Find the number of occurrences of a number in an array

.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
\ No newline at end of file

.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>
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.idea/workspace.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="AutoImportSettings">
+    <option name="autoReloadType" value="SELECTIVE" />
+  </component>
+  <component name="ChangeListManager">
+    <list default="true" id="bd82bf16-4018-4075-b7d4-6d792f3cd58b" name="Changes" comment="">
+      <change afterPath="$PROJECT_DIR$/.gitignore" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/encodings.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/misc.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/vcs.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/.idea/workspace.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/pom.xml" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/main/java/Service/NumOfOccurrences.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/src/test/java/NumOfOccurrencesTest.java" afterDir="false" />
+    </list>
+    <option name="SHOW_DIALOG" value="false" />
+    <option name="HIGHLIGHT_CONFLICTS" value="true" />
+    <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
+    <option name="LAST_RESOLUTION" value="IGNORE" />
+  </component>
+  <component name="FileTemplateManagerImpl">
+    <option name="RECENT_TEMPLATES">
+      <list>
+        <option value="Class" />
+      </list>
+    </option>
+  </component>
+  <component name="Git.Settings">
+    <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$" />
+  </component>
+  <component name="MarkdownSettingsMigration">
+    <option name="stateVersion" value="1" />
+  </component>
+  <component name="ProjectId" id="2NKl3Ma6JBhu4WPrU4yJSnzE8yx" />
+  <component name="ProjectLevelVcsManager" settingsEditedManually="true" />
+  <component name="ProjectViewState">
+    <option name="hideEmptyMiddlePackages" value="true" />
+    <option name="showLibraryContents" value="true" />
+  </component>
+  <component name="PropertiesComponent"><![CDATA[{
+  "keyToString": {
+    "RunOnceActivity.OpenProjectViewOnStart": "true",
+    "RunOnceActivity.ShowReadmeOnStart": "true",
+    "SHARE_PROJECT_CONFIGURATION_FILES": "true"
+  }
+}]]></component>
+  <component name="SpellCheckerSettings" RuntimeDictionaries="0" Folders="0" CustomDictionaries="0" DefaultDictionary="application-level" UseSingleDictionary="true" transferred="true" />
+  <component name="TaskManager">
+    <task active="true" id="Default" summary="Default task">
+      <changelist id="bd82bf16-4018-4075-b7d4-6d792f3cd58b" name="Changes" comment="" />
+      <created>1679420459839</created>
+      <option name="number" value="Default" />
+      <option name="presentableId" value="Default" />
+      <updated>1679420459839</updated>
+    </task>
+    <servers />
+  </component>
+  <component name="Vcs.Log.Tabs.Properties">
+    <option name="TAB_STATES">
+      <map>
+        <entry key="MAIN">
+          <value>
+            <State />
+          </value>
+        </entry>
+      </map>
+    </option>
+  </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>rosette_alwazzeh</artifactId>
+    <version>1.0-SNAPSHOT</version>
+    <dependencies>
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </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/Service/NumOfOccurrences.java

+package Service;
+import java.util.Arrays;
+import java.util.concurrent.RecursiveAction;
+
+public class NumOfOccurrences extends RecursiveAction{
+
+    public long occur=0;
+
+    int arr[], num,lo, hi;
+
+    public NumOfOccurrences(int[] arr, int num, int lo, int hi) {
+        this.arr = arr;
+        this.num = num;
+        this.lo=lo;
+        this.hi=hi;
+    }
+
+    public long computeSeq() {
+
+        for (int i = lo; i <= hi; ++i) {
+            if (arr[i]==num)
+                occur++;
+        }
+        return occur;
+    }
+
+    @Override
+    protected void compute() {
+        if (hi - lo > 125000000) {
+            int mid = (lo + hi) / 2;
+            NumOfOccurrences left = new NumOfOccurrences (arr,num, lo, mid);
+            NumOfOccurrences right = new NumOfOccurrences (arr,num ,mid + 1, hi);
+            left.fork();
+            right.compute();
+            left.join();
+            occur = left.occur + right.occur;
+        } else {
+            occur =computeSeq();
+        }
+    }
+
+    public void computeParallelStream() {
+        occur = Arrays.stream(arr).asLongStream().parallel().filter(a->a==num).count();
+    }
+
+    public void computeStream() {
+        occur = Arrays.stream(arr).asLongStream().filter(a->a==num).count();
+    }
+}

src/test/java/NumOfOccurrencesTest.java

+
+import Service.NumOfOccurrences;
+import junit.framework.TestCase;
+import java.util.Random;
+import java.util.concurrent.ForkJoinPool;
+
+
+public class NumOfOccurrencesTest extends TestCase {
+
+    Random rand = new Random();
+    int num=919;
+
+    int size = 1000_000_000;
+
+
+    private int[] randomArray(int size) {
+        long s = 115;
+        rand.setSeed(s);
+        int[] arr = new int[size];
+        for (int i = 0; i < size; i++) {
+            arr[i] = (rand.nextInt(100000)+1);
+        }
+        return arr;
+    }
+
+    public void testNumOfOccurrencesSeq() {
+
+        int[] arr = randomArray(size);
+
+        NumOfOccurrences array = new NumOfOccurrences(arr, num,0, arr.length - 1);
+
+        long start = System.currentTimeMillis();
+        long occur = array.computeSeq();
+        long endTimer = System.currentTimeMillis() - start;
+        System.out.printf("Sequential Time execution for Random Array of size %d is %d ms,the number of occurrences of %d in Array is %d\n", size, endTimer, num,
+                occur);
+    }
+
+    public void testNumOfOccurrencesPP() {
+        System.setProperty("java.util.concurrent.ForkJoinPool.common.parallelism","7");
+
+        int[] arr = randomArray(size);
+
+        NumOfOccurrences array = new NumOfOccurrences(arr, num,0, arr.length - 1);
+        long start = System.currentTimeMillis();
+        ForkJoinPool.commonPool().invoke(array);
+        long endTimer = System.currentTimeMillis() - start;
+        System.out.printf("Parallel Time execution for Random Array of size %d is %d ms, the number of occurrences of %d in Array is %d\n", size, endTimer, num,
+                array.occur);
+    }
+
+
+    public void testComputeStream(){
+        System.setProperty("java.util.concurrent.ForkJoinPool.common.parallelism","7");
+
+        int[] arr = randomArray(size);
+
+        NumOfOccurrences array = new NumOfOccurrences(arr, num,0, arr.length - 1);
+        long start = System.currentTimeMillis();
+        array.computeStream();
+        long endTimer = System.currentTimeMillis() - start;
+        System.out.printf("Sequential Stream Time execution for Random Array of size %d is %d ms, the number of occurrences of %d in Array is %d\n", size, endTimer, num,
+                array.occur);
+
+    }
+
+    public void testComputeParallelStream(){
+        System.setProperty("java.util.concurrent.ForkJoinPool.common.parallelism","7");
+
+        int[] arr = randomArray(size);
+
+        NumOfOccurrences array = new NumOfOccurrences(arr, num,0, arr.length - 1);
+        long start = System.currentTimeMillis();
+        array.computeParallelStream();
+        long endTimer = System.currentTimeMillis() - start;
+        System.out.printf("Parallel Stream Time execution for Random Array of size %d is %d ms, the number of occurrences of %d in Array is %d\n", size, endTimer, num,
+                array.occur);
+
+    }
+
+
+}