Multithreaded Quick Sort

Author: surajsbmn

Threads/src/com/cdac/threads/sorting/QuickSortMultiThreaded.java

@@ -0,0 +1,87 @@
+package com.cdac.threads.sorting;
+/*
+ * Author: Suraj Subramanian
+ * 
+ * Quick Sort implemented using Generics and Multithreading
+ * 
+ * */
+
+public class QuickSortMultiThreaded<T extends Comparable<T>> implements Runnable {
+
+	private T arr[];
+	private int start;
+	private int end;
+
+	// Driver
+	public static void main(String[] args) {
+		Integer[] data = { 5, 10, 4, 1, 2, 88, 11, 23, 13 };
+		new QuickSortMultiThreaded<Integer>().quickSort(data);
+
+		for (Integer integer : data) {
+			System.out.println(integer);
+		}
+	}
+
+	private int partition(T arr[], int start, int end) {
+		// set pivot as last element
+		T pivot = arr[end];
+		int index = start - 1;
+
+		for (int i = start; i <= end - 1; i++) {
+			if (arr[i].compareTo(pivot) < 0) {
+				index++;
+				T temp = arr[index];
+				arr[index] = arr[i];
+				arr[i] = temp;
+			}
+		}
+
+		T temp = arr[index + 1];
+		arr[index + 1] = arr[end];
+		arr[end] = temp;
+
+		return index + 1;
+	}
+
+	private void quickSort(T arr[]) {
+		Thread t = new Thread(new QuickSortMultiThreaded<T>(arr, 0, arr.length - 1));
+		t.start();
+		try {
+			t.join();
+		} catch (InterruptedException e) {
+			e.printStackTrace();
+		}
+	}
+
+	public QuickSortMultiThreaded(T arr[], int start, int end) {
+		super();
+		this.arr = arr;
+		this.start = start;
+		this.end = end;
+	}
+
+	public QuickSortMultiThreaded() {
+		super();
+	}
+
+	@Override
+	public void run() {
+		if (start < end) {
+			// partition the array
+			int partition = partition(arr, start, end);
+
+			Thread t1 = new Thread(new QuickSortMultiThreaded<T>(arr, start, partition - 1));
+			Thread t2 = new Thread(new QuickSortMultiThreaded<T>(arr, partition + 1, end));
+
+			t1.start();
+			t2.start();
+
+			try {
+				t1.join();
+			} catch (InterruptedException e) {
+				e.printStackTrace();
+			}
+		}
+	}
+
+}