S 12345 add new parallel module

src/main/java/com/williamfiset/algorithms/parallel/algorithm/Main.java

@@ -0,0 +1,19 @@
+package com.williamfiset.algorithms.parallel.algorithm;
+
+import java.util.concurrent.ForkJoinPool;
+
+public class Main{
+
+    public static void main(String[] args) {
+        int[] arr = {7, 6, 5, 4, 3, 2, 1};
+
+        System.out.println("available processors = " + Runtime.getRuntime().availableProcessors());
+
+        ForkJoinPool pool = new ForkJoinPool();
+        pool.invoke(new ParallelSorting(arr, 0, arr.length-1));
+
+        for (int num : arr){
+            System.out.println(num);
+        }
+    }
+}

src/main/java/com/williamfiset/algorithms/parallel/algorithm/ParallelSorting.java

@@ -0,0 +1,41 @@
+package com.williamfiset.algorithms.parallel.algorithm;
+
+import java.util.concurrent.RecursiveAction;
+
+public class ParallelSorting extends RecursiveAction{
+
+    private final int[] arr;
+    private final int low;
+    private final int high;
+
+    public ParallelSorting(int[] arr, int low, int high) {
+        this.arr = arr;
+        this.low = low;
+        this.high = high;
+    }
+
+    @Override
+    protected void compute() {
+        if (low < high) {
+            int pivotIndex = partition(arr, low, high);
+            invokeAll(new ParallelSorting(arr, low, pivotIndex - 1), new ParallelSorting(arr, pivotIndex + 1, high));
+        }
+    }
+
+    private int partition(int[] arr, int low, int high) {
+        int pivot = arr[high];
+        int i = low - 1;
+        for (int j = low; j < high; j++) {
+            if (arr[j] <= pivot) {
+                i++;
+                int temp = arr[i];
+                arr[i] = arr[j];
+                arr[j] = temp;
+            }
+        }
+        int temp = arr[i + 1];
+        arr[i + 1] = arr[high];
+        arr[high] = temp;
+        return i + 1;
+    }
+}