notes and parrallel intro

Author: Ashfaqbs

Concurrency_Multithreading_and_Parallel_Computing_in_Java/.project

@@ -14,4 +14,15 @@
 	<natures>
 		<nature>org.eclipse.jdt.core.javanature</nature>
 	</natures>
+	<filteredResources>
+		<filter>
+			<id>1720793078198</id>
+			<name></name>
+			<type>30</type>
+			<matcher>
+				<id>org.eclipse.core.resources.regexFilterMatcher</id>
+				<arguments>node_modules|\.git|__CREATED_BY_JAVA_LANGUAGE_SERVER__</arguments>
+			</matcher>
+		</filter>
+	</filteredResources>
 </projectDescription>

Concurrency_Multithreading_and_Parallel_Computing_in_Java/bin/org/ashfaq/dev/problems/StudentLibrarySimulation/App.class

@@ -0,0 +1,86 @@
+package org.ashfaq.dev.parallelcomputing;
+
+public class MergeSort {
+	private int[] nums;
+
+	private int[] temparray;
+
+	public MergeSort(int[] nums) {
+		this.nums = nums;
+		this.temparray = new int[nums.length];
+		// TODO Auto-generated constructor stub
+	}
+
+	public void sort() {
+		mergesort(0, nums.length - 1);
+	}
+
+	private void mergesort(int low, int high) {
+		if (low >= high) {
+			return;
+		}
+
+		int mid = (low + high) / 2;
+
+		mergesort(low, mid);
+		mergesort(mid + 1, high);
+
+		merge(low, mid, high);
+	}
+
+	private void merge(int low, int mid, int high) {
+		for (int i = low; i <= high; i++) {
+			temparray[i] = nums[i];
+		}
+
+		int i = low;
+		int j = mid + 1;
+		int k = low;
+
+		while (i <= mid && j <= high) {
+			if (temparray[i] < temparray[j]) {
+				nums[k] = temparray[i];
+				i++;
+			} else {
+				nums[k] = temparray[j];
+				j++;
+			}
+			k++;
+		}
+
+		while (i <= mid) {
+			nums[k] = temparray[i];
+			i++;
+			k++;
+		}
+
+		while (j <= high) {
+			nums[k] = temparray[j];
+			j++;
+			k++;
+		}
+
+	}
+
+	public void swap(int i, int j) {
+		int temp = nums[i];
+		nums[i] = nums[j];
+		nums[j] = temp;
+	}
+
+	public void showArray() {
+		for (int i = 0; i < nums.length; i++) {
+			System.out.print(nums[i]+" ");
+		}
+	}
+
+	public static void main(String[] args) {
+
+		int[] arr = { 1,                                                                                                                5, 4, 3, 2, 1, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
+		MergeSort ms = new MergeSort(arr);
+		ms.sort();
+		ms.showArray();
+
+	}
+
+}

Concurrency_Multithreading_and_Parallel_Computing_in_Java/bin/org/ashfaq/dev/problems/StudentLibrarySimulation/Book.class

@@ -0,0 +1,127 @@
+package org.ashfaq.dev.parallelcomputing;
+
+public class ParallelMergeSort {
+
+	private int[] nums;
+
+	private int[] temparray;
+
+	private void parallelMergesort(int low, int high, int numOfThreads) {
+
+		if (numOfThreads <= 1) {
+			mergesort(low, high);
+			return;
+		}
+
+		int middle = (low + high) / 2;
+
+		Thread leftSorted = createThread(low, middle, numOfThreads);
+		Thread rightSorted = createThread(middle + 1, high, numOfThreads);
+
+		leftSorted.start();
+
+		rightSorted.start();
+
+		try {
+			leftSorted.join();
+			rightSorted.join();
+		} catch (InterruptedException e) {
+			// TODO Auto-generated catch block
+			e.printStackTrace();
+		}
+		
+		merge(low, middle, high);
+
+	}
+
+	public Thread createThread(int low, int high, int numOfThreads) {
+
+		return new Thread() {
+			@Override
+			public void run() {
+
+				parallelMergesort(low, high, numOfThreads / 2);
+			}
+
+		};
+	}
+
+	public ParallelMergeSort(int[] nums) {
+		this.nums = nums;
+		this.temparray = new int[nums.length];
+		// TODO Auto-generated constructor stub
+	}
+
+	public void sort() {
+		mergesort(0, nums.length - 1);
+	}
+
+	private void mergesort(int low, int high) {
+		if (low >= high) {
+			return;
+		}
+
+		int mid = (low + high) / 2;
+
+		mergesort(low, mid);
+		mergesort(mid + 1, high);
+
+		merge(low, mid, high);
+	}
+
+	private void merge(int low, int mid, int high) {
+		for (int i = low; i <= high; i++) {
+			temparray[i] = nums[i];
+		}
+
+		int i = low;
+		int j = mid + 1;
+		int k = low;
+
+		while (i <= mid && j <= high) {
+			if (temparray[i] < temparray[j]) {
+				nums[k] = temparray[i];
+				i++;
+			} else {
+				nums[k] = temparray[j];
+				j++;
+			}
+			k++;
+		}
+
+		while (i <= mid) {
+			nums[k] = temparray[i];
+			i++;
+			k++;
+		}
+
+		while (j <= high) {
+			nums[k] = temparray[j];
+			j++;
+			k++;
+		}
+
+	}
+
+	public void swap(int i, int j) {
+		int temp = nums[i];
+		nums[i] = nums[j];
+		nums[j] = temp;
+	}
+
+	public void showArray() {
+		for (int i = 0; i < nums.length; i++) {
+			System.out.print(nums[i] + " ");
+		}
+	}
+
+	public static void main(String[] args) {
+
+		int[] arr = { 1, 5, 4, 3, 2, 1, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 };
+		MergeSort ms = new MergeSort(arr);
+		ms.sort();
+		ms.showArray();
+
+	}
+
+}