From 7cf5d446dba53b19e9a46ceb77c93da9c3e96b49 Mon Sep 17 00:00:00 2001
From: Naman Manjkhola <77687018+NamanManjkhola@users.noreply.github.com>
Date: Sun, 31 Oct 2021 21:40:48 +0530
Subject: [PATCH 1/2] Added Quick_Sort.java

---
 Java/Program 21/Quick_Sort.java | 79 +++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)
 create mode 100644 Java/Program 21/Quick_Sort.java

diff --git a/Java/Program 21/Quick_Sort.java b/Java/Program 21/Quick_Sort.java
new file mode 100644
index 0000000..fa83d35
--- /dev/null
+++ b/Java/Program 21/Quick_Sort.java	
@@ -0,0 +1,79 @@
+import java.util.Arrays;
+
+public class QuickSortDemo{
+
+    public static void main(String args[]) {
+
+        // unsorted integer array
+        int[] unsorted = {6, 5, 3, 1, 8, 7, 2, 4};
+        System.out.println("Unsorted array :" + Arrays.toString(unsorted));
+
+        QuickSort algorithm = new QuickSort();
+
+        // sorting integer array using quicksort algorithm
+        algorithm.sort(unsorted);
+
+        // printing sorted array
+        System.out.println("Sorted array :" + Arrays.toString(unsorted));
+
+    }
+
+}
+
+class QuickSort {
+
+    private int input[];
+    private int length;
+
+    public void sort(int[] numbers) {
+
+        if (numbers == null || numbers.length == 0) {
+            return;
+        }
+        this.input = numbers;
+        length = numbers.length;
+        quickSort(0, length - 1);
+    }
+
+    /*
+     * This method implements in-place quicksort algorithm recursively.
+     */
+    private void quickSort(int low, int high) {
+        int i = low;
+        int j = high;
+
+        // pivot is middle index
+        int pivot = input[low + (high - low) / 2];
+
+        // Divide into two arrays
+        while (i <= j) {
+            while (input[i] < pivot) {
+                i++;
+            }
+            while (input[j] > pivot) {
+                j--;
+            }
+            if (i <= j) {
+                swap(i, j);
+                // move index to next position on both sides
+                i++;
+                j--;
+            }
+        }
+
+        // calls quickSort() method recursively
+        if (low < j) {
+            quickSort(low, j);
+        }
+
+        if (i < high) {
+            quickSort(i, high);
+        }
+    }
+
+    private void swap(int i, int j) {
+        int temp = input[i];
+        input[i] = input[j];
+        input[j] = temp;
+    }
+}

From 80ed4077b085984f9f7dc8f4d51cb84beb268ff9 Mon Sep 17 00:00:00 2001
From: Naman Manjkhola <77687018+NamanManjkhola@users.noreply.github.com>
Date: Sun, 31 Oct 2021 21:42:07 +0530
Subject: [PATCH 2/2] Updated Readme.md

---
 Java/Readme.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Java/Readme.md b/Java/Readme.md
index a3a554a..ce2ecbe 100644
--- a/Java/Readme.md
+++ b/Java/Readme.md
@@ -24,6 +24,8 @@
 | [Program-18](https://github.com/swaaz/basicprograms/blob/814a1e60ae23d81158d8174666f23c9b7419e15e/Java/Program-18/Program%20Number%20to%20Word.java) | Program to calculate electricity bill
 | [Program-19](https://github.com/swaaz/basicprograms/blob/814a1e60ae23d81158d8174666f23c9b7419e15e/Java/Program-19/Program%20Number%20to%20Word.java) | Program to calculate discount
 | [Program-20](https://github.com/swaaz/basicprograms/blob/814a1e60ae23d81158d8174666f23c9b7419e15e/Java/Program-20/Program%20Number%20to%20Word.java) | Program to calculate batting average
+| [Program-21]() | Quicksort Sorting Algorithm in java.  
+  
   
  </div>