Quick Sort

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/*Java program for implementing quick sort*/

import java.util.Scanner;

public class VSDQuickSort {
	static int n;// size of array
	static int a[];// array of numbers to be sorted
	// Method to perform quick sort

	public static void VSDquicksort(int a[], int l, int r) {
		if (l < r) {
			int p = l + (r - l) / 2;// Taking index of pivot as the mid element of array
			int pivot = a[p];// Taking pivot element
			int i = l, j = r;// Remembering initial array indices
			// Placing pivot at right place
			while (l < r) {
				if (a[l] >= pivot && a[r] <= pivot) {
					if (a[l] == pivot)
						p = r;// When the place of pivot is changed, noting its index
					if (a[r] == pivot)
						p = l;
					VSDswapElementsAt(l, r);
					r--;
				} else if (a[l] > pivot && a[r] > pivot)
					r--;
				else
					l++;
			}
			// Recursively sorting remaining elements in array
			VSDquicksort(a, i, p);
			VSDquicksort(a, p + 1, j);
		}
	}

	// Function to swap the elements of array
	public static void VSDswapElementsAt(int i, int j) {
		int temp = a[i];
		a[i] = a[j];
		a[j] = temp;
	}

	// Function to take user input
	public static void VSDuserInput() {
		Scanner sc = new Scanner(System.in);
		System.out.println("Enter size");
		n = sc.nextInt();
		a = new int[n];
		System.out.println("Enter numbers to sort:");
		for (int i = 0; i < n; i++) {
			a[i] = sc.nextInt();
		}
	}

	// Function to print output
	public static void VSDprintOutput() {
		System.out.println("The sorted order is:");
		for (int i = 0; i < n; i++) {
			System.out.println(a[i]);
		}
	}

	public static void main(String args[]) {
		VSDuserInput();
		VSDquicksort(a, 0, n - 1);
		VSDprintOutput();
	}
}