milliseconds");
+    }
+
+    public void testPrimeGeneratorUsing2Threads(){
+        int n = 100000000; // Range is from 1 to 100,000,000
+        int numThreads = 2; // Number of Threads
+
+        boolean[] primes = new boolean[n + 1];
+        Thread[] threads = new Thread[numThreads];
+        int blockSize = n / numThreads;
+
+        long startTime = System.currentTimeMillis();
+
+        for (int i = 0; i < numThreads; i++) {
+            int start = i * blockSize + 1;
+            int end = (i == numThreads - 1) ? n : (i + 1) * blockSize;
+            threads[i] = new Thread(new PrimeGenerator(start, end, primes));
+            threads[i].start();
+        }
+
+        try {
+            for (Thread thread : threads) {
+                thread.join();
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // The fifth thread collects the results
+        List<Integer> finalPrimes = new ArrayList<Integer>();
+        for (int i = 1; i <= n; i++) {
+            if(primes[i])    finalPrimes.add(i);
+        }
+
+        long endTime = System.currentTimeMillis();
+        System.out.println("100,000,000 With 2 Threads: Time taken is " + (endTime - startTime) + " milliseconds");
+    }
+
+    public void testPrimeGeneratorUsing5Threads(){
+        int n = 100000000; // Range is from 1 to 100,000,000
+        int numThreads = 5; // Number of Threads
+
+        boolean[] primes = new boolean[n + 1];
+        Thread[] threads = new Thread[numThreads];
+        int blockSize = n / numThreads;
+
+        long startTime = System.currentTimeMillis();
+
+        for (int i = 0; i < numThreads; i++) {
+            int start = i * blockSize + 1;
+            int end = (i == numThreads - 1) ? n : (i + 1) * blockSize;
+            threads[i] = new Thread(new PrimeGenerator(start, end, primes));
+            threads[i].start();
+        }
+
+        try {
+            for (Thread thread : threads) {
+                thread.join();
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // The fifth thread collects the results
+        List<Integer> finalPrimes = new ArrayList<Integer>();
+        for (int i = 1; i <= n; i++) {
+            if(primes[i])    finalPrimes.add(i);
+        }
+
+        long endTime = System.currentTimeMillis();
+        System.out.println("100,000,000 With 5 Threads: Time taken is " + (endTime - startTime) + " milliseconds");
+    }
+
+    public void testPrimeGeneratorUsing8Threads(){
+        int n = 100000000; // Range is from 1 to 100,000,000
+        int numThreads = 8; // Number of Threads
+
+        boolean[] primes = new boolean[n + 1];
+        Thread[] threads = new Thread[numThreads];
+        int blockSize = n / numThreads;
+
+        long startTime = System.currentTimeMillis();
+
+        for (int i = 0; i < numThreads; i++) {
+            int start = i * blockSize + 1;
+            int end = (i == numThreads - 1) ? n : (i + 1) * blockSize;
+            threads[i] = new Thread(new PrimeGenerator(start, end, primes));
+            threads[i].start();
+        }
+
+        try {
+            for (Thread thread : threads) {
+                thread.join();
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // The fifth thread collects the results
+        List<Integer> finalPrimes = new ArrayList<Integer>();
+        for (int i = 1; i <= n; i++) {
+            if(primes[i])    finalPrimes.add(i);
+        }
+
+        long endTime = System.currentTimeMillis();
+        System.out.println("100,000,000 With 8 Threads: Time taken is " + (endTime - startTime) + " milliseconds");
+    }
+
+
+    public void testPrimeGeneratorUsing4ThreadsWithSmallerRange(){
+        int n = 50000000; // Range is from 1 to 100,000,000
+        int numThreads = 4; // Number of Threads
+
+        boolean[] primes = new boolean[n + 1];
+        Thread[] threads = new Thread[numThreads];
+        int blockSize = n / numThreads;
+
+        long startTime = System.currentTimeMillis();
+
+        for (int i = 0; i < numThreads; i++) {
+            int start = i * blockSize + 1;
+            int end = (i == numThreads - 1) ? n : (i + 1) * blockSize;
+            threads[i] = new Thread(new PrimeGenerator(start, end, primes));
+            threads[i].start();
+        }
+
+        try {
+            for (Thread thread : threads) {
+                thread.join();
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // The fifth thread collects the results
+        List<Integer> finalPrimes = new ArrayList<Integer>();
+        for (int i = 1; i <= n; i++) {
+            if(primes[i])    finalPrimes.add(i);
+        }
+
+        long endTime = System.currentTimeMillis();
+        System.out.println("50,000,000 With 4 Threads: Time taken is " + (endTime - startTime) + " milliseconds");
+    }
+
+    public void testPrimeGeneratorUsing4ThreadsWithBiggerRange(){
+        int n = 200000000; // Range is from 1 to 100,000,000
+        int numThreads = 4; // Number of Threads
+
+        boolean[] primes = new boolean[n + 1];
+        Thread[] threads = new Thread[numThreads];
+        int blockSize = n / numThreads;
+
+        long startTime = System.currentTimeMillis();
+
+        for (int i = 0; i < numThreads; i++) {
+            int start = i * blockSize + 1;
+            int end = (i == numThreads - 1) ? n : (i + 1) * blockSize;
+            threads[i] = new Thread(new PrimeGenerator(start, end, primes));
+            threads[i].start();
+        }
+
+        try {
+            for (Thread thread : threads) {
+                thread.join();
+            }
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
+        }
+
+        // The fifth thread collects the results
+        List<Integer> finalPrimes = new ArrayList<Integer>();
+        for (int i = 1; i <= n; i++) {
+            if(primes[i])    finalPrimes.add(i);
+        }
+
+        long endTime = System.currentTimeMillis();
+        System.out.println("200,000,000 With 4 Threads: Time taken is " + (endTime - startTime) + " milliseconds");
+    }
+
+}